Question

This is a client part of programm.
I have such class which works with sockets and has methods to read and write to server
How can I make an event to catch messages from server?
Some actionListener which makes actions only when thereis a message in inputStream.
I’ve tried timer which calls Running.receiveLine(); but it works very bad.
The solution with while(true) also seems to be not good.

public class Running extends Thread{
private Socket s;
private PrintStream ps;
private BufferedReader br;

public Running(){
try{
    s = new Socket(InetAddress.getLocalHost(), 8072);
    ps = new PrintStream(s.getOutputStream());
    br = new BufferedReader(new InputStreamReader(s.getInputStream()));
} catch (UnknownHostException ex) {
    System.out.println("11");
    ex.printStackTrace();
} catch (IOException ex) {
    System.out.println("00");
    ex.printStackTrace();
}
}

public String receiveLine(){
    String ret = "";
    try {
        ret = br.readLine();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return ret;
}

public void sendLine(String s){
    ps.println(s);
}

public void close(){
    try {
        s.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
  }

Answer 1

I think it’s not a problem to use method read() because it blocks flow until new portion of data is available. All standard Java input streams have a good implementation of this approach, based on monitors. So your thread won’t eat CPU and other resources during waiting.

Also you can refer to non-blocking IO in Java NIO.

Small addition.
To use it with Swing you can use queue approach in fusion with SwingWorker.