使用Java中的Thrift進行異步請求

Question

我正在尋找一個如何使用Thrift在Java中創建異步請求的示例。 看看生成的代碼這似乎是可能的，但我找不到一個如何的例子。

以下是生成代碼的示例，該代碼表明存在異步接口：

...
AsyncIface {
    public static class Factory implements org.apache.thrift.async.TAsyncClientFactory<AsyncClient> {
      private org.apache.thrift.async.TAsyncClientManager clientManager;
      private org.apache.thrift.protocol.TProtocolFactory protocolFactory;
      public Factory(org.apache.thrift.async.TAsyncClientManager clientManager, org.apache.thrift.protocol.TProtocolFactory protocolFactory) {
        this.clientManager = clientManager;
        this.protocolFactory = protocolFactory;
      }
      public AsyncClient getAsyncClient(org.apache.thrift.transport.TNonblockingTransport transport) {
        return new AsyncClient(protocolFactory, clientManager, transport);
      }
    }
 ...

關於如何使用它的任何指針？

Answer 1

使用上面的界面進行這樣的異步調用（代碼提到了Cassandra，但很容易推廣到你的應用程序）：

TNonblockingTransport transport = new TNonblockingSocket("127.0.0.1", 9160);
TAsyncClientManager clientManager = new TAsyncClientManager();
TProtocolFactory protocolFactory = new TBinaryProtocol.Factory();
Cassandra.AsyncClient client = new Cassandra.AsyncClient(protocolFactory, clientManager, transport);

Cassandra.method_call(parameters, new Callback());

Answer 2

您沒有給出任何背景信息，因此我將為您提供您需要的基本部分：

• 要執行異步調用，您需要在線程中進行調用
• 要獲得結果，您需要進行某種回調

以下代表了這些元素的基本示例：

final MyClient client;  // Who will get a call back to the their sendResult() method when asynch call finished
ExecutorService executor = Executors.newSingleThreadExecutor(); // Handy way to run code in a thread
Runnable task = new Runnable() { 
    public void run() { // Where the "do the call" code sits
        int result = someService.call(someParamter);
        client.sendResult(result); // For example, expecting an int result
    }
};
executor.submit(task); // This scheduled the runnable to be run