Java,获得一个奇怪的Socket异常:“断管”和“操作超时”

时间:2011-11-11 04:16:04

标签: java sockets exception tcp

我有一个客户端服务器应用程序,它有16个线程(8个客户端,8个服务器),每个都有1-1个匹配的TCP连接(所以8个TCP流)。

我让服务器发送X量的随机字节然后关闭。同时客户端只读取X数据然后关闭。 X是预定的。我也使用虚拟网络进行带宽限制,但我正在离开带有足够带宽(100Mbps)的管道。有时它工作正常,有时我得到这些例外。我在大约3.5分钟内在所有8个连接上均匀地传输1GB传播。

客户端抛出此异常:

java.net.SocketException: Operation timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at miccbull.parralleltcp.client.StreamWorker.run(StreamWorker.java:43)

服务器抛出此异常:

java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStream.java:124)
at miccbull.parralleltcp.server.TransmissionWorker.run(TransmissionWorker.java:51)

服务器代码:

public void run() {

    OutputStream os = null;

    try {
        socket = sSocket.accept();
        os = socket.getOutputStream();
    } catch (IOException e2) {
        e2.printStackTrace();
    }

    //send the data
    for(int i = 0; i < Server.TRANSMISSIONS; i++){
        System.out.println(sSocket.getLocalPort() + " sending set " + (i+1) + " of " + Server.TRANSMISSIONS);

        try {
            os.write(new byte[Server.FILE_SIZE/Server.numStreams/Server.TRANSMISSIONS]);
            os.flush();
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Closing server (at write bytes) with socket id: " + sSocket.getLocalPort());
        } 
    }

    System.out.println("Worker " + sSocket.getLocalPort() + " done");

    //close the socket
    try {
        socket.close();
        sSocket.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

客户代码:

    public void run(){

    byte[] bytes = new byte[1024];  //number of bytes to read per client stream
    InputStream is = null;

    //connect to server
    try {
        connectionSocket = new Socket("localhost", id);
        is = connectionSocket.getInputStream();
    } catch (UnknownHostException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }


    //read file from server
    int value = 0;
    int bytesRead = 0;
    try {

        while(bytesRead < (Client.FILE_SIZE/Client.NUM_STREAMS)){
            value = is.read(bytes, 0, 1024);
            if(value == -1){
                System.out.println("******************************** Read is -1 for client " + id);
            }
            else if(value == 0){
                System.out.println("******************************** Read is 0 for client " + id);
            }
            bytesRead += value;
        }
    } catch (IOException e) {
        System.out.println("**** Exception in read in client " + id + " and value value was: " + value);
        if(bytesRead == (Client.FILE_SIZE/Client.NUM_STREAMS)){
            System.out.println("************ NOT ACTUALLY BAD" + id);
        }
        e.printStackTrace();
    }

    //Finished download
    Client.workerDone();
    System.out.println("Worker " + id + " done received " + bytesRead);

导致这些例外的原因是什么?

2 个答案:

答案 0 :(得分:0)

您的客户端永远不会停止阅读,因为您没有测试read()返回&lt; 0

答案 1 :(得分:-1)

以下是我在您的代码中看到的内容:

  1. 我已经确认,对socket.getOutputStream()socket.getInputStream()的每次调用都会返回与套接字关联的不同的流。你应该每个插槽调用一次,并将结果放在一个局部变量中。

    OutputStream outputStream = socket.getOutputStream();
    // send the data
    for (int i = 0; i < 10; i++) {
        ....
        outputStream.write(...);
    
  2. 您应该从run()方法返回许多地方,但我怀疑您知道这一点。

  3. 您没有检查read()的返回值,看它是否在EOF上返回-1。您不应该只假设您获得正确的字节数。

  4. 我假设您正在编写空字符块,原因很简单。