當停止我的TCP服務器時拋出SocketException java

Question

從我的表單關閉我的TCP服務器時出現此錯誤。

java.net.SocketException: Socket closed 
    at java.net.PlainSocketImpl.socketAccept(Native Method) 
    at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:404) 
    at java.net.ServerSocket.implAccept(ServerSocket.java:545) 
    at java.net.ServerSocket.accept(ServerSocket.java:513) 
    at com.hightekjonathan.HomeServer.Server.Start(Server.java:36) 
    at com.hightekjonathan.HomeServer.Form$2.run(Form.java:81) 
    at java.lang.Thread.run(Thread.java:745) 

繼承人的Server.java：

import java.io.DataInputStream; 
import java.io.DataOutputStream; 
import java.io.IOException; 
import java.net.*; 
import java.util.Enumeration; 

public class Server { 
    private static ServerSocket serverSocket = null; 
    private static Socket socket = null; 
    private static DataInputStream dataInputStream = null; 
    private static DataOutputStream dataOutputStream = null; 

    private static int port = 19586; 

    private static boolean running = false; 

    public void Start() { 
     try { 
      System.out.println("Starting Server..."); 

      serverSocket = new ServerSocket(port); 

      System.out.println("Server Started"); 
      System.out.println("IP Address: " + getIpAddress()); 
      System.out.println("Listening: " + serverSocket.getLocalPort()); 

      running = true; 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 

     try { 
      System.out.println("Attempting to connect to clients..."); 
      socket = serverSocket.accept(); 

      dataInputStream = new DataInputStream(socket.getInputStream()); 
      dataOutputStream = new DataOutputStream(socket.getOutputStream()); 

      System.out.println("ip: " + socket.getInetAddress()); 
      System.out.println("message: " + dataInputStream.readUTF()); 

      dataOutputStream.writeUTF("connected"); 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    public void Stop() { 
     if (running) { 
      if (socket != null) { 
       try { 
        socket.close(); 
        socket = null; 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 

      if (dataInputStream != null) { 
       try { 
        dataInputStream.close(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
      } 

      if (dataOutputStream != null) { 
       try { 
        dataOutputStream.close(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
      } 

      if (serverSocket != null) { 
       try { 
        serverSocket.close(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
      } 

      running = false; 
     } 
    } 

    private String getIpAddress() { 
     String ip = ""; 
     try { 
      Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface.getNetworkInterfaces(); 
      while (enumNetworkInterfaces.hasMoreElements()) { 
       NetworkInterface networkInterface = enumNetworkInterfaces.nextElement(); 
       Enumeration<InetAddress> enumInetAddress = networkInterface.getInetAddresses(); 
       while (enumInetAddress.hasMoreElements()) { 
        InetAddress inetAddress = enumInetAddress.nextElement(); 

        if (inetAddress.isSiteLocalAddress()) { 
         ip += inetAddress.getHostAddress(); 
        } 
       } 
      } 

     } catch (SocketException e) { 
      e.printStackTrace(); 
      ip += "Something Wrong! " + e.toString() + "\n"; 
     } 

     return ip; 
    } 

    public boolean isRunning() { 
     return running; 
    } 
} 

其使用此功能並開始一個新的線程從我的GUI形式：

button.addActionListener(new java.awt.event.ActionListener() { 
    public void actionPerformed(java.awt.event.ActionEvent evt) { 
     buttonActionPerformed(evt); 
    } 
); 

然後buttonActionPerformed()是這樣的：

private void buttonActionPerformed(java.awt.event.ActionEvent evt) { 
    if (!server.isRunning()) { 
     Runnable r = new Runnable() { 
      public void run() { 
       server.Start(); 
      } 
     }; 
     new Thread(r).start(); 

     button.setText("Stop Server"); 
     serverStatus.setText("Server: Started"); 
    } else { 
     server.Stop(); 

     button.setText("Start Server"); 
     serverStatus.setText("Server: Stopped"); 
    } 
} 

e當沒有客戶端連接時，我停止服務器時纔會出現rror。但是，當一個客戶端連接，然後斷開連接，我沒有得到那個錯誤。它正確地關閉它，我只是想確保錯誤不會是一個嚴重的問題，或者如果有一個簡單的方法來修復它。

Answer 1

當你啓動你的服務器時，你調用serverSocket.accept（）。這個調用會阻塞線程直到建立連接。通過調用server.stop（），您正在另一個線程中關閉此服務器套接字。 ServerSocket.close（）JavaDoc說： Any thread currently blocked in {@link #accept()} will throw a {@link SocketException}.

所以這就是爲什麼你得到這個異常。

我想你可以忽略這個例外。

P.S. 而且你應該讓你的boolean running不穩定。