Question

我在linux中使用服务器套接字，我需要关闭它并在time_wait TCP状态到期之前重新打开。我在绑定之前设置了服务器套接字的重用地址选项，但它仍然抛出BindException。我也试过这个http://meteatamel.wordpress.com/2010/12/01/socket-reuseaddress-property-and-linux/，但它仍然不起作用。

要打开服务器套接字我使用：

ServerSocket ss = new ServerSocket();
ss.setReuseAddress(true);
ss.bind(new InetSocketAddress(12345));

并关闭：

ss.close();

“已在使用的地址”BindException在绑定调用时被抛出。

此代码生成异常：

for (int i = 0; i < 2; i++) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    final ServerSocket ss = new ServerSocket();
                    ss.setReuseAddress(true);
                    ss.bind(new InetSocketAddress(12345));
                    Socket s = ss.accept();
                    System.out.println((char) s.getInputStream().read());
                    ss.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
        Thread.sleep(500);
        Socket s = new Socket("localhost", 12345);
        s.getOutputStream().write('c');
    }

Answer 1

在绑定之前设置重用而不是在获得异常之后。

ServerSocket ss = new ServerSocket(); // don't bind just yet ss.setReuseAddress(true); ss.bind(new InetSocketAddress(12345)); // can bind with reuse= true

在Windows 7和RHEL 5.x上运行时没有错误

for (int i = 0; i < 1000; i++) { Thread t = new Thread(new Runnable() { @Override public void run() { try { final ServerSocket ss = new ServerSocket(); ss.setReuseAddress(true); ss.bind(new InetSocketAddress(12345)); Socket s = ss.accept(); System.out.println((char) s.getInputStream().read()); ss.close(); } catch (IOException e) { e.printStackTrace(); } } }); t.start(); Thread.sleep(50); Socket s = new Socket("localhost", 12345); s.getOutputStream().write('c'); t.join(); }

Answer 2

你必须这样做：它意味着提取代码，使其不再发生

public class....

private ServerSocket socServer;

onCreate
...

try {
    socServer = new ServerSocket();
    socServer.setReuseAddress(true);
    socServer.bind(new InetSocketAddress(SERVER_PORT));
} catch (IOException e) {
 e.printStackTrace();
}

// New thread to listen to incoming connections
new Thread(new Runnable() {
    @Override
    public void run() {
        try 
        {
            // Create server side client socket reference
            Socket socClient = null;

            // Infinite loop will listen for client requests to connect
            while (true) {
                // Accept the client connection and hand over communication 
                // to server side client socket
                   socClient = socServer.accept();

               // For each client new instance of AsyncTask will be created
                  ServerAsyncTask serverAsyncTask = new ServerAsyncTask();

               // Start the AsyncTask execution 
               // Accepted client socket object will pass as the parameter
               serverAsyncTask.execute(new Socket[] {socClient});
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}).start();

Java服务器套接字不重用地址

2 个答案: