AWS Dynamo DB operations

package com.amazonaws.codesamples.datamodeling;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
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.DynamoDBMapperConfig;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable;

public class ObjectPersistenceCRUDExample {
    
    static AmazonDynamoDBClient client = new AmazonDynamoDBClient(new ProfileCredentialsProvider());
        
    public static void main(String[] args) throws IOException {
        testCRUDOperations();  
        System.out.println("Example complete!");
    }

    @DynamoDBTable(tableName="ProductCatalog")
    public static class CatalogItem {
        private Integer id;
        private String title;
        private String ISBN;
        private Set bookAuthors;
        
        @DynamoDBHashKey(attributeName="Id")
        public Integer getId() { return id; }
        public void setId(Integer id) { this.id = id; }
        
        @DynamoDBAttribute(attributeName="Title")
        public String getTitle() { return title; }    
        public void setTitle(String title) { this.title = title; }
        
        @DynamoDBAttribute(attributeName="ISBN")
        public String getISBN() { return ISBN; }    
        public void setISBN(String ISBN) { this.ISBN = ISBN;}
        
        @DynamoDBAttribute(attributeName = "Authors")
        public Set getBookAuthors() { return bookAuthors; }    
        public void setBookAuthors(Set bookAuthors) { this.bookAuthors = bookAuthors; }
        @Override
        public String toString() {
            return "Book [ISBN=" + ISBN + ", bookAuthors=" + bookAuthors
            + ", id=" + id + ", title=" + title + "]";            
        }
    }
        
    private static void testCRUDOperations() {

        CatalogItem item = new CatalogItem();
        item.setId(601);
        item.setTitle("Book 601");
        item.setISBN("611-1111111111");
        item.setBookAuthors(new HashSet(Arrays.asList("Author1", "Author2")));
        
        // Save the item (book).
        DynamoDBMapper mapper = new DynamoDBMapper(client);
        mapper.save(item);
        
        // Retrieve the item.
        CatalogItem itemRetrieved = mapper.load(CatalogItem.class, 601);
        System.out.println("Item retrieved:");
        System.out.println(itemRetrieved);

        // Update the item.
        itemRetrieved.setISBN("622-2222222222");
        itemRetrieved.setBookAuthors(new HashSet(Arrays.asList("Author1", "Author3")));
        mapper.save(itemRetrieved);
        System.out.println("Item updated:");
        System.out.println(itemRetrieved);
        
        // Retrieve the updated item.
        DynamoDBMapperConfig config = new DynamoDBMapperConfig(DynamoDBMapperConfig.ConsistentReads.CONSISTENT);
        CatalogItem updatedItem = mapper.load(CatalogItem.class, 601, config);
        System.out.println("Retrieved the previously updated item:");
        System.out.println(updatedItem);
        
        // Delete the item.
        mapper.delete(updatedItem);
        
        // Try to retrieve deleted item.
        CatalogItem deletedItem = mapper.load(CatalogItem.class, updatedItem.getId(), config);
        if (deletedItem == null) {
            System.out.println("Done - Sample item is deleted.");
        }
    }
}