Esempio: crea, aggiorna, elimina ed elenca le tabelle utilizzando l'API del documento AWS SDK for Java

Nel seguente codice di esempio viene usata l'API documento AWS SDK for Java per creare, aggiornare ed eliminare una tabella Amazon DynamoDB (ExampleTable). Come parte dell'aggiornamento della tabella, vengono aumentati i valori del throughput assegnato. L'esempio consente di elencare anche tutte le tabelle nel tuo account e ottenere la descrizione di una tabella specifica. Per step-by-step istruzioni su come eseguire l'esempio seguente, vedereEsempi di codice Java.

package com.amazonaws.codesamples.document;

import java.util.ArrayList;
import java.util.Iterator;

import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;
import com.amazonaws.services.dynamodbv2.document.DynamoDB;
import com.amazonaws.services.dynamodbv2.document.Table;
import com.amazonaws.services.dynamodbv2.document.TableCollection;
import com.amazonaws.services.dynamodbv2.model.AttributeDefinition;
import com.amazonaws.services.dynamodbv2.model.CreateTableRequest;
import com.amazonaws.services.dynamodbv2.model.KeySchemaElement;
import com.amazonaws.services.dynamodbv2.model.KeyType;
import com.amazonaws.services.dynamodbv2.model.ListTablesResult;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
import com.amazonaws.services.dynamodbv2.model.TableDescription;

public class DocumentAPITableExample {

    static AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard().build();
    static DynamoDB dynamoDB = new DynamoDB(client);

    static String tableName = "ExampleTable";

    public static void main(String[] args) throws Exception {

        createExampleTable();
        listMyTables();
        getTableInformation();
        updateExampleTable();

        deleteExampleTable();
    }

    static void createExampleTable() {

        try {

            List<AttributeDefinition> attributeDefinitions = new ArrayList<AttributeDefinition>();
            attributeDefinitions.add(new AttributeDefinition().withAttributeName("Id").withAttributeType("N"));

            List<KeySchemaElement> keySchema = new ArrayList<KeySchemaElement>();
            keySchema.add(new KeySchemaElement().withAttributeName("Id").withKeyType(KeyType.HASH)); // Partition
                                                                                                     // key

            CreateTableRequest request = new CreateTableRequest().withTableName(tableName).withKeySchema(keySchema)
                    .withAttributeDefinitions(attributeDefinitions).withProvisionedThroughput(
                            new ProvisionedThroughput().withReadCapacityUnits(5L).withWriteCapacityUnits(6L));

            System.out.println("Issuing CreateTable request for " + tableName);
            Table table = dynamoDB.createTable(request);

            System.out.println("Waiting for " + tableName + " to be created...this may take a while...");
            table.waitForActive();

            getTableInformation();

        } catch (Exception e) {
            System.err.println("CreateTable request failed for " + tableName);
            System.err.println(e.getMessage());
        }

    }

    static void listMyTables() {

        TableCollection<ListTablesResult> tables = dynamoDB.listTables();
        Iterator<Table> iterator = tables.iterator();

        System.out.println("Listing table names");

        while (iterator.hasNext()) {
            Table table = iterator.next();
            System.out.println(table.getTableName());
        }
    }

    static void getTableInformation() {

        System.out.println("Describing " + tableName);

        TableDescription tableDescription = dynamoDB.getTable(tableName).describe();
        System.out.format(
                "Name: %s:\n" + "Status: %s \n" + "Provisioned Throughput (read capacity units/sec): %d \n"
                        + "Provisioned Throughput (write capacity units/sec): %d \n",
                tableDescription.getTableName(), tableDescription.getTableStatus(),
                tableDescription.getProvisionedThroughput().getReadCapacityUnits(),
                tableDescription.getProvisionedThroughput().getWriteCapacityUnits());
    }

    static void updateExampleTable() {

        Table table = dynamoDB.getTable(tableName);
        System.out.println("Modifying provisioned throughput for " + tableName);

        try {
            table.updateTable(new ProvisionedThroughput().withReadCapacityUnits(6L).withWriteCapacityUnits(7L));

            table.waitForActive();
        } catch (Exception e) {
            System.err.println("UpdateTable request failed for " + tableName);
            System.err.println(e.getMessage());
        }
    }

    static void deleteExampleTable() {

        Table table = dynamoDB.getTable(tableName);
        try {
            System.out.println("Issuing DeleteTable request for " + tableName);
            table.delete();

            System.out.println("Waiting for " + tableName + " to be deleted...this may take a while...");

            table.waitForDelete();
        } catch (Exception e) {
            System.err.println("DeleteTable request failed for " + tableName);
            System.err.println(e.getMessage());
        }
    }

}