UseDynamoMapping.java - AWS Code Sample

UseDynamoMapping.java

UseDynamoMapping.java demonstrates how to use the DynamoDB mapping functionality

/* Copyright 2010-2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. This file is licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance with the License. A copy of the License is located at http://aws.amazon.com/apache2.0/ This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package aws.example.dynamodb; import com.amazonaws.services.dynamodbv2.AmazonDynamoDB; import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder; import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAttribute; import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBHashKey; import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper; import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable; import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBRangeKey; import com.amazonaws.services.dynamodbv2.model.AmazonDynamoDBException; public class UseDynamoMapping { public static void main(String[] args) { final String USAGE = "\n" + "To run this example, supply the following values: \n" + "artist name \n" + "song title \n" + "album title \n" + "number of awards \n"; if (args.length < 4) { System.out.println(USAGE); System.exit(1); } String artist = args[0]; String songTitle = args[1]; String albumTitle = args[2]; String awards = args[3]; AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard().build(); MusicItems items = new MusicItems(); try{ // Add new content to the Music table items.setArtist(artist); items.setSongTitle(songTitle); items.setAlbumTitle(albumTitle); items.setAwards(Integer.parseInt(awards)); //convert to an int // Save the item DynamoDBMapper mapper = new DynamoDBMapper(client); mapper.save(items); // Load an item based on the Partition Key and Sort Key // Both values need to be passed to the mapper.load method String artistName = artist; String songQueryTitle = songTitle; // Retrieve the item MusicItems itemRetrieved = mapper.load(MusicItems.class, artistName, songQueryTitle); System.out.println("Item retrieved:"); System.out.println(itemRetrieved); // Modify the Award value itemRetrieved.setAwards(2); mapper.save(itemRetrieved); System.out.println("Item updated:"); System.out.println(itemRetrieved); System.out.print("Done"); } catch (AmazonDynamoDBException e) { e.getStackTrace(); } } @DynamoDBTable(tableName="Music") public static class MusicItems { //Set up Data Members that correspond to columns in the Music table private String artist; private String songTitle; private String albumTitle; private int awards; @DynamoDBHashKey(attributeName="Artist") public String getArtist() { return this.artist; } public void setArtist(String artist) { this.artist = artist; } @DynamoDBRangeKey(attributeName="SongTitle") public String getSongTitle() { return this.songTitle; } public void setSongTitle(String title) { this.songTitle = title; } @DynamoDBAttribute(attributeName="AlbumTitle") public String getAlbumTitle() { return this.albumTitle; } public void setAlbumTitle(String title) { this.albumTitle = title; } @DynamoDBAttribute(attributeName="Awards") public int getAwards() { return this.awards; } public void setAwards(int awards) { this.awards = awards; } } }

Sample Details

Service: dynamodb

Last tested: 2019-12-16

Author: scmacdon-AWS

Type: full-example