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POClient-Server TCP communication
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copied!<p>The server should send a message "Hello :: enter QUIT to exit" to the client, then the client types in any text and the server echos back the client's text adding "From server: " before their message. But there seems to be a mix up in the order and I can't seem to find where! I've been on this all day! </p> <p>This is the Server's code:</p> <pre><code> import java.net.*; public class Server { public static void main(String[] args) { int nreq = 1; try { ServerSocket sock = new ServerSocket (8080); for (;;) { Socket newsock = sock.accept(); System.out.println("Creating thread ..."); Thread t = new ThreadHandler(newsock,nreq); t.start(); } } catch (Exception e) { System.out.println("IO error " + e); } System.out.println("End!"); } } </code></pre> <p>ThreadHandler code:</p> <pre><code> import java.io.*; import java.net.*; class ThreadHandler extends Thread { Socket newsock; int n; ThreadHandler(Socket s, int v) { newsock = s; n = v; } // @SuppressWarnings("deprecation") public void run() { try { PrintWriter outp = new PrintWriter(newsock.getOutputStream(), true); BufferedReader inp = new BufferedReader(new InputStreamReader( newsock.getInputStream())); outp.println("Hello :: enter QUIT to exit"); boolean more_data = true; String line; while (more_data) { line = inp.readLine(); if (line == null) { more_data = false; } else { outp.println("From server: " + line + "\n"); if (line.trim().equals("QUIT")) more_data = false; } } newsock.close(); } catch (Exception e) { System.out.println("IO error " + e); } } } </code></pre> <p>And the Client code:</p> <pre><code> import java.io.*; import java.net.*; import java.util.Scanner; public class Client { // @SuppressWarnings("deprecation") public static void main(String args[]) { Scanner scanner = new Scanner(System.in); try { Socket s = new Socket("localhost", 8080); PrintWriter outp = new PrintWriter(s.getOutputStream(), true); BufferedReader inp = new BufferedReader(new InputStreamReader( s.getInputStream())); boolean more_data = true; System.out.println("Established connection"); String line; while (more_data) { line = inp.readLine(); String userInput = scanner.nextLine(); outp.println(userInput); if (line == null) { more_data = false; } else System.out.println(line); } System.out.println("end of while"); } catch (Exception e) { System.out.println("IO error " + e); } } } </code></pre> <p>I'm testing it out so after I'm going to make the client an Android phone - if that's possible -</p> <hr> <p>Update:</p> <p>I've changed the server's code to:</p> <pre><code>outp.println("Hello :: enter QUIT to exit \n"); boolean more_data = true; String line; while (more_data) { line = inp.readLine(); System.out.println("Message '" + line + "' echoed back to client.");// !! if (line == null) { System.out.println("line = null"); more_data = false; } else { outp.println("From server: " + line + ". \n"); if (line.trim().equals("QUIT")) more_data = false; } } newsock.close(); System.out.println("Disconnected from client number: " + n); </code></pre> <p>and added "\n" at the end of the Hello message as Luis Miguel Serrano suggested, And changed the Client's side as below:</p> <pre><code>boolean more_data = true; System.out.println("Established connection"); String line;// = inp.readLine(); while (more_data) { line = inp.readLine(); System.out.println(line); if (line == null) { // nothing read more_data = false; } else line = inp.readLine(); System.out.println(line); String userInput = scanner.nextLine(); if (userInput.trim() == "QUIT") { s.close(); System.out.println("Disconnected from server."); more_data = false; } else outp.println(userInput); } System.out.println("end of while"); </code></pre> <p>And it works fine now.</p> <p><strong>If anyone could suggest me some Android client-java server tutorials would appreciate it.</strong></p>

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