Question

尊重，

我尝试使用新的Java NIO2在客户端和服务器端创建异步SocketChannel并进行通信，但问题是我发送到服务器上的套接字的所有消息，套接字都作为一条消息读取。这是代码：

我创建了用于编写和读取数据的处理程序：

ReadHandler：

public class ReadHandler implements CompletionHandler<Integer, Msg> {


private AsynchronousSocketChannel _socket;
private SocketHandler _socketHandler;

private ByteBuffer _buffer;

public ReadHandler(SocketHandler socketHandler) {

    this._socketHandler = socketHandler;
    _buffer = ByteBuffer.allocate(100);

    this._socket = this._socketHandler.getSocket();
    this._socket.read(_buffer, null, this);
}

@Override
public void completed(Integer result, Msg attachment) {

    System.out.println("readdddd " + result);

    String message = new String(_buffer.array());
    System.out.println("mess:" + message);

}

@Override
public void failed(Throwable exc, Msg attachment) {
    System.out.println(exc.getMessage());
}

}

ClientWriteHandler

public class ClientWriteHandler implements CompletionHandler<Integer, Msg> {

private AsynchronousSocketChannel _socket;
private ClientSocket _clientHandler;

private ByteBuffer _buffer;

public ClientWriteHandler(ClientSocket clientHandler) {


    this._clientHandler = clientHandler;
    _buffer = ByteBuffer.allocate(2048);
    this._socket = this._clientHandler.getSocket();
}

@Override
public void completed(Integer result, Msg attachment) {

    System.out.println("write " + result);
    _buffer.clear();
}

@Override
public void failed(Throwable exc, Msg attachment) {
    System.out.println(exc.getMessage());
}

public void write(String data) {
    _buffer = ByteBuffer.allocate(2048);
    this._socket.write(_buffer.wrap(data.getBytes()), new Msg(), this);

}

}

然后我调用写方法2次

socket = AsynchronousSocketChannel.open();
        socket.connect(new InetSocketAddress("localhost", port)).get();
        writeHandler = new ClientWriteHandler(this);
        writeHandler.write("hellooo server :)");
        writeHandler.write("hellooo server again :)");

我尝试在ByteBuffer上使用clear（）函数但没有效果。有什么建议吗？

Answer 1

抛出WritePendingException不是因为缓冲区已满。抛出它是因为写入没有完成但是另一个开始写入。

Answer 2

在第一次.write（）调用中发送几个字节，并在第二次调用中向.write（）发送几个字节。并且服务器全部接收它们。 TCP是面向字节的。如果您需要任何类似邮件的内容，则必须单独发送自己发送的邮件，例如：通过特殊的换行符或XML标签。

Answer 3

我正在努力，我找到了解决方案及其工作，正如我想象的那样。

在ClientWrite处理程序内部我添加了数据列表并在try..catch中设置了write方法以检查write（）是否已完成，如果写入仍在进行中，我将新字符串添加到数据列表中。写入方法完成后，我检查数据列表中的新消息并再次写入消息。

public class ClientWriteHandler implements CompletionHandler<Integer, ByteBuffer> {

private AsynchronousSocketChannel _socket;
private ClientSocket _clientHandler;

private ByteBuffer _buffer;
private List<String> datas;

private boolean finished;

public ClientWriteHandler(ClientSocket clientHandler) {


    this._clientHandler = clientHandler;
    _buffer = ByteBuffer.allocate(2048);
    this._socket = this._clientHandler.getSocket();
    finished = true;
    datas = new ArrayList<>();
}

@Override
public void completed(Integer result, ByteBuffer attachment) {

    System.out.println("client write complete " + result);

    if(datas.size() > 0) {
        this._socket.write(_buffer.wrap(datas.remove(0).getBytes()), _buffer, this);
    }
    else {
        /////
    }
}

@Override
public void failed(Throwable exc, ByteBuffer attachment) {
    System.out.println(exc.getMessage());
}

public void write(String data) {

    try {
        //finished = false;
        this._socket.write(_buffer.wrap(data.getBytes()), _buffer, this);
    }catch(WritePendingException ex) {

        datas.add(data);
    }
}

}

我也在附件中发送缓冲区。阅读完成后，在ReadHandler里面我清除了ByteBuffer并再次调用了read（）方法，所以接下来我读了新行，现在我不需要设置行分隔符。

public class ReadHandler implements CompletionHandler<Integer, ByteBuffer> {


private AsynchronousSocketChannel _socket;
private SocketHandler _socketHandler;

private ByteBuffer _buffer;

public ReadHandler(SocketHandler socketHandler) {

    this._socketHandler = socketHandler;
    _buffer = ByteBuffer.allocate(2048);

    this._socket = this._socketHandler.getSocket();
    this._socket.read(_buffer, _buffer, this);
}

@Override
public void completed(Integer result, ByteBuffer attachment) {

    attachment.flip();
    System.out.println("readdddd " + result);

    String message = new String(attachment.array());
    System.out.println("mess:" + message);

    _buffer.clear();
    this._socket.read(_buffer, _buffer, this);

}

@Override
public void failed(Throwable exc, ByteBuffer attachment) {
    System.out.println(exc.getMessage());
}

}

现在这个工作非常好，但是当我继续使用更复杂的东西时，我会检查这段代码的行为方式。你觉得这个解决方案怎么样呢？

AsynchronousSocketChannel在一个中写入/读取所有消息

3 个答案: