java socket server, client detect server has died

Question

If I kill the Socket Server process, my Socket client process does not receive any errors, it continues to loop forever on the following code:

public void run() {
    while(readData) {
      String inputLine = null;
      try {
        while((inputLine = m_inputStream.readLine()) != null) {
          //do stuff
        }
      } catch (IOException e) {
         readData = false;
     }
  }
}

How can I detect that the socket server is gone and terminate the loop?

Answer 1

Terminate the outer loop when the call to readLine() returns null.

No exception is thrown when the server closes the connection normally. The stream should return null to signal the end of data.

This can be done with a loop like this:

public void run() {
  try {
    while (true) {
      String line = input.readLine();
      if (line == null)
        break;
      /* Process line. */
      ...
    }
  } catch (IOException ex) {
    /* Handle the exception as desired. */
    ex.printStackTrace();
  }
}