There are more AWS SDK examples available in the AWS Doc SDK Examples
DynamoDB examples using SDK for Java 2.x
The following code examples show you how to perform actions and implement common scenarios by using the AWS SDK for Java 2.x with DynamoDB.
Basics are code examples that show you how to perform the essential operations within a service.
Actions are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios.
Scenarios are code examples that show you how to accomplish specific tasks by calling multiple functions within a service or combined with other AWS services.
Each example includes a link to the complete source code, where you can find instructions on how to set up and run the code in context.
Get started
The following code examples show how to get started using DynamoDB.
- SDK for Java 2.x
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Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ListTablesRequest; import software.amazon.awssdk.services.dynamodb.model.ListTablesResponse; import java.util.List; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class ListTables { public static void main(String[] args) { System.out.println("Listing your Amazon DynamoDB tables:\n"); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); listAllTables(ddb); ddb.close(); } public static void listAllTables(DynamoDbClient ddb) { boolean moreTables = true; String lastName = null; while (moreTables) { try { ListTablesResponse response = null; if (lastName == null) { ListTablesRequest request = ListTablesRequest.builder().build(); response = ddb.listTables(request); } else { ListTablesRequest request = ListTablesRequest.builder() .exclusiveStartTableName(lastName).build(); response = ddb.listTables(request); } List<String> tableNames = response.tableNames(); if (tableNames.size() > 0) { for (String curName : tableNames) { System.out.format("* %s\n", curName); } } else { System.out.println("No tables found!"); System.exit(0); } lastName = response.lastEvaluatedTableName(); if (lastName == null) { moreTables = false; } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } System.out.println("\nDone!"); } }
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For API details, see ListTables in AWS SDK for Java 2.x API Reference.
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Basics
The following code example shows how to:
Create a table that can hold movie data.
Put, get, and update a single movie in the table.
Write movie data to the table from a sample JSON file.
Query for movies that were released in a given year.
Scan for movies that were released in a range of years.
Delete a movie from the table, then delete the table.
- SDK for Java 2.x
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Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Create a DynamoDB table.
// Create a table with a Sort key. public static void createTable(DynamoDbClient ddb, String tableName) { DynamoDbWaiter dbWaiter = ddb.waiter(); ArrayList<AttributeDefinition> attributeDefinitions = new ArrayList<>(); // Define attributes. attributeDefinitions.add(AttributeDefinition.builder() .attributeName("year") .attributeType("N") .build()); attributeDefinitions.add(AttributeDefinition.builder() .attributeName("title") .attributeType("S") .build()); ArrayList<KeySchemaElement> tableKey = new ArrayList<>(); KeySchemaElement key = KeySchemaElement.builder() .attributeName("year") .keyType(KeyType.HASH) .build(); KeySchemaElement key2 = KeySchemaElement.builder() .attributeName("title") .keyType(KeyType.RANGE) .build(); // Add KeySchemaElement objects to the list. tableKey.add(key); tableKey.add(key2); CreateTableRequest request = CreateTableRequest.builder() .keySchema(tableKey) .provisionedThroughput(ProvisionedThroughput.builder() .readCapacityUnits(10L) .writeCapacityUnits(10L) .build()) .attributeDefinitions(attributeDefinitions) .tableName(tableName) .build(); try { CreateTableResponse response = ddb.createTable(request); DescribeTableRequest tableRequest = DescribeTableRequest.builder() .tableName(tableName) .build(); // Wait until the Amazon DynamoDB table is created. WaiterResponse<DescribeTableResponse> waiterResponse = dbWaiter.waitUntilTableExists(tableRequest); waiterResponse.matched().response().ifPresent(System.out::println); String newTable = response.tableDescription().tableName(); System.out.println("The " + newTable + " was successfully created."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } }
Create a helper function to download and extract the sample JSON file.
// Load data into the table. public static void loadData(DynamoDbClient ddb, String tableName, String fileName) throws IOException { DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder() .dynamoDbClient(ddb) .build(); DynamoDbTable<Movies> mappedTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class)); JsonParser parser = new JsonFactory().createParser(new File(fileName)); com.fasterxml.jackson.databind.JsonNode rootNode = new ObjectMapper().readTree(parser); Iterator<JsonNode> iter = rootNode.iterator(); ObjectNode currentNode; int t = 0; while (iter.hasNext()) { // Only add 200 Movies to the table. if (t == 200) break; currentNode = (ObjectNode) iter.next(); int year = currentNode.path("year").asInt(); String title = currentNode.path("title").asText(); String info = currentNode.path("info").toString(); Movies movies = new Movies(); movies.setYear(year); movies.setTitle(title); movies.setInfo(info); // Put the data into the Amazon DynamoDB Movie table. mappedTable.putItem(movies); t++; } }
Get an item from a table.
public static void getItem(DynamoDbClient ddb) { HashMap<String, AttributeValue> keyToGet = new HashMap<>(); keyToGet.put("year", AttributeValue.builder() .n("1933") .build()); keyToGet.put("title", AttributeValue.builder() .s("King Kong") .build()); GetItemRequest request = GetItemRequest.builder() .key(keyToGet) .tableName("Movies") .build(); try { Map<String, AttributeValue> returnedItem = ddb.getItem(request).item(); if (returnedItem != null) { Set<String> keys = returnedItem.keySet(); System.out.println("Amazon DynamoDB table attributes: \n"); for (String key1 : keys) { System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString()); } } else { System.out.format("No item found with the key %s!\n", "year"); } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } }
Full example.
/** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * This Java example performs these tasks: * * 1. Creates the Amazon DynamoDB Movie table with partition and sort key. * 2. Puts data into the Amazon DynamoDB table from a JSON document using the * Enhanced client. * 3. Gets data from the Movie table. * 4. Adds a new item. * 5. Updates an item. * 6. Uses a Scan to query items using the Enhanced client. * 7. Queries all items where the year is 2013 using the Enhanced Client. * 8. Deletes the table. */ public class Scenario { public static final String DASHES = new String(new char[80]).replace("\0", "-"); public static void main(String[] args) throws IOException { final String usage = """ Usage: <fileName> Where: fileName - The path to the moviedata.json file that you can download from the Amazon DynamoDB Developer Guide. """; if (args.length != 1) { System.out.println(usage); System.exit(1); } String tableName = "Movies"; String fileName = args[0]; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); System.out.println(DASHES); System.out.println("Welcome to the Amazon DynamoDB example scenario."); System.out.println(DASHES); System.out.println(DASHES); System.out.println( "1. Creating an Amazon DynamoDB table named Movies with a key named year and a sort key named title."); createTable(ddb, tableName); System.out.println(DASHES); System.out.println(DASHES); System.out.println("2. Loading data into the Amazon DynamoDB table."); loadData(ddb, tableName, fileName); System.out.println(DASHES); System.out.println(DASHES); System.out.println("3. Getting data from the Movie table."); getItem(ddb); System.out.println(DASHES); System.out.println(DASHES); System.out.println("4. Putting a record into the Amazon DynamoDB table."); putRecord(ddb); System.out.println(DASHES); System.out.println(DASHES); System.out.println("5. Updating a record."); updateTableItem(ddb, tableName); System.out.println(DASHES); System.out.println(DASHES); System.out.println("6. Scanning the Amazon DynamoDB table."); scanMovies(ddb, tableName); System.out.println(DASHES); System.out.println(DASHES); System.out.println("7. Querying the Movies released in 2013."); queryTable(ddb); System.out.println(DASHES); System.out.println(DASHES); System.out.println("8. Deleting the Amazon DynamoDB table."); deleteDynamoDBTable(ddb, tableName); System.out.println(DASHES); ddb.close(); } // Create a table with a Sort key. public static void createTable(DynamoDbClient ddb, String tableName) { DynamoDbWaiter dbWaiter = ddb.waiter(); ArrayList<AttributeDefinition> attributeDefinitions = new ArrayList<>(); // Define attributes. attributeDefinitions.add(AttributeDefinition.builder() .attributeName("year") .attributeType("N") .build()); attributeDefinitions.add(AttributeDefinition.builder() .attributeName("title") .attributeType("S") .build()); ArrayList<KeySchemaElement> tableKey = new ArrayList<>(); KeySchemaElement key = KeySchemaElement.builder() .attributeName("year") .keyType(KeyType.HASH) .build(); KeySchemaElement key2 = KeySchemaElement.builder() .attributeName("title") .keyType(KeyType.RANGE) .build(); // Add KeySchemaElement objects to the list. tableKey.add(key); tableKey.add(key2); CreateTableRequest request = CreateTableRequest.builder() .keySchema(tableKey) .provisionedThroughput(ProvisionedThroughput.builder() .readCapacityUnits(10L) .writeCapacityUnits(10L) .build()) .attributeDefinitions(attributeDefinitions) .tableName(tableName) .build(); try { CreateTableResponse response = ddb.createTable(request); DescribeTableRequest tableRequest = DescribeTableRequest.builder() .tableName(tableName) .build(); // Wait until the Amazon DynamoDB table is created. WaiterResponse<DescribeTableResponse> waiterResponse = dbWaiter.waitUntilTableExists(tableRequest); waiterResponse.matched().response().ifPresent(System.out::println); String newTable = response.tableDescription().tableName(); System.out.println("The " + newTable + " was successfully created."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } // Query the table. public static void queryTable(DynamoDbClient ddb) { try { DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder() .dynamoDbClient(ddb) .build(); DynamoDbTable<Movies> custTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class)); QueryConditional queryConditional = QueryConditional .keyEqualTo(Key.builder() .partitionValue(2013) .build()); // Get items in the table and write out the ID value. Iterator<Movies> results = custTable.query(queryConditional).items().iterator(); String result = ""; while (results.hasNext()) { Movies rec = results.next(); System.out.println("The title of the movie is " + rec.getTitle()); System.out.println("The movie information is " + rec.getInfo()); } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } // Scan the table. public static void scanMovies(DynamoDbClient ddb, String tableName) { System.out.println("******* Scanning all movies.\n"); try { DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder() .dynamoDbClient(ddb) .build(); DynamoDbTable<Movies> custTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class)); Iterator<Movies> results = custTable.scan().items().iterator(); while (results.hasNext()) { Movies rec = results.next(); System.out.println("The movie title is " + rec.getTitle()); System.out.println("The movie year is " + rec.getYear()); } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } // Load data into the table. public static void loadData(DynamoDbClient ddb, String tableName, String fileName) throws IOException { DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder() .dynamoDbClient(ddb) .build(); DynamoDbTable<Movies> mappedTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class)); JsonParser parser = new JsonFactory().createParser(new File(fileName)); com.fasterxml.jackson.databind.JsonNode rootNode = new ObjectMapper().readTree(parser); Iterator<JsonNode> iter = rootNode.iterator(); ObjectNode currentNode; int t = 0; while (iter.hasNext()) { // Only add 200 Movies to the table. if (t == 200) break; currentNode = (ObjectNode) iter.next(); int year = currentNode.path("year").asInt(); String title = currentNode.path("title").asText(); String info = currentNode.path("info").toString(); Movies movies = new Movies(); movies.setYear(year); movies.setTitle(title); movies.setInfo(info); // Put the data into the Amazon DynamoDB Movie table. mappedTable.putItem(movies); t++; } } // Update the record to include show only directors. public static void updateTableItem(DynamoDbClient ddb, String tableName) { HashMap<String, AttributeValue> itemKey = new HashMap<>(); itemKey.put("year", AttributeValue.builder().n("1933").build()); itemKey.put("title", AttributeValue.builder().s("King Kong").build()); HashMap<String, AttributeValueUpdate> updatedValues = new HashMap<>(); updatedValues.put("info", AttributeValueUpdate.builder() .value(AttributeValue.builder().s("{\"directors\":[\"Merian C. Cooper\",\"Ernest B. Schoedsack\"]") .build()) .action(AttributeAction.PUT) .build()); UpdateItemRequest request = UpdateItemRequest.builder() .tableName(tableName) .key(itemKey) .attributeUpdates(updatedValues) .build(); try { ddb.updateItem(request); } catch (ResourceNotFoundException e) { System.err.println(e.getMessage()); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("Item was updated!"); } public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) { DeleteTableRequest request = DeleteTableRequest.builder() .tableName(tableName) .build(); try { ddb.deleteTable(request); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println(tableName + " was successfully deleted!"); } public static void putRecord(DynamoDbClient ddb) { try { DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder() .dynamoDbClient(ddb) .build(); DynamoDbTable<Movies> table = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class)); // Populate the Table. Movies record = new Movies(); record.setYear(2020); record.setTitle("My Movie2"); record.setInfo("no info"); table.putItem(record); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("Added a new movie to the table."); } public static void getItem(DynamoDbClient ddb) { HashMap<String, AttributeValue> keyToGet = new HashMap<>(); keyToGet.put("year", AttributeValue.builder() .n("1933") .build()); keyToGet.put("title", AttributeValue.builder() .s("King Kong") .build()); GetItemRequest request = GetItemRequest.builder() .key(keyToGet) .tableName("Movies") .build(); try { Map<String, AttributeValue> returnedItem = ddb.getItem(request).item(); if (returnedItem != null) { Set<String> keys = returnedItem.keySet(); System.out.println("Amazon DynamoDB table attributes: \n"); for (String key1 : keys) { System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString()); } } else { System.out.format("No item found with the key %s!\n", "year"); } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
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For API details, see the following topics in AWS SDK for Java 2.x API Reference.
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Actions
The following code example shows how to use BatchGetItem
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- SDK for Java 2.x
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Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. shows how to get batch items using the service client.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.BatchGetItemRequest; import software.amazon.awssdk.services.dynamodb.model.BatchGetItemResponse; import software.amazon.awssdk.services.dynamodb.model.KeysAndAttributes; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Before running this Java V2 code example, set up your development environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class BatchReadItems { public static void main(String[] args){ final String usage = """ Usage: <tableName> Where: tableName - The Amazon DynamoDB table (for example, Music).\s """; String tableName = "Music"; Region region = Region.US_EAST_1; DynamoDbClient dynamoDbClient = DynamoDbClient.builder() .region(region) .build(); getBatchItems(dynamoDbClient, tableName); } public static void getBatchItems(DynamoDbClient dynamoDbClient, String tableName) { // Define the primary key values for the items you want to retrieve. Map<String, AttributeValue> key1 = new HashMap<>(); key1.put("Artist", AttributeValue.builder().s("Artist1").build()); Map<String, AttributeValue> key2 = new HashMap<>(); key2.put("Artist", AttributeValue.builder().s("Artist2").build()); // Construct the batchGetItem request. Map<String, KeysAndAttributes> requestItems = new HashMap<>(); requestItems.put(tableName, KeysAndAttributes.builder() .keys(List.of(key1, key2)) .projectionExpression("Artist, SongTitle") .build()); BatchGetItemRequest batchGetItemRequest = BatchGetItemRequest.builder() .requestItems(requestItems) .build(); // Make the batchGetItem request. BatchGetItemResponse batchGetItemResponse = dynamoDbClient.batchGetItem(batchGetItemRequest); // Extract and print the retrieved items. Map<String, List<Map<String, AttributeValue>>> responses = batchGetItemResponse.responses(); if (responses.containsKey(tableName)) { List<Map<String, AttributeValue>> musicItems = responses.get(tableName); for (Map<String, AttributeValue> item : musicItems) { System.out.println("Artist: " + item.get("Artist").s() + ", SongTitle: " + item.get("SongTitle").s()); } } else { System.out.println("No items retrieved."); } } }
shows how to get batch items using the service client and a paginator.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.BatchGetItemRequest; import software.amazon.awssdk.services.dynamodb.model.KeysAndAttributes; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; public class BatchGetItemsPaginator { public static void main(String[] args){ final String usage = """ Usage: <tableName> Where: tableName - The Amazon DynamoDB table (for example, Music).\s """; String tableName = "Music"; Region region = Region.US_EAST_1; DynamoDbClient dynamoDbClient = DynamoDbClient.builder() .region(region) .build(); getBatchItemsPaginator(dynamoDbClient, tableName) ; } public static void getBatchItemsPaginator(DynamoDbClient dynamoDbClient, String tableName) { // Define the primary key values for the items you want to retrieve. Map<String, AttributeValue> key1 = new HashMap<>(); key1.put("Artist", AttributeValue.builder().s("Artist1").build()); Map<String, AttributeValue> key2 = new HashMap<>(); key2.put("Artist", AttributeValue.builder().s("Artist2").build()); // Construct the batchGetItem request. Map<String, KeysAndAttributes> requestItems = new HashMap<>(); requestItems.put(tableName, KeysAndAttributes.builder() .keys(List.of(key1, key2)) .projectionExpression("Artist, SongTitle") .build()); BatchGetItemRequest batchGetItemRequest = BatchGetItemRequest.builder() .requestItems(requestItems) .build(); // Use batchGetItemPaginator for paginated requests. dynamoDbClient.batchGetItemPaginator(batchGetItemRequest).stream() .flatMap(response -> response.responses().getOrDefault(tableName, Collections.emptyList()).stream()) .forEach(item -> { System.out.println("Artist: " + item.get("Artist").s() + ", SongTitle: " + item.get("SongTitle").s()); }); } }
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For API details, see BatchGetItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use BatchWriteItem
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- SDK for Java 2.x
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Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Inserts many items into a table by using the service client.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.BatchWriteItemRequest; import software.amazon.awssdk.services.dynamodb.model.BatchWriteItemResponse; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.PutRequest; import software.amazon.awssdk.services.dynamodb.model.WriteRequest; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Before running this Java V2 code example, set up your development environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class BatchWriteItems { public static void main(String[] args){ final String usage = """ Usage: <tableName> Where: tableName - The Amazon DynamoDB table (for example, Music).\s """; String tableName = "Music"; Region region = Region.US_EAST_1; DynamoDbClient dynamoDbClient = DynamoDbClient.builder() .region(region) .build(); addBatchItems(dynamoDbClient, tableName); } public static void addBatchItems(DynamoDbClient dynamoDbClient, String tableName) { // Specify the updates you want to perform. List<WriteRequest> writeRequests = new ArrayList<>(); // Set item 1. Map<String, AttributeValue> item1Attributes = new HashMap<>(); item1Attributes.put("Artist", AttributeValue.builder().s("Artist1").build()); item1Attributes.put("Rating", AttributeValue.builder().s("5").build()); item1Attributes.put("Comments", AttributeValue.builder().s("Great song!").build()); item1Attributes.put("SongTitle", AttributeValue.builder().s("SongTitle1").build()); writeRequests.add(WriteRequest.builder().putRequest(PutRequest.builder().item(item1Attributes).build()).build()); // Set item 2. Map<String, AttributeValue> item2Attributes = new HashMap<>(); item2Attributes.put("Artist", AttributeValue.builder().s("Artist2").build()); item2Attributes.put("Rating", AttributeValue.builder().s("4").build()); item2Attributes.put("Comments", AttributeValue.builder().s("Nice melody.").build()); item2Attributes.put("SongTitle", AttributeValue.builder().s("SongTitle2").build()); writeRequests.add(WriteRequest.builder().putRequest(PutRequest.builder().item(item2Attributes).build()).build()); try { // Create the BatchWriteItemRequest. BatchWriteItemRequest batchWriteItemRequest = BatchWriteItemRequest.builder() .requestItems(Map.of(tableName, writeRequests)) .build(); // Execute the BatchWriteItem operation. BatchWriteItemResponse batchWriteItemResponse = dynamoDbClient.batchWriteItem(batchWriteItemRequest); // Process the response. System.out.println("Batch write successful: " + batchWriteItemResponse); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
Inserts many items into a table by using the enhanced client.
import com.example.dynamodb.Customer; import com.example.dynamodb.Music; import software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedClient; import software.amazon.awssdk.enhanced.dynamodb.DynamoDbTable; import software.amazon.awssdk.enhanced.dynamodb.Key; import software.amazon.awssdk.enhanced.dynamodb.TableSchema; import software.amazon.awssdk.enhanced.dynamodb.model.BatchWriteItemEnhancedRequest; import software.amazon.awssdk.enhanced.dynamodb.model.WriteBatch; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import java.time.Instant; import java.time.LocalDate; import java.time.LocalDateTime; import java.time.ZoneOffset; /* * Before running this code example, create an Amazon DynamoDB table named Customer with these columns: * - id - the id of the record that is the key * - custName - the customer name * - email - the email value * - registrationDate - an instant value when the item was added to the table * * Also, ensure that you have set up your development environment, including your credentials. * * For information, see this documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class EnhancedBatchWriteItems { public static void main(String[] args) { Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder() .dynamoDbClient(ddb) .build(); putBatchRecords(enhancedClient); ddb.close(); } public static void putBatchRecords(DynamoDbEnhancedClient enhancedClient) { try { DynamoDbTable<Customer> customerMappedTable = enhancedClient.table("Customer", TableSchema.fromBean(Customer.class)); DynamoDbTable<Music> musicMappedTable = enhancedClient.table("Music", TableSchema.fromBean(Music.class)); LocalDate localDate = LocalDate.parse("2020-04-07"); LocalDateTime localDateTime = localDate.atStartOfDay(); Instant instant = localDateTime.toInstant(ZoneOffset.UTC); Customer record2 = new Customer(); record2.setCustName("Fred Pink"); record2.setId("id110"); record2.setEmail("fredp@noserver.com"); record2.setRegistrationDate(instant); Customer record3 = new Customer(); record3.setCustName("Susan Pink"); record3.setId("id120"); record3.setEmail("spink@noserver.com"); record3.setRegistrationDate(instant); Customer record4 = new Customer(); record4.setCustName("Jerry orange"); record4.setId("id101"); record4.setEmail("jorange@noserver.com"); record4.setRegistrationDate(instant); BatchWriteItemEnhancedRequest batchWriteItemEnhancedRequest = BatchWriteItemEnhancedRequest .builder() .writeBatches( WriteBatch.builder(Customer.class) // add items to the Customer // table .mappedTableResource(customerMappedTable) .addPutItem(builder -> builder.item(record2)) .addPutItem(builder -> builder.item(record3)) .addPutItem(builder -> builder.item(record4)) .build(), WriteBatch.builder(Music.class) // delete an item from the Music // table .mappedTableResource(musicMappedTable) .addDeleteItem(builder -> builder.key( Key.builder().partitionValue( "Famous Band") .build())) .build()) .build(); // Add three items to the Customer table and delete one item from the Music // table. enhancedClient.batchWriteItem(batchWriteItemEnhancedRequest); System.out.println("done"); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
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For API details, see BatchWriteItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use CreateTable
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- SDK for Java 2.x
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Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. import software.amazon.awssdk.core.waiters.WaiterResponse; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeDefinition; import software.amazon.awssdk.services.dynamodb.model.CreateTableRequest; import software.amazon.awssdk.services.dynamodb.model.CreateTableResponse; import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest; import software.amazon.awssdk.services.dynamodb.model.DescribeTableResponse; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.KeySchemaElement; import software.amazon.awssdk.services.dynamodb.model.KeyType; import software.amazon.awssdk.services.dynamodb.model.ProvisionedThroughput; import software.amazon.awssdk.services.dynamodb.model.ScalarAttributeType; import software.amazon.awssdk.services.dynamodb.waiters.DynamoDbWaiter; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class CreateTable { public static void main(String[] args) { final String usage = """ Usage: <tableName> <key> Where: tableName - The Amazon DynamoDB table to create (for example, Music3). key - The key for the Amazon DynamoDB table (for example, Artist). """; if (args.length != 2) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String key = args[1]; System.out.println("Creating an Amazon DynamoDB table " + tableName + " with a simple primary key: " + key); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); String result = createTable(ddb, tableName, key); System.out.println("New table is " + result); ddb.close(); } public static String createTable(DynamoDbClient ddb, String tableName, String key) { DynamoDbWaiter dbWaiter = ddb.waiter(); CreateTableRequest request = CreateTableRequest.builder() .attributeDefinitions(AttributeDefinition.builder() .attributeName(key) .attributeType(ScalarAttributeType.S) .build()) .keySchema(KeySchemaElement.builder() .attributeName(key) .keyType(KeyType.HASH) .build()) .provisionedThroughput(ProvisionedThroughput.builder() .readCapacityUnits(10L) .writeCapacityUnits(10L) .build()) .tableName(tableName) .build(); String newTable; try { CreateTableResponse response = ddb.createTable(request); DescribeTableRequest tableRequest = DescribeTableRequest.builder() .tableName(tableName) .build(); // Wait until the Amazon DynamoDB table is created. WaiterResponse<DescribeTableResponse> waiterResponse = dbWaiter.waitUntilTableExists(tableRequest); waiterResponse.matched().response().ifPresent(System.out::println); newTable = response.tableDescription().tableName(); return newTable; } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } return ""; } }
-
For API details, see CreateTable in AWS SDK for Java 2.x API Reference.
-
The following code example shows how to use DeleteItem
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DeleteItemRequest; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import java.util.HashMap; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class DeleteItem { public static void main(String[] args) { final String usage = """ Usage: <tableName> <key> <keyval> Where: tableName - The Amazon DynamoDB table to delete the item from (for example, Music3). key - The key used in the Amazon DynamoDB table (for example, Artist).\s keyval - The key value that represents the item to delete (for example, Famous Band). """; if (args.length != 3) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String key = args[1]; String keyVal = args[2]; System.out.format("Deleting item \"%s\" from %s\n", keyVal, tableName); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); deleteDynamoDBItem(ddb, tableName, key, keyVal); ddb.close(); } public static void deleteDynamoDBItem(DynamoDbClient ddb, String tableName, String key, String keyVal) { HashMap<String, AttributeValue> keyToGet = new HashMap<>(); keyToGet.put(key, AttributeValue.builder() .s(keyVal) .build()); DeleteItemRequest deleteReq = DeleteItemRequest.builder() .tableName(tableName) .key(keyToGet) .build(); try { ddb.deleteItem(deleteReq); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
-
For API details, see DeleteItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use DeleteTable
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DeleteTableRequest; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class DeleteTable { public static void main(String[] args) { final String usage = """ Usage: <tableName> Where: tableName - The Amazon DynamoDB table to delete (for example, Music3). **Warning** This program will delete the table that you specify! """; if (args.length != 1) { System.out.println(usage); System.exit(1); } String tableName = args[0]; System.out.format("Deleting the Amazon DynamoDB table %s...\n", tableName); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); deleteDynamoDBTable(ddb, tableName); ddb.close(); } public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) { DeleteTableRequest request = DeleteTableRequest.builder() .tableName(tableName) .build(); try { ddb.deleteTable(request); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println(tableName + " was successfully deleted!"); } }
-
For API details, see DeleteTable in AWS SDK for Java 2.x API Reference.
-
The following code example shows how to use DescribeTable
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeDefinition; import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest; import software.amazon.awssdk.services.dynamodb.model.ProvisionedThroughputDescription; import software.amazon.awssdk.services.dynamodb.model.TableDescription; import java.util.List; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class DescribeTable { public static void main(String[] args) { final String usage = """ Usage: <tableName> Where: tableName - The Amazon DynamoDB table to get information about (for example, Music3). """; if (args.length != 1) { System.out.println(usage); System.exit(1); } String tableName = args[0]; System.out.format("Getting description for %s\n\n", tableName); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); describeDymamoDBTable(ddb, tableName); ddb.close(); } public static void describeDymamoDBTable(DynamoDbClient ddb, String tableName) { DescribeTableRequest request = DescribeTableRequest.builder() .tableName(tableName) .build(); try { TableDescription tableInfo = ddb.describeTable(request).table(); if (tableInfo != null) { System.out.format("Table name : %s\n", tableInfo.tableName()); System.out.format("Table ARN : %s\n", tableInfo.tableArn()); System.out.format("Status : %s\n", tableInfo.tableStatus()); System.out.format("Item count : %d\n", tableInfo.itemCount()); System.out.format("Size (bytes): %d\n", tableInfo.tableSizeBytes()); ProvisionedThroughputDescription throughputInfo = tableInfo.provisionedThroughput(); System.out.println("Throughput"); System.out.format(" Read Capacity : %d\n", throughputInfo.readCapacityUnits()); System.out.format(" Write Capacity: %d\n", throughputInfo.writeCapacityUnits()); List<AttributeDefinition> attributes = tableInfo.attributeDefinitions(); System.out.println("Attributes"); for (AttributeDefinition a : attributes) { System.out.format(" %s (%s)\n", a.attributeName(), a.attributeType()); } } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("\nDone!"); } }
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For API details, see DescribeTable in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use DescribeTimeToLive
.
- SDK for Java 2.x
-
Describe TTL configuration on an existing DynamoDB table.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DescribeTimeToLiveRequest; import software.amazon.awssdk.services.dynamodb.model.DescribeTimeToLiveResponse; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import java.util.Optional; final DescribeTimeToLiveRequest request = DescribeTimeToLiveRequest.builder() .tableName(tableName) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final DescribeTimeToLiveResponse response = ddb.describeTimeToLive(request); System.out.println(tableName + " description of time to live is " + response.toString()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.exit(0);
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For API details, see DescribeTimeToLive in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use GetItem
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Gets an item from a table by using the DynamoDbClient.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.GetItemRequest; import java.util.HashMap; import java.util.Map; import java.util.Set; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * To get an item from an Amazon DynamoDB table using the AWS SDK for Java V2, * its better practice to use the * Enhanced Client, see the EnhancedGetItem example. */ public class GetItem { public static void main(String[] args) { final String usage = """ Usage: <tableName> <key> <keyVal> Where: tableName - The Amazon DynamoDB table from which an item is retrieved (for example, Music3).\s key - The key used in the Amazon DynamoDB table (for example, Artist).\s keyval - The key value that represents the item to get (for example, Famous Band). """; if (args.length != 3) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String key = args[1]; String keyVal = args[2]; System.out.format("Retrieving item \"%s\" from \"%s\"\n", keyVal, tableName); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); getDynamoDBItem(ddb, tableName, key, keyVal); ddb.close(); } public static void getDynamoDBItem(DynamoDbClient ddb, String tableName, String key, String keyVal) { HashMap<String, AttributeValue> keyToGet = new HashMap<>(); keyToGet.put(key, AttributeValue.builder() .s(keyVal) .build()); GetItemRequest request = GetItemRequest.builder() .key(keyToGet) .tableName(tableName) .build(); try { // If there is no matching item, GetItem does not return any data. Map<String, AttributeValue> returnedItem = ddb.getItem(request).item(); if (returnedItem.isEmpty()) System.out.format("No item found with the key %s!\n", key); else { Set<String> keys = returnedItem.keySet(); System.out.println("Amazon DynamoDB table attributes: \n"); for (String key1 : keys) { System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString()); } } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
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For API details, see GetItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use ListTables
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ListTablesRequest; import software.amazon.awssdk.services.dynamodb.model.ListTablesResponse; import java.util.List; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html */ public class ListTables { public static void main(String[] args) { System.out.println("Listing your Amazon DynamoDB tables:\n"); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); listAllTables(ddb); ddb.close(); } public static void listAllTables(DynamoDbClient ddb) { boolean moreTables = true; String lastName = null; while (moreTables) { try { ListTablesResponse response = null; if (lastName == null) { ListTablesRequest request = ListTablesRequest.builder().build(); response = ddb.listTables(request); } else { ListTablesRequest request = ListTablesRequest.builder() .exclusiveStartTableName(lastName).build(); response = ddb.listTables(request); } List<String> tableNames = response.tableNames(); if (tableNames.size() > 0) { for (String curName : tableNames) { System.out.format("* %s\n", curName); } } else { System.out.println("No tables found!"); System.exit(0); } lastName = response.lastEvaluatedTableName(); if (lastName == null) { moreTables = false; } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } System.out.println("\nDone!"); } }
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For API details, see ListTables in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use PutItem
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Puts an item into a table using DynamoDbClient.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.PutItemRequest; import software.amazon.awssdk.services.dynamodb.model.PutItemResponse; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import java.util.HashMap; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * To place items into an Amazon DynamoDB table using the AWS SDK for Java V2, * its better practice to use the * Enhanced Client. See the EnhancedPutItem example. */ public class PutItem { public static void main(String[] args) { final String usage = """ Usage: <tableName> <key> <keyVal> <albumtitle> <albumtitleval> <awards> <awardsval> <Songtitle> <songtitleval> Where: tableName - The Amazon DynamoDB table in which an item is placed (for example, Music3). key - The key used in the Amazon DynamoDB table (for example, Artist). keyval - The key value that represents the item to get (for example, Famous Band). albumTitle - The Album title (for example, AlbumTitle). AlbumTitleValue - The name of the album (for example, Songs About Life ). Awards - The awards column (for example, Awards). AwardVal - The value of the awards (for example, 10). SongTitle - The song title (for example, SongTitle). SongTitleVal - The value of the song title (for example, Happy Day). **Warning** This program will place an item that you specify into a table! """; if (args.length != 9) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String key = args[1]; String keyVal = args[2]; String albumTitle = args[3]; String albumTitleValue = args[4]; String awards = args[5]; String awardVal = args[6]; String songTitle = args[7]; String songTitleVal = args[8]; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); putItemInTable(ddb, tableName, key, keyVal, albumTitle, albumTitleValue, awards, awardVal, songTitle, songTitleVal); System.out.println("Done!"); ddb.close(); } public static void putItemInTable(DynamoDbClient ddb, String tableName, String key, String keyVal, String albumTitle, String albumTitleValue, String awards, String awardVal, String songTitle, String songTitleVal) { HashMap<String, AttributeValue> itemValues = new HashMap<>(); itemValues.put(key, AttributeValue.builder().s(keyVal).build()); itemValues.put(songTitle, AttributeValue.builder().s(songTitleVal).build()); itemValues.put(albumTitle, AttributeValue.builder().s(albumTitleValue).build()); itemValues.put(awards, AttributeValue.builder().s(awardVal).build()); PutItemRequest request = PutItemRequest.builder() .tableName(tableName) .item(itemValues) .build(); try { PutItemResponse response = ddb.putItem(request); System.out.println(tableName + " was successfully updated. The request id is " + response.responseMetadata().requestId()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.err.println("Be sure that it exists and that you've typed its name correctly!"); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
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For API details, see PutItem in AWS SDK for Java 2.x API Reference.
-
The following code example shows how to use Query
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Queries a table by using DynamoDbClient.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.QueryRequest; import software.amazon.awssdk.services.dynamodb.model.QueryResponse; import java.util.HashMap; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * To query items from an Amazon DynamoDB table using the AWS SDK for Java V2, * its better practice to use the * Enhanced Client. See the EnhancedQueryRecords example. */ public class Query { public static void main(String[] args) { final String usage = """ Usage: <tableName> <partitionKeyName> <partitionKeyVal> Where: tableName - The Amazon DynamoDB table to put the item in (for example, Music3). partitionKeyName - The partition key name of the Amazon DynamoDB table (for example, Artist). partitionKeyVal - The value of the partition key that should match (for example, Famous Band). """; if (args.length != 3) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String partitionKeyName = args[1]; String partitionKeyVal = args[2]; // For more information about an alias, see: // https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.ExpressionAttributeNames.html String partitionAlias = "#a"; System.out.format("Querying %s", tableName); System.out.println(""); Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); int count = queryTable(ddb, tableName, partitionKeyName, partitionKeyVal, partitionAlias); System.out.println("There were " + count + " record(s) returned"); ddb.close(); } public static int queryTable(DynamoDbClient ddb, String tableName, String partitionKeyName, String partitionKeyVal, String partitionAlias) { // Set up an alias for the partition key name in case it's a reserved word. HashMap<String, String> attrNameAlias = new HashMap<String, String>(); attrNameAlias.put(partitionAlias, partitionKeyName); // Set up mapping of the partition name with the value. HashMap<String, AttributeValue> attrValues = new HashMap<>(); attrValues.put(":" + partitionKeyName, AttributeValue.builder() .s(partitionKeyVal) .build()); QueryRequest queryReq = QueryRequest.builder() .tableName(tableName) .keyConditionExpression(partitionAlias + " = :" + partitionKeyName) .expressionAttributeNames(attrNameAlias) .expressionAttributeValues(attrValues) .build(); try { QueryResponse response = ddb.query(queryReq); return response.count(); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } return -1; } }
Queries a table by using
DynamoDbClient
and a secondary index.import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.QueryRequest; import software.amazon.awssdk.services.dynamodb.model.QueryResponse; import java.util.HashMap; import java.util.Map; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * Create the Movies table by running the Scenario example and loading the Movie * data from the JSON file. Next create a secondary * index for the Movies table that uses only the year column. Name the index * **year-index**. For more information, see: * * https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html */ public class QueryItemsUsingIndex { public static void main(String[] args) { String tableName = "Movies"; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); queryIndex(ddb, tableName); ddb.close(); } public static void queryIndex(DynamoDbClient ddb, String tableName) { try { Map<String, String> expressionAttributesNames = new HashMap<>(); expressionAttributesNames.put("#year", "year"); Map<String, AttributeValue> expressionAttributeValues = new HashMap<>(); expressionAttributeValues.put(":yearValue", AttributeValue.builder().n("2013").build()); QueryRequest request = QueryRequest.builder() .tableName(tableName) .indexName("year-index") .keyConditionExpression("#year = :yearValue") .expressionAttributeNames(expressionAttributesNames) .expressionAttributeValues(expressionAttributeValues) .build(); System.out.println("=== Movie Titles ==="); QueryResponse response = ddb.query(request); response.items() .forEach(movie -> System.out.println(movie.get("title").s())); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } }
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For API details, see Query in AWS SDK for Java 2.x API Reference.
-
The following code example shows how to use Scan
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Scans an Amazon DynamoDB table using DynamoDbClient.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ScanRequest; import software.amazon.awssdk.services.dynamodb.model.ScanResponse; import java.util.Map; import java.util.Set; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * To scan items from an Amazon DynamoDB table using the AWS SDK for Java V2, * its better practice to use the * Enhanced Client, See the EnhancedScanRecords example. */ public class DynamoDBScanItems { public static void main(String[] args) { final String usage = """ Usage: <tableName> Where: tableName - The Amazon DynamoDB table to get information from (for example, Music3). """; if (args.length != 1) { System.out.println(usage); System.exit(1); } String tableName = args[0]; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); scanItems(ddb, tableName); ddb.close(); } public static void scanItems(DynamoDbClient ddb, String tableName) { try { ScanRequest scanRequest = ScanRequest.builder() .tableName(tableName) .build(); ScanResponse response = ddb.scan(scanRequest); for (Map<String, AttributeValue> item : response.items()) { Set<String> keys = item.keySet(); for (String key : keys) { System.out.println("The key name is " + key + "\n"); System.out.println("The value is " + item.get(key).s()); } } } catch (DynamoDbException e) { e.printStackTrace(); System.exit(1); } } }
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For API details, see Scan in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use UpdateItem
.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. Updates an item in a table using DynamoDbClient.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.AttributeAction; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.AttributeValueUpdate; import software.amazon.awssdk.services.dynamodb.model.UpdateItemRequest; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import java.util.HashMap; /** * Before running this Java V2 code example, set up your development * environment, including your credentials. * * For more information, see the following documentation topic: * * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html * * To update an Amazon DynamoDB table using the AWS SDK for Java V2, its better * practice to use the * Enhanced Client, See the EnhancedModifyItem example. */ public class UpdateItem { public static void main(String[] args) { final String usage = """ Usage: <tableName> <key> <keyVal> <name> <updateVal> Where: tableName - The Amazon DynamoDB table (for example, Music3). key - The name of the key in the table (for example, Artist). keyVal - The value of the key (for example, Famous Band). name - The name of the column where the value is updated (for example, Awards). updateVal - The value used to update an item (for example, 14). Example: UpdateItem Music3 Artist Famous Band Awards 14 """; if (args.length != 5) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String key = args[1]; String keyVal = args[2]; String name = args[3]; String updateVal = args[4]; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); updateTableItem(ddb, tableName, key, keyVal, name, updateVal); ddb.close(); } public static void updateTableItem(DynamoDbClient ddb, String tableName, String key, String keyVal, String name, String updateVal) { HashMap<String, AttributeValue> itemKey = new HashMap<>(); itemKey.put(key, AttributeValue.builder() .s(keyVal) .build()); HashMap<String, AttributeValueUpdate> updatedValues = new HashMap<>(); updatedValues.put(name, AttributeValueUpdate.builder() .value(AttributeValue.builder().s(updateVal).build()) .action(AttributeAction.PUT) .build()); UpdateItemRequest request = UpdateItemRequest.builder() .tableName(tableName) .key(itemKey) .attributeUpdates(updatedValues) .build(); try { ddb.updateItem(request); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("The Amazon DynamoDB table was updated!"); } }
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For API details, see UpdateItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to use UpdateTimeToLive
.
- SDK for Java 2.x
-
Enable TTL on an existing DynamoDB table.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import software.amazon.awssdk.services.dynamodb.model.TimeToLiveSpecification; import software.amazon.awssdk.services.dynamodb.model.UpdateTimeToLiveRequest; import software.amazon.awssdk.services.dynamodb.model.UpdateTimeToLiveResponse; import java.util.Optional; final TimeToLiveSpecification ttlSpecification = TimeToLiveSpecification.builder() .attributeName(ttlAttributeName) .enabled(true) .build(); final UpdateTimeToLiveRequest request = UpdateTimeToLiveRequest.builder() .tableName(tableName) .timeToLiveSpecification(ttlSpecification) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final UpdateTimeToLiveResponse response = ddb.updateTimeToLive(request); System.out.println(tableName + " had its TTL successfully updated. The request id is " + response.responseMetadata().requestId()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("Done!");
Disable TTL on an existing DynamoDB table.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import software.amazon.awssdk.services.dynamodb.model.TimeToLiveSpecification; import software.amazon.awssdk.services.dynamodb.model.UpdateTimeToLiveRequest; import software.amazon.awssdk.services.dynamodb.model.UpdateTimeToLiveResponse; import java.util.Optional; final Region region = Optional.ofNullable(args[2]).isEmpty() ? Region.US_EAST_1 : Region.of(args[2]); final TimeToLiveSpecification ttlSpecification = TimeToLiveSpecification.builder() .attributeName(ttlAttributeName) .enabled(false) .build(); final UpdateTimeToLiveRequest request = UpdateTimeToLiveRequest.builder() .tableName(tableName) .timeToLiveSpecification(ttlSpecification) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final UpdateTimeToLiveResponse response = ddb.updateTimeToLive(request); System.out.println(tableName + " had its TTL successfully updated. The request id is " + response.responseMetadata().requestId()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("Done!");
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For API details, see UpdateTimeToLive in AWS SDK for Java 2.x API Reference.
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Scenarios
The following code example shows how to build an application that submits data to an Amazon DynamoDB table and notifies you when a user updates the table.
- SDK for Java 2.x
-
Shows how to create a dynamic web application that submits data using the Amazon DynamoDB Java API and sends a text message using the Amazon Simple Notification Service Java API.
For complete source code and instructions on how to set up and run, see the full example on GitHub
. Services used in this example
DynamoDB
Amazon SNS
The following code example shows how to conditionally update an item's TTL.
- SDK for Java 2.x
-
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 package com.amazon.samplelib.ttl; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import software.amazon.awssdk.services.dynamodb.model.UpdateItemRequest; import software.amazon.awssdk.services.dynamodb.model.UpdateItemResponse; import software.amazon.awssdk.utils.ImmutableMap; import java.util.Map; import java.util.Optional; public class UpdateTTLConditional { public static void main(String[] args) { final String usage = """ Usage: <tableName> <primaryKey> <sortKey> <newTtlAttribute> <region> Where: tableName - The Amazon DynamoDB table being queried. primaryKey - The name of the primary key. Also known as the hash or partition key. sortKey - The name of the sort key. Also known as the range attribute. newTtlAttribute - New attribute name (as part of the update command) region (optional) - The AWS region that the Amazon DynamoDB table is located in. (Default: us-east-1) """; // Optional "region" parameter - if args list length is NOT 3 or 4, short-circuit exit. if (!(args.length == 4 || args.length == 5)) { System.out.println(usage); System.exit(1); } final String tableName = args[0]; final String primaryKey = args[1]; final String sortKey = args[2]; final String newTtlAttribute = args[3]; Region region = Optional.ofNullable(args[4]).isEmpty() ? Region.US_EAST_1 : Region.of(args[4]); // Get current time in epoch second format final long currentTime = System.currentTimeMillis() / 1000; // Calculate expiration time 90 days from now in epoch second format final long expireDate = currentTime + (90 * 24 * 60 * 60); // An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them. final String updateExpression = "SET newTtlAttribute = :val1"; // A condition that must be satisfied in order for a conditional update to succeed. final String conditionExpression = "expireAt > :val2"; final ImmutableMap<String, AttributeValue> keyMap = ImmutableMap.of("primaryKey", AttributeValue.fromS(primaryKey), "sortKey", AttributeValue.fromS(sortKey)); final Map<String, AttributeValue> expressionAttributeValues = ImmutableMap.of( ":val1", AttributeValue.builder().s(newTtlAttribute).build(), ":val2", AttributeValue.builder().s(String.valueOf(expireDate)).build() ); final UpdateItemRequest request = UpdateItemRequest.builder() .tableName(tableName) .key(keyMap) .updateExpression(updateExpression) .conditionExpression(conditionExpression) .expressionAttributeValues(expressionAttributeValues) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final UpdateItemResponse response = ddb.updateItem(request); System.out.println(tableName + " UpdateItem operation with conditional TTL successful. Request id is " + response.responseMetadata().requestId()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.exit(0); } }
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For API details, see UpdateItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to create a serverless application that lets users manage photos using labels.
- SDK for Java 2.x
-
Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.
For complete source code and instructions on how to set up and run, see the full example on GitHub
. For a deep dive into the origin of this example see the post on AWS Community
. Services used in this example
API Gateway
DynamoDB
Lambda
Amazon Rekognition
Amazon S3
Amazon SNS
The following code example shows how to create a web application that tracks work items in an Amazon DynamoDB table and uses Amazon Simple Email Service (Amazon SES) to send reports.
- SDK for Java 2.x
-
Shows how to use the Amazon DynamoDB API to create a dynamic web application that tracks DynamoDB work data.
For complete source code and instructions on how to set up and run, see the full example on GitHub
. Services used in this example
DynamoDB
Amazon SES
The following code example shows how to create an item with TTL.
- SDK for Java 2.x
-
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 package com.amazon.samplelib.ttl; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.PutItemRequest; import software.amazon.awssdk.services.dynamodb.model.PutItemResponse; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import software.amazon.awssdk.utils.ImmutableMap; import java.io.Serializable; import java.util.Map; import java.util.Optional; public class CreateTTL { public static void main(String[] args) { final String usage = """ Usage: <tableName> <primaryKey> <sortKey> <region> Where: tableName - The Amazon DynamoDB table being queried. primaryKey - The name of the primary key. Also known as the hash or partition key. sortKey - The name of the sort key. Also known as the range attribute. region (optional) - The AWS region that the Amazon DynamoDB table is located in. (Default: us-east-1) """; // Optional "region" parameter - if args list length is NOT 3 or 4, short-circuit exit. if (!(args.length == 3 || args.length == 4)) { System.out.println(usage); System.exit(1); } String tableName = args[0]; String primaryKey = args[1]; String sortKey = args[2]; Region region = Optional.ofNullable(args[3]).isEmpty() ? Region.US_EAST_1 : Region.of(args[3]); // Get current time in epoch second format final long createDate = System.currentTimeMillis() / 1000; // Calculate expiration time 90 days from now in epoch second format final long expireDate = createDate + (90 * 24 * 60 * 60); final ImmutableMap<String, ? extends Serializable> itemMap = ImmutableMap.of("primaryKey", primaryKey, "sortKey", sortKey, "creationDate", createDate, "expireAt", expireDate); final PutItemRequest request = PutItemRequest.builder() .tableName(tableName) .item((Map<String, AttributeValue>) itemMap) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final PutItemResponse response = ddb.putItem(request); System.out.println(tableName + " PutItem operation with TTL successful. Request id is " + response.responseMetadata().requestId()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.exit(0); } }
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For API details, see PutItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to build an app that uses Amazon Rekognition to detect Personal Protective Equipment (PPE) in images.
- SDK for Java 2.x
-
Shows how to create an AWS Lambda function that detects images with Personal Protective Equipment.
For complete source code and instructions on how to set up and run, see the full example on GitHub
. Services used in this example
DynamoDB
Amazon Rekognition
Amazon S3
Amazon SES
The following code example shows how to configure an application's use of DynamoDB to monitor performance.
- SDK for Java 2.x
-
This example shows how to configure a Java application to monitor the performance of DynamoDB. The application sends metric data to CloudWatch where you can monitor the performance.
For complete source code and instructions on how to set up and run, see the full example on GitHub
. Services used in this example
CloudWatch
DynamoDB
The following code example shows how to:
Get a batch of items by running multiple SELECT statements.
Add a batch of items by running multiple INSERT statements.
Update a batch of items by running multiple UPDATE statements.
Delete a batch of items by running multiple DELETE statements.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. public class ScenarioPartiQLBatch { public static void main(String[] args) throws IOException { String tableName = "MoviesPartiQBatch"; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); System.out.println("******* Creating an Amazon DynamoDB table named " + tableName + " with a key named year and a sort key named title."); createTable(ddb, tableName); System.out.println("******* Adding multiple records into the " + tableName + " table using a batch command."); putRecordBatch(ddb); System.out.println("******* Updating multiple records using a batch command."); updateTableItemBatch(ddb); System.out.println("******* Deleting multiple records using a batch command."); deleteItemBatch(ddb); System.out.println("******* Deleting the Amazon DynamoDB table."); deleteDynamoDBTable(ddb, tableName); ddb.close(); } public static void createTable(DynamoDbClient ddb, String tableName) { DynamoDbWaiter dbWaiter = ddb.waiter(); ArrayList<AttributeDefinition> attributeDefinitions = new ArrayList<>(); // Define attributes. attributeDefinitions.add(AttributeDefinition.builder() .attributeName("year") .attributeType("N") .build()); attributeDefinitions.add(AttributeDefinition.builder() .attributeName("title") .attributeType("S") .build()); ArrayList<KeySchemaElement> tableKey = new ArrayList<>(); KeySchemaElement key = KeySchemaElement.builder() .attributeName("year") .keyType(KeyType.HASH) .build(); KeySchemaElement key2 = KeySchemaElement.builder() .attributeName("title") .keyType(KeyType.RANGE) // Sort .build(); // Add KeySchemaElement objects to the list. tableKey.add(key); tableKey.add(key2); CreateTableRequest request = CreateTableRequest.builder() .keySchema(tableKey) .provisionedThroughput(ProvisionedThroughput.builder() .readCapacityUnits(new Long(10)) .writeCapacityUnits(new Long(10)) .build()) .attributeDefinitions(attributeDefinitions) .tableName(tableName) .build(); try { CreateTableResponse response = ddb.createTable(request); DescribeTableRequest tableRequest = DescribeTableRequest.builder() .tableName(tableName) .build(); // Wait until the Amazon DynamoDB table is created. WaiterResponse<DescribeTableResponse> waiterResponse = dbWaiter .waitUntilTableExists(tableRequest); waiterResponse.matched().response().ifPresent(System.out::println); String newTable = response.tableDescription().tableName(); System.out.println("The " + newTable + " was successfully created."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } public static void putRecordBatch(DynamoDbClient ddb) { String sqlStatement = "INSERT INTO MoviesPartiQBatch VALUE {'year':?, 'title' : ?, 'info' : ?}"; try { // Create three movies to add to the Amazon DynamoDB table. // Set data for Movie 1. List<AttributeValue> parameters = new ArrayList<>(); AttributeValue att1 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue att2 = AttributeValue.builder() .s("My Movie 1") .build(); AttributeValue att3 = AttributeValue.builder() .s("No Information") .build(); parameters.add(att1); parameters.add(att2); parameters.add(att3); BatchStatementRequest statementRequestMovie1 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parameters) .build(); // Set data for Movie 2. List<AttributeValue> parametersMovie2 = new ArrayList<>(); AttributeValue attMovie2 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue attMovie2A = AttributeValue.builder() .s("My Movie 2") .build(); AttributeValue attMovie2B = AttributeValue.builder() .s("No Information") .build(); parametersMovie2.add(attMovie2); parametersMovie2.add(attMovie2A); parametersMovie2.add(attMovie2B); BatchStatementRequest statementRequestMovie2 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersMovie2) .build(); // Set data for Movie 3. List<AttributeValue> parametersMovie3 = new ArrayList<>(); AttributeValue attMovie3 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue attMovie3A = AttributeValue.builder() .s("My Movie 3") .build(); AttributeValue attMovie3B = AttributeValue.builder() .s("No Information") .build(); parametersMovie3.add(attMovie3); parametersMovie3.add(attMovie3A); parametersMovie3.add(attMovie3B); BatchStatementRequest statementRequestMovie3 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersMovie3) .build(); // Add all three movies to the list. List<BatchStatementRequest> myBatchStatementList = new ArrayList<>(); myBatchStatementList.add(statementRequestMovie1); myBatchStatementList.add(statementRequestMovie2); myBatchStatementList.add(statementRequestMovie3); BatchExecuteStatementRequest batchRequest = BatchExecuteStatementRequest.builder() .statements(myBatchStatementList) .build(); BatchExecuteStatementResponse response = ddb.batchExecuteStatement(batchRequest); System.out.println("ExecuteStatement successful: " + response.toString()); System.out.println("Added new movies using a batch command."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } public static void updateTableItemBatch(DynamoDbClient ddb) { String sqlStatement = "UPDATE MoviesPartiQBatch SET info = 'directors\":[\"Merian C. Cooper\",\"Ernest B. Schoedsack' where year=? and title=?"; List<AttributeValue> parametersRec1 = new ArrayList<>(); // Update three records. AttributeValue att1 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue att2 = AttributeValue.builder() .s("My Movie 1") .build(); parametersRec1.add(att1); parametersRec1.add(att2); BatchStatementRequest statementRequestRec1 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersRec1) .build(); // Update record 2. List<AttributeValue> parametersRec2 = new ArrayList<>(); AttributeValue attRec2 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue attRec2a = AttributeValue.builder() .s("My Movie 2") .build(); parametersRec2.add(attRec2); parametersRec2.add(attRec2a); BatchStatementRequest statementRequestRec2 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersRec2) .build(); // Update record 3. List<AttributeValue> parametersRec3 = new ArrayList<>(); AttributeValue attRec3 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue attRec3a = AttributeValue.builder() .s("My Movie 3") .build(); parametersRec3.add(attRec3); parametersRec3.add(attRec3a); BatchStatementRequest statementRequestRec3 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersRec3) .build(); // Add all three movies to the list. List<BatchStatementRequest> myBatchStatementList = new ArrayList<>(); myBatchStatementList.add(statementRequestRec1); myBatchStatementList.add(statementRequestRec2); myBatchStatementList.add(statementRequestRec3); BatchExecuteStatementRequest batchRequest = BatchExecuteStatementRequest.builder() .statements(myBatchStatementList) .build(); try { BatchExecuteStatementResponse response = ddb.batchExecuteStatement(batchRequest); System.out.println("ExecuteStatement successful: " + response.toString()); System.out.println("Updated three movies using a batch command."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("Item was updated!"); } public static void deleteItemBatch(DynamoDbClient ddb) { String sqlStatement = "DELETE FROM MoviesPartiQBatch WHERE year = ? and title=?"; List<AttributeValue> parametersRec1 = new ArrayList<>(); // Specify three records to delete. AttributeValue att1 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue att2 = AttributeValue.builder() .s("My Movie 1") .build(); parametersRec1.add(att1); parametersRec1.add(att2); BatchStatementRequest statementRequestRec1 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersRec1) .build(); // Specify record 2. List<AttributeValue> parametersRec2 = new ArrayList<>(); AttributeValue attRec2 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue attRec2a = AttributeValue.builder() .s("My Movie 2") .build(); parametersRec2.add(attRec2); parametersRec2.add(attRec2a); BatchStatementRequest statementRequestRec2 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersRec2) .build(); // Specify record 3. List<AttributeValue> parametersRec3 = new ArrayList<>(); AttributeValue attRec3 = AttributeValue.builder() .n(String.valueOf("2022")) .build(); AttributeValue attRec3a = AttributeValue.builder() .s("My Movie 3") .build(); parametersRec3.add(attRec3); parametersRec3.add(attRec3a); BatchStatementRequest statementRequestRec3 = BatchStatementRequest.builder() .statement(sqlStatement) .parameters(parametersRec3) .build(); // Add all three movies to the list. List<BatchStatementRequest> myBatchStatementList = new ArrayList<>(); myBatchStatementList.add(statementRequestRec1); myBatchStatementList.add(statementRequestRec2); myBatchStatementList.add(statementRequestRec3); BatchExecuteStatementRequest batchRequest = BatchExecuteStatementRequest.builder() .statements(myBatchStatementList) .build(); try { ddb.batchExecuteStatement(batchRequest); System.out.println("Deleted three movies using a batch command."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) { DeleteTableRequest request = DeleteTableRequest.builder() .tableName(tableName) .build(); try { ddb.deleteTable(request); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println(tableName + " was successfully deleted!"); } private static ExecuteStatementResponse executeStatementRequest(DynamoDbClient ddb, String statement, List<AttributeValue> parameters) { ExecuteStatementRequest request = ExecuteStatementRequest.builder() .statement(statement) .parameters(parameters) .build(); return ddb.executeStatement(request); } }
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For API details, see BatchExecuteStatement in AWS SDK for Java 2.x API Reference.
-
The following code example shows how to:
Get an item by running a SELECT statement.
Add an item by running an INSERT statement.
Update an item by running an UPDATE statement.
Delete an item by running a DELETE statement.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository
. public class ScenarioPartiQ { public static void main(String[] args) throws IOException { final String usage = """ Usage: <fileName> Where: fileName - The path to the moviedata.json file that you can download from the Amazon DynamoDB Developer Guide. """; if (args.length != 1) { System.out.println(usage); System.exit(1); } String fileName = args[0]; String tableName = "MoviesPartiQ"; Region region = Region.US_EAST_1; DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build(); System.out.println( "******* Creating an Amazon DynamoDB table named MoviesPartiQ with a key named year and a sort key named title."); createTable(ddb, tableName); System.out.println("******* Loading data into the MoviesPartiQ table."); loadData(ddb, fileName); System.out.println("******* Getting data from the MoviesPartiQ table."); getItem(ddb); System.out.println("******* Putting a record into the MoviesPartiQ table."); putRecord(ddb); System.out.println("******* Updating a record."); updateTableItem(ddb); System.out.println("******* Querying the movies released in 2013."); queryTable(ddb); System.out.println("******* Deleting the Amazon DynamoDB table."); deleteDynamoDBTable(ddb, tableName); ddb.close(); } public static void createTable(DynamoDbClient ddb, String tableName) { DynamoDbWaiter dbWaiter = ddb.waiter(); ArrayList<AttributeDefinition> attributeDefinitions = new ArrayList<>(); // Define attributes. attributeDefinitions.add(AttributeDefinition.builder() .attributeName("year") .attributeType("N") .build()); attributeDefinitions.add(AttributeDefinition.builder() .attributeName("title") .attributeType("S") .build()); ArrayList<KeySchemaElement> tableKey = new ArrayList<>(); KeySchemaElement key = KeySchemaElement.builder() .attributeName("year") .keyType(KeyType.HASH) .build(); KeySchemaElement key2 = KeySchemaElement.builder() .attributeName("title") .keyType(KeyType.RANGE) // Sort .build(); // Add KeySchemaElement objects to the list. tableKey.add(key); tableKey.add(key2); CreateTableRequest request = CreateTableRequest.builder() .keySchema(tableKey) .provisionedThroughput(ProvisionedThroughput.builder() .readCapacityUnits(new Long(10)) .writeCapacityUnits(new Long(10)) .build()) .attributeDefinitions(attributeDefinitions) .tableName(tableName) .build(); try { CreateTableResponse response = ddb.createTable(request); DescribeTableRequest tableRequest = DescribeTableRequest.builder() .tableName(tableName) .build(); // Wait until the Amazon DynamoDB table is created. WaiterResponse<DescribeTableResponse> waiterResponse = dbWaiter.waitUntilTableExists(tableRequest); waiterResponse.matched().response().ifPresent(System.out::println); String newTable = response.tableDescription().tableName(); System.out.println("The " + newTable + " was successfully created."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } // Load data into the table. public static void loadData(DynamoDbClient ddb, String fileName) throws IOException { String sqlStatement = "INSERT INTO MoviesPartiQ VALUE {'year':?, 'title' : ?, 'info' : ?}"; JsonParser parser = new JsonFactory().createParser(new File(fileName)); com.fasterxml.jackson.databind.JsonNode rootNode = new ObjectMapper().readTree(parser); Iterator<JsonNode> iter = rootNode.iterator(); ObjectNode currentNode; int t = 0; List<AttributeValue> parameters = new ArrayList<>(); while (iter.hasNext()) { // Add 200 movies to the table. if (t == 200) break; currentNode = (ObjectNode) iter.next(); int year = currentNode.path("year").asInt(); String title = currentNode.path("title").asText(); String info = currentNode.path("info").toString(); AttributeValue att1 = AttributeValue.builder() .n(String.valueOf(year)) .build(); AttributeValue att2 = AttributeValue.builder() .s(title) .build(); AttributeValue att3 = AttributeValue.builder() .s(info) .build(); parameters.add(att1); parameters.add(att2); parameters.add(att3); // Insert the movie into the Amazon DynamoDB table. executeStatementRequest(ddb, sqlStatement, parameters); System.out.println("Added Movie " + title); parameters.remove(att1); parameters.remove(att2); parameters.remove(att3); t++; } } public static void getItem(DynamoDbClient ddb) { String sqlStatement = "SELECT * FROM MoviesPartiQ where year=? and title=?"; List<AttributeValue> parameters = new ArrayList<>(); AttributeValue att1 = AttributeValue.builder() .n("2012") .build(); AttributeValue att2 = AttributeValue.builder() .s("The Perks of Being a Wallflower") .build(); parameters.add(att1); parameters.add(att2); try { ExecuteStatementResponse response = executeStatementRequest(ddb, sqlStatement, parameters); System.out.println("ExecuteStatement successful: " + response.toString()); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } public static void putRecord(DynamoDbClient ddb) { String sqlStatement = "INSERT INTO MoviesPartiQ VALUE {'year':?, 'title' : ?, 'info' : ?}"; try { List<AttributeValue> parameters = new ArrayList<>(); AttributeValue att1 = AttributeValue.builder() .n(String.valueOf("2020")) .build(); AttributeValue att2 = AttributeValue.builder() .s("My Movie") .build(); AttributeValue att3 = AttributeValue.builder() .s("No Information") .build(); parameters.add(att1); parameters.add(att2); parameters.add(att3); executeStatementRequest(ddb, sqlStatement, parameters); System.out.println("Added new movie."); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } public static void updateTableItem(DynamoDbClient ddb) { String sqlStatement = "UPDATE MoviesPartiQ SET info = 'directors\":[\"Merian C. Cooper\",\"Ernest B. Schoedsack' where year=? and title=?"; List<AttributeValue> parameters = new ArrayList<>(); AttributeValue att1 = AttributeValue.builder() .n(String.valueOf("2013")) .build(); AttributeValue att2 = AttributeValue.builder() .s("The East") .build(); parameters.add(att1); parameters.add(att2); try { executeStatementRequest(ddb, sqlStatement, parameters); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("Item was updated!"); } // Query the table where the year is 2013. public static void queryTable(DynamoDbClient ddb) { String sqlStatement = "SELECT * FROM MoviesPartiQ where year = ? ORDER BY year"; try { List<AttributeValue> parameters = new ArrayList<>(); AttributeValue att1 = AttributeValue.builder() .n(String.valueOf("2013")) .build(); parameters.add(att1); // Get items in the table and write out the ID value. ExecuteStatementResponse response = executeStatementRequest(ddb, sqlStatement, parameters); System.out.println("ExecuteStatement successful: " + response.toString()); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } } public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) { DeleteTableRequest request = DeleteTableRequest.builder() .tableName(tableName) .build(); try { ddb.deleteTable(request); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println(tableName + " was successfully deleted!"); } private static ExecuteStatementResponse executeStatementRequest(DynamoDbClient ddb, String statement, List<AttributeValue> parameters) { ExecuteStatementRequest request = ExecuteStatementRequest.builder() .statement(statement) .parameters(parameters) .build(); return ddb.executeStatement(request); } private static void processResults(ExecuteStatementResponse executeStatementResult) { System.out.println("ExecuteStatement successful: " + executeStatementResult.toString()); } }
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For API details, see ExecuteStatement in AWS SDK for Java 2.x API Reference.
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The following code example shows how to query for TTL items.
- SDK for Java 2.x
-
Query Filtered Expression to gather TTL items in a DynamoDB table.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.QueryRequest; import software.amazon.awssdk.services.dynamodb.model.QueryResponse; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import software.amazon.awssdk.utils.ImmutableMap; import java.util.Map; import java.util.Optional; // Get current time in epoch second format (comparing against expiry attribute) final long currentTime = System.currentTimeMillis() / 1000; // A string that contains conditions that DynamoDB applies after the Query operation, but before the data is returned to you. final String keyConditionExpression = "#pk = :pk"; // The condition that specifies the key values for items to be retrieved by the Query action. final String filterExpression = "#ea > :ea"; final Map<String, String> expressionAttributeNames = ImmutableMap.of( "#pk", "primaryKey", "#ea", "expireAt"); final Map<String, AttributeValue> expressionAttributeValues = ImmutableMap.of( ":pk", AttributeValue.builder().s(primaryKey).build(), ":ea", AttributeValue.builder().s(String.valueOf(currentTime)).build() ); final QueryRequest request = QueryRequest.builder() .tableName(tableName) .keyConditionExpression(keyConditionExpression) .filterExpression(filterExpression) .expressionAttributeNames(expressionAttributeNames) .expressionAttributeValues(expressionAttributeValues) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final QueryResponse response = ddb.query(request); System.out.println(tableName + " Query operation with TTL successful. Request id is " + response.responseMetadata().requestId()); // Print the items that are not expired for (Map<String, AttributeValue> item : response.items()) { System.out.println(item.toString()); } } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.exit(0);
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For API details, see Query in AWS SDK for Java 2.x API Reference.
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The following code example shows how to update an item's TTL.
- SDK for Java 2.x
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Update TTL on an existing DynamoDB item in a table.
import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.dynamodb.DynamoDbClient; import software.amazon.awssdk.services.dynamodb.model.AttributeValue; import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import software.amazon.awssdk.services.dynamodb.model.UpdateItemRequest; import software.amazon.awssdk.services.dynamodb.model.UpdateItemResponse; import software.amazon.awssdk.utils.ImmutableMap; import java.util.Map; import java.util.Optional; // Get current time in epoch second format final long currentTime = System.currentTimeMillis() / 1000; // Calculate expiration time 90 days from now in epoch second format final long expireDate = currentTime + (90 * 24 * 60 * 60); // An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them. final String updateExpression = "SET updatedAt=:c, expireAt=:e"; final ImmutableMap<String, AttributeValue> keyMap = ImmutableMap.of("primaryKey", AttributeValue.fromS(primaryKey), "sortKey", AttributeValue.fromS(sortKey)); final Map<String, AttributeValue> expressionAttributeValues = ImmutableMap.of( ":c", AttributeValue.builder().s(String.valueOf(currentTime)).build(), ":e", AttributeValue.builder().s(String.valueOf(expireDate)).build() ); final UpdateItemRequest request = UpdateItemRequest.builder() .tableName(tableName) .key(keyMap) .updateExpression(updateExpression) .expressionAttributeValues(expressionAttributeValues) .build(); try (DynamoDbClient ddb = DynamoDbClient.builder() .region(region) .build()) { final UpdateItemResponse response = ddb.updateItem(request); System.out.println(tableName + " UpdateItem operation with TTL successful. Request id is " + response.responseMetadata().requestId()); } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); System.exit(1); } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.exit(0);
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For API details, see UpdateItem in AWS SDK for Java 2.x API Reference.
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The following code example shows how to create an AWS Step Functions state machine that invokes AWS Lambda functions in sequence.
- SDK for Java 2.x
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Shows how to create an AWS serverless workflow by using AWS Step Functions and the AWS SDK for Java 2.x. Each workflow step is implemented using an AWS Lambda function.
For complete source code and instructions on how to set up and run, see the full example on GitHub
. Services used in this example
DynamoDB
Lambda
Amazon SES
Step Functions
Serverless examples
The following code example shows how to implement a Lambda function that receives an event triggered by receiving records from a DynamoDB stream. The function retrieves the DynamoDB payload and logs the record contents.
- SDK for Java 2.x
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Note
There's more on GitHub. Find the complete example and learn how to set up and run in the Serverless examples
repository. Consuming a DynamoDB event with Lambda using Java.
import com.amazonaws.services.lambda.runtime.Context; import com.amazonaws.services.lambda.runtime.RequestHandler; import com.amazonaws.services.lambda.runtime.events.DynamodbEvent; import com.amazonaws.services.lambda.runtime.events.DynamodbEvent.DynamodbStreamRecord; import com.google.gson.Gson; import com.google.gson.GsonBuilder; public class example implements RequestHandler<DynamodbEvent, Void> { private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create(); @Override public Void handleRequest(DynamodbEvent event, Context context) { System.out.println(GSON.toJson(event)); event.getRecords().forEach(this::logDynamoDBRecord); return null; } private void logDynamoDBRecord(DynamodbStreamRecord record) { System.out.println(record.getEventID()); System.out.println(record.getEventName()); System.out.println("DynamoDB Record: " + GSON.toJson(record.getDynamodb())); } }
The following code example shows how to implement partial batch response for Lambda functions that receive events from a DynamoDB stream. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.
- SDK for Java 2.x
-
Note
There's more on GitHub. Find the complete example and learn how to set up and run in the Serverless examples
repository. Reporting DynamoDB batch item failures with Lambda using Java.
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 import com.amazonaws.services.lambda.runtime.Context; import com.amazonaws.services.lambda.runtime.RequestHandler; import com.amazonaws.services.lambda.runtime.events.DynamodbEvent; import com.amazonaws.services.lambda.runtime.events.StreamsEventResponse; import com.amazonaws.services.lambda.runtime.events.models.dynamodb.StreamRecord; import java.io.Serializable; import java.util.ArrayList; import java.util.List; public class ProcessDynamodbRecords implements RequestHandler<DynamodbEvent, Serializable> { @Override public StreamsEventResponse handleRequest(DynamodbEvent input, Context context) { List<StreamsEventResponse.BatchItemFailure> batchItemFailures = new ArrayList<>(); String curRecordSequenceNumber = ""; for (DynamodbEvent.DynamodbStreamRecord dynamodbStreamRecord : input.getRecords()) { try { //Process your record StreamRecord dynamodbRecord = dynamodbStreamRecord.getDynamodb(); curRecordSequenceNumber = dynamodbRecord.getSequenceNumber(); } catch (Exception e) { /* Since we are working with streams, we can return the failed item immediately. Lambda will immediately begin to retry processing from this failed item onwards. */ batchItemFailures.add(new StreamsEventResponse.BatchItemFailure(curRecordSequenceNumber)); return new StreamsEventResponse(batchItemFailures); } } return new StreamsEventResponse(); } }