首页 > 技术文章 > java.net.SocketException: recvfrom failed: EBADF (Bad file descriptor)

xuanwei-qingfeng 2018-11-12 18:40 原文

1. 问题说明:

与服务器之间进行socket通信的时候,客户端关闭socket之后,会抛出一个IOException,异常信息如下:

java.net.SocketException: recvfrom failed: EBADF (Bad file descriptor)

2. 问题分析:

根据异常分析,定位到这是关闭socket之后持续进行读操作导致

 

private InputStream is;

private OutputStream out;

private Socket socket;

private int type;


// socket连接

private class CommandReceiver extends Thread {
  
        @Override
        public void run() {
            try {
                byte[] data;
                if (socket != null && socket.isConnected() && !socket.isClosed()) {
                    is = socket.getInputStream();
                    while (true) {
                        //读取数据
                        byte[] responseData = readOneFrame(is);
                        //......解析数据
                        //......解析数据
                       switch(type) {
                       case 1:
                               //业务处理
                               break;
                       case 2:
                               is.close();
                               os.close();
                               socket.close();
                       default:
                               break;
                       }
              }
        }
     }
}

 

查看代码得知,这里关闭socket之后,while循环并没有结束,仍然还在进行读操作。

3.问题解决

因此需要在socket关闭之后,同时关闭掉while循环,此处将while循环这里增加一个判断的booean值即可。

private InputStream is;

private OutputStream out;

private Socket socket;

private int type;

private boolean hasRead = false;


// socket连接

private hasRead = true;

private class CommandReceiver extends Thread {
  
        @Override
        public void run() {
            try {
                byte[] data;
                if (socket != null && socket.isConnected() && !socket.isClosed()) {
                    is = socket.getInputStream();
                    while (hasRead) {
                        //读取数据
                        byte[] responseData = readOneFrame(is);
                        //......解析数据
                        //......解析数据
                       switch(type) {
                       case 1:
                               //业务处理
                               break;
                       case 2:
                               is.close();
                               os.close();
                               socket.close();
                               hasRead=false;
                       default:
                               break;
                       }
              }
        }
     }
}

  

 

 

 

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