CODEWITHSUNDEEP
javasocketsclient-server
ahtsan
ahtsan

Reputation: 273

(Java Multiclient server) No exception when client closes socket and server writes to client

Server code:

public class Main {
    public static void main(String args[]){
        Socket s=null;
        ServerSocket ss2=null;
        System.out.println("Server Listening......");
        try{
            ss2 = new ServerSocket(8080);
        }
        catch(IOException e){
            e.printStackTrace();
            System.out.println("Server error");
        }

        while(true){
            try{
                s = ss2.accept();
                ss2.setReuseAddress(true);
                System.out.println("connection Established");
                ServerThread st=new ServerThread(s);
                st.start();
            }
            catch(Exception e){
                e.printStackTrace();
                System.out.println("Connection Error");
            }
        }
    }
}

class ServerThread extends Thread{  

    String line; = "testing";
    PrintWriter os=null;
    Socket s=null;

    public ServerThread(Socket s){
        this.s=s;
    }

    public void run() {
        try{
            os=new PrintWriter(s.getOutputStream());

        }catch(IOException e){
            System.out.println("IO error in server thread");
        }

        try {
            for (int i = 0 ; i < 100 ; i++){
                os.println(line);
                os.flush();
                Thread.sleep(1000);
            }
        }
        catch(NullPointerException | IOException | InterruptedException e){
            System.out.println("Client "+line+" Closed");
        }

        finally{    
            try{
                System.out.println("Connection Closing..");

                if(os!=null){
                    os.close();
                    System.out.println("Socket Out Closed");
                }
                if (s!=null){
                s.close();
                System.out.println("Socket Closed");
                }

                }
            catch(IOException ie){
                System.out.println("Socket Close Error");
            }
        }//end finally
    }

When a client connects to the server, the server starts to println. But when the client closes socket, the server still keeps println. Suppose the server will throw exception?

Any help would be appreciated.

Upvotes: 1

Views: 122

Answers (2)

user207421
user207421

Reputation: 311018

  1. PrintWriter swallows exceptions. See the Javadoc.
  2. You will never get an exception on the first write to a connection that has been closed by the peer, for buffering reasons. You will eventually get a 'connection reset'. But never on the first write.
  3. Calling setReuseAddress() after the ServerSocket has been bound is completely pointless, as is calling it inside the loop.

Upvotes: 1

Thanh Duy Ngo
Thanh Duy Ngo

Reputation: 1611

I think you should add ss2.close() and s.close() when you finish the while

while(true){
    try{
    s = ss2.accept();
    ss2.setReuseAddress(true);
    System.out.println("connection Established");
    ServerThread st=new ServerThread(s);
    st.start();
    }
    catch(Exception e){
        e.printStackTrace();
        System.out.println("Connection Error");
     }
 }
 ss2.close();
 s.close();

Upvotes: 0

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