DynamoDBMapper batch operations

The following Java code example declares Book, Forum, Thread, and Reply classes and maps them to the Amazon DynamoDB tables using the DynamoDBMapper class.

The code illustrates the following batch write operations:

For more information about the tables used in this example, see Creating tables and loading data for code examples in DynamoDB. For step-by-step instructions for testing the following example, see Java code examples.

Imports

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

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.DynamoDBMapperConfig;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBRangeKey;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable;

Code

public class DynamoDBMapperBatchWriteExample {

    static AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard().build();

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

            DynamoDBMapper mapper = new DynamoDBMapper(client);

            testBatchSave(mapper);
            testBatchDelete(mapper);
            testBatchWrite(mapper);

            System.out.println("Example complete!");

        } catch (Throwable t) {
            System.err.println("Error running the DynamoDBMapperBatchWriteExample: " + t);
            t.printStackTrace();
        }
    }

    private static void testBatchSave(DynamoDBMapper mapper) {

        Book book1 = new Book();
        book1.setId(901);
        book1.setInPublication(true);
        book1.setISBN("902-11-11-1111");
        book1.setPageCount(100);
        book1.setPrice(10);
        book1.setProductCategory("Book");
        book1.setTitle("My book created in batch write");

        Book book2 = new Book();
        book2.setId(902);
        book2.setInPublication(true);
        book2.setISBN("902-11-12-1111");
        book2.setPageCount(200);
        book2.setPrice(20);
        book2.setProductCategory("Book");
        book2.setTitle("My second book created in batch write");

        Book book3 = new Book();
        book3.setId(903);
        book3.setInPublication(false);
        book3.setISBN("902-11-13-1111");
        book3.setPageCount(300);
        book3.setPrice(25);
        book3.setProductCategory("Book");
        book3.setTitle("My third book created in batch write");

        System.out.println("Adding three books to ProductCatalog table.");
        mapper.batchSave(Arrays.asList(book1, book2, book3));
    }

    private static void testBatchDelete(DynamoDBMapper mapper) {

        Book book1 = mapper.load(Book.class, 901);
        Book book2 = mapper.load(Book.class, 902);
        System.out.println("Deleting two books from the ProductCatalog table.");
        mapper.batchDelete(Arrays.asList(book1, book2));
    }

    private static void testBatchWrite(DynamoDBMapper mapper) {

        // Create Forum item to save
        Forum forumItem = new Forum();
        forumItem.setName("Test BatchWrite Forum");
        forumItem.setThreads(0);
        forumItem.setCategory("Amazon Web Services");

        // Create Thread item to save
        Thread threadItem = new Thread();
        threadItem.setForumName("AmazonDynamoDB");
        threadItem.setSubject("My sample question");
        threadItem.setMessage("BatchWrite message");
        List<String> tags = new ArrayList<String>();
        tags.add("batch operations");
        tags.add("write");
        threadItem.setTags(new HashSet<String>(tags));

        // Load ProductCatalog item to delete
        Book book3 = mapper.load(Book.class, 903);

        List<Object> objectsToWrite = Arrays.asList(forumItem, threadItem);
        List<Book> objectsToDelete = Arrays.asList(book3);

        DynamoDBMapperConfig config = DynamoDBMapperConfig.builder()
                .withSaveBehavior(DynamoDBMapperConfig.SaveBehavior.CLOBBER)
                .build();

        mapper.batchWrite(objectsToWrite, objectsToDelete, config);
    }

    @DynamoDBTable(tableName = "ProductCatalog")
    public static class Book {
        private int id;
        private String title;
        private String ISBN;
        private int price;
        private int pageCount;
        private String productCategory;
        private boolean inPublication;

        // Partition key
        @DynamoDBHashKey(attributeName = "Id")
        public int getId() {
            return id;
        }

        public void setId(int 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 = "Price")
        public int getPrice() {
            return price;
        }

        public void setPrice(int price) {
            this.price = price;
        }

        @DynamoDBAttribute(attributeName = "PageCount")
        public int getPageCount() {
            return pageCount;
        }

        public void setPageCount(int pageCount) {
            this.pageCount = pageCount;
        }

        @DynamoDBAttribute(attributeName = "ProductCategory")
        public String getProductCategory() {
            return productCategory;
        }

        public void setProductCategory(String productCategory) {
            this.productCategory = productCategory;
        }

        @DynamoDBAttribute(attributeName = "InPublication")
        public boolean getInPublication() {
            return inPublication;
        }

        public void setInPublication(boolean inPublication) {
            this.inPublication = inPublication;
        }

        @Override
        public String toString() {
            return "Book [ISBN=" + ISBN + ", price=" + price + ", product category=" + productCategory + ", id=" + id
                    + ", title=" + title + "]";
        }

    }

    @DynamoDBTable(tableName = "Reply")
    public static class Reply {
        private String id;
        private String replyDateTime;
        private String message;
        private String postedBy;

        // Partition key
        @DynamoDBHashKey(attributeName = "Id")
        public String getId() {
            return id;
        }

        public void setId(String id) {
            this.id = id;
        }

        // Sort key
        @DynamoDBRangeKey(attributeName = "ReplyDateTime")
        public String getReplyDateTime() {
            return replyDateTime;
        }

        public void setReplyDateTime(String replyDateTime) {
            this.replyDateTime = replyDateTime;
        }

        @DynamoDBAttribute(attributeName = "Message")
        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        @DynamoDBAttribute(attributeName = "PostedBy")
        public String getPostedBy() {
            return postedBy;
        }

        public void setPostedBy(String postedBy) {
            this.postedBy = postedBy;
        }
    }

    @DynamoDBTable(tableName = "Thread")
    public static class Thread {
        private String forumName;
        private String subject;
        private String message;
        private String lastPostedDateTime;
        private String lastPostedBy;
        private Set<String> tags;
        private int answered;
        private int views;
        private int replies;

        // Partition key
        @DynamoDBHashKey(attributeName = "ForumName")
        public String getForumName() {
            return forumName;
        }

        public void setForumName(String forumName) {
            this.forumName = forumName;
        }

        // Sort key
        @DynamoDBRangeKey(attributeName = "Subject")
        public String getSubject() {
            return subject;
        }

        public void setSubject(String subject) {
            this.subject = subject;
        }

        @DynamoDBAttribute(attributeName = "Message")
        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        @DynamoDBAttribute(attributeName = "LastPostedDateTime")
        public String getLastPostedDateTime() {
            return lastPostedDateTime;
        }

        public void setLastPostedDateTime(String lastPostedDateTime) {
            this.lastPostedDateTime = lastPostedDateTime;
        }

        @DynamoDBAttribute(attributeName = "LastPostedBy")
        public String getLastPostedBy() {
            return lastPostedBy;
        }

        public void setLastPostedBy(String lastPostedBy) {
            this.lastPostedBy = lastPostedBy;
        }

        @DynamoDBAttribute(attributeName = "Tags")
        public Set<String> getTags() {
            return tags;
        }

        public void setTags(Set<String> tags) {
            this.tags = tags;
        }

        @DynamoDBAttribute(attributeName = "Answered")
        public int getAnswered() {
            return answered;
        }

        public void setAnswered(int answered) {
            this.answered = answered;
        }

        @DynamoDBAttribute(attributeName = "Views")
        public int getViews() {
            return views;
        }

        public void setViews(int views) {
            this.views = views;
        }

        @DynamoDBAttribute(attributeName = "Replies")
        public int getReplies() {
            return replies;
        }

        public void setReplies(int replies) {
            this.replies = replies;
        }

    }

    @DynamoDBTable(tableName = "Forum")
    public static class Forum {
        private String name;
        private String category;
        private int threads;

        // Partition key
        @DynamoDBHashKey(attributeName = "Name")
        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        @DynamoDBAttribute(attributeName = "Category")
        public String getCategory() {
            return category;
        }

        public void setCategory(String category) {
            this.category = category;
        }

        @DynamoDBAttribute(attributeName = "Threads")
        public int getThreads() {
            return threads;
        }

        public void setThreads(int threads) {
            this.threads = threads;
        }
    }
}