如何编码 BatchWriteItemRequest 并保存数据

private static void saveItem(List<EventTracker> items) {
    List<WriteRequest> wrList = new ArrayList<>();
    try {

        for (EventTracker item : items) {
            WriteRequest wreqItem;
            wreqItem = getWriteRequest(item);
            wrList.add(wreqItem);
        }

        try {

            BatchWriteItemResult batchWriteItemResult = new BatchWriteItemResult();
            do {
                BatchWriteItemRequest batchWriteItemRequest = new BatchWriteItemRequest();
                batchWriteItemRequest.addRequestItemsEntry(forumTableName, wrList);// setRequestItems(writeRequestitems);
                batchWriteItemResult = amazonDynamoDB.batchWriteItem(batchWriteItemRequest);
                // Check for unprocessed keys which could happen if you
                // exceed
                // provisioned throughput
                Map<String, List<WriteRequest>> unprocessedItems = batchWriteItemResult.getUnprocessedItems();
                if (unprocessedItems.size() == 0) {
                    System.out.println("No unprocessed items found");
                } else {
                    System.out.println("Sleeping for: " + ThreadLocalRandom.current().nextInt(500, 999 + 1));
                    Thread.sleep(ThreadLocalRandom.current().nextInt(500, 999 + 1));
                    wrList = unprocessedItems.get(forumTableName);
                    System.out.println("Retrieving the unprocessed items");
                }

            } while (batchWriteItemResult.getUnprocessedItems().size() > 0);

        } catch (Exception e) {
            System.err.println("Failed to retrieve items: ");
            e.printStackTrace(System.err);
        }

    } catch (Exception e) {

    }
}

如果我们想要使用批处理操作将数据放入 dynamo db 表，我们需要知道这一点。让我们看看完成此任务需要遵循的步骤。在这个例子中，我们试图保留一个 EventTracker 数据列表，这是我的 POJO。

1. 对于要插入的每条记录，我们需要创建一个 PUT 请求。
2. 每个 PUT 请求都包含在写请求中。
3. 所有写请求都绑定在一个列表中。
4. 然后将 WriteRequest 列表添加到 BatchWriteItemRequest 并执行。

下面的代码将显示我们如何创建写请求。