Binding-Server-Socket Ausnahme im Thread "Haupt" java.net.BindException: Adresse bereits verwendet: JVM_Bind Java

Question

Ich versuche, ein Java-Programm zu erstellen, um eine Nachricht vom Client an den Server zu senden und eine Antwort zurück mit Socket-Programmierung empfangen es kommt mit diesem Fehler auf:

Exception in thread "main" java.net.BindException: Address already in use: JVM_Bind at java.net.DualStackPlainSocketImpl.bind0(Native Method) at java.net.DualStackPlainSocketImpl.socketBind(DualStackPlainSocketImpl.java:106) at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:387) at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:190) at java.net.ServerSocket.bind(ServerSocket.java:375) at java.net.ServerSocket.(ServerSocket.java:237) at java.net.ServerSocket.(ServerSocket.java:128) at Bob.main(Bob.java:9)

Client-Seite:

public static void main(String[] args) throws IOException { 

    InetAddress addr = InetAddress.getByName("127.0.0.1") ; //set the address of the server to be connected to. Any IP address can be set here as a string 
    //If the name is saved in your "etc/hosts" file, then the name can be used instead of the ip address 
    //Alternative method: InetAddress.getByAddress -see "stackoverflow" explanation if interested 

    System.out.println("addr = " + addr); 

    Socket socket = new Socket(addr, 8080); //attempt to connect to the server by creating a socket using the IP address and Port number of the server 

    try { 
     System.out.println("socket = " + socket); 
     BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())); //create an input variable for the socket- accepts input from the socket 

     PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true); // create an output variable for the socket- writes output to the socket 

     //this loop simply writes to the socket 10 times waits for a reply from the socket and then prints the reply received 
     for(int i = 0; i < 10; i ++) { 
      out.println("I am it: " + i); //write to socket 
      String str = in.readLine(); //read from socket 
      System.out.println(str); //print to console line read from socket 
     } 

     out.println("END"); //send string that indicates end of transmission 

    }catch(SocketException e) { 
     System.out.println("Server closed connection"); 
    }finally{ 
     System.out.println("closing..."); 
     socket.close(); //close the connection 
    } 
} 

Server-Seite:

public static final int PORT = 8080; 
    public static void main(String[] args) throws IOException { 

    ServerSocket s = new ServerSocket(PORT); //create server socket object 
    System.out.println("Started: " + s); 

    try { 
     Socket socket = s.accept(); //accept a socket connection using the Server Socket created previously 
     try { 
      System.out.println("Connection accepted: "+ socket); 

      BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())); //create an input variable for the socket- accepts input from the socket 

      PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true); // create an output variable for the socket- writes output to the socket 


      //this loop accepts input from the socket, prints out what it receives anc echoes it back into the socket until it recives the word "END" indicating the end of transmission 
      while (true) { 
       String str = in.readLine(); //read line from socket 
       if (str.equals("END")) break; 
       System.out.println("Echoing: " + str); //print line to console 
       out.println("You said: " + str); //echo line read back into socket 
      } 


     }catch (SocketException e) { 
      System.out.println("Client closed connection"); 
     }finally{    //close the present connection 
      System.out.println("closing..."); 
      socket.close(); 
     } 

    }catch(SocketException e){ 
     System.out.println("Server socket closed unexpectedly"); 
    }finally{    //close the server socket. i.e. stop listening for connections 
     s.close();   //without this line, the server would continue waiting for another connection 
    } 
} 

Answer 1

java.net.BindException bedeutet, dass Sie versuchen, an einen bereits belegten Port zu binden.

Sie entweder zwei Instanzen von Ihnen Server läuft, oder ein anderes Programm bereits Port 8080