Amazon DynamoDB
开发人员指南 (API Version 2012-08-10)
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示例:批量写入操作

以下 Java 代码示例声明了 Book、Forum、Thread 和 Reply 类,并使用 DynamoDBMapper 类将这些类映射到 DynamoDB 表。

该代码说明了以下批量写入操作:

  • batchSave 在 ProductCatalog 表中放置图书项目。

  • batchDelete 删除 ProductCatalog 表中的项目。

  • batchWrite 向 Forum 表和 Thread 表放置项目以及从中删除项目。

有关此示例中使用的表的更多信息,请参阅创建表并加载示例数据。有关测试以下示例的分步说明,请参阅Java 代码示例

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// Copyright 2012-2015 Amazon.com, Inc. or its affiliates. All Rights Reserved. // Licensed under the Apache License, Version 2.0. package com.amazonaws.codesamples.datamodeling; 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; public class DynamoDBMapperBatchWriteExample { static AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard().build(); static SimpleDateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); 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.id = 901; book1.inPublication = true; book1.ISBN = "902-11-11-1111"; book1.pageCount = 100; book1.price = 10; book1.productCategory = "Book"; book1.title = "My book created in batch write"; Book book2 = new Book(); book2.id = 902; book2.inPublication = true; book2.ISBN = "902-11-12-1111"; book2.pageCount = 200; book2.price = 20; book2.productCategory = "Book"; book2.title = "My second book created in batch write"; Book book3 = new Book(); book3.id = 903; book3.inPublication = false; book3.ISBN = "902-11-13-1111"; book3.pageCount = 300; book3.price = 25; book3.productCategory = "Book"; book3.title = "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.name = "Test BatchWrite Forum"; forumItem.threads = 0; forumItem.category = "Amazon Web Services"; // Create Thread item to save Thread threadItem = new Thread(); threadItem.forumName = "AmazonDynamoDB"; threadItem.subject = "My sample question"; threadItem.message = "BatchWrite message"; List<String> tags = new ArrayList<String>(); tags.add("batch operations"); tags.add("write"); threadItem.tags = 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 = new DynamoDBMapperConfig(DynamoDBMapperConfig.SaveBehavior.CLOBBER); 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; } } }