Properly disconnect client (telnet) from ServerSocket

Question

I want a simple server socket to accept a client and read some texts and disconnect the client from itself. As a client I'm using a telnet for now, because in the future I will create a custom program.

    ServerSocket ss = new ServerSocket(SERVER_SOCKET_PORT); 
    Socket s = ss.accept();

    BufferedReader reader = new BufferedReader(new InputStreamReader(s.getInputStream()));
    String line;
    while (true) {
        line = reader.readLine();
        if (line == null || line == "" || line == "q") {
            log("-- breaking the loop");
            break;
        }

        printf("**%s%n", line);
    }
    reader.close();
    s.close();
    ss.close();

The problem I'm having is the while loop never breaks.

Answer 1

First, that isn't how you compare String(s) for equality. Second, I would prefer String.isEmpty() to testing for equality with "". Finally, you can use a try-with-resources to close everything. Something like,

try (ServerSocket ss = new ServerSocket(SERVER_SOCKET_PORT);
        Socket s = ss.accept();
        BufferedReader reader = new BufferedReader(
                new InputStreamReader(s.getInputStream()))) {
    String line;
    while ((line = reader.readLine()) != null) {
        if (line.isEmpty() || line.equalsIgnoreCase("q")) {
            System.out.println("-- breaking the loop");
            break;
        }

        System.out.printf("**%s%n", line);
    }
} catch (Exception e) {
    e.printStackTrace();
}