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POJava-server can't send message to Android client
 

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  1. POJava-server can't send message to Android client
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    <p>I am new for TCP protocol in Java. I want to make a server-client chatting interface. I can able to send the messages from client to server but when I send message from server to client then my android app crash suddenly. Here is my code..for Android Client..</p> <pre><code>public class chatWithServer extends Fragment { private ListView mList; private ArrayList&lt;String&gt; arrayList; private MyCustomAdapter mAdapter; Button send; EditText editText; String serverMessage; PrintWriter out; BufferedReader in; private static final String HOST = "192.168.48.1"; private static final int PORT = 5000; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { //super.onCreate(savedInstanceState); final View myFragmentView = inflater.inflate( R.layout.activity_main, container, false); arrayList = new ArrayList&lt;String&gt;(); editText = (EditText)myFragmentView. findViewById(R.id.editText); send = (Button)myFragmentView.findViewById(R.id.send_button); send.setOnClickListener(onClickSend(myFragmentView)); //relate the listView from java to the one created in xml mList = (ListView)myFragmentView.findViewById(R.id.list); mAdapter = new MyCustomAdapter(getActivity(), arrayList); mList.setAdapter(mAdapter); connectServerTask(); return myFragmentView; } //--------&gt;By clicking Send Button&lt;---------////// private OnClickListener onClickSend(final View myFragmentView) { return new OnClickListener() { @Override public void onClick(View v) { String message = editText.getText().toString(); //add the text in the arrayList arrayList.add("c: " + message); //sends the message to the server sendToServer(message); //refresh the list mAdapter.notifyDataSetChanged(); editText.setText(""); } }; } private void connectServerTask() { Runnable runnable= new Runnable() { @Override public void run() { setSocket(); } private void setSocket() { try { // Create Socket instance Socket socket = new Socket(HOST, PORT); out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true); out.println("Connected to Client"); try{ in = new BufferedReader(new InputStreamReader(socket.getInputStream())); serverMessage =in.readLine(); if(serverMessage!=null) { //sends the message to the server chatUp(serverMessage); } serverMessage=null; } catch (UnknownHostException e) { e.printStackTrace(); } finally{ socket.close(); } }catch (IOException e) { e.printStackTrace(); } } private void chatUp(String message) { arrayList.add(message); mAdapter.notifyDataSetChanged(); } }; new Thread(runnable).start(); } //method of sending message to server public void sendToServer(String message){ if (out != null &amp;&amp; !out.checkError()) { out.println(message); out.flush(); }; } } Here is the code for Java-Server public class TCPServer extends Thread { public static final int SERVERPORT = 5000; private boolean running = false; private PrintWriter mOut; private OnMessageReceived messageListener; public static void main(String[] args) { //opens the window where the messages will be received and sent ServerBoard frame = new ServerBoard(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setVisible(true); } /** * Constructor of the class * @param messageListener listens for the messages */ public TCPServer(OnMessageReceived messageListener) { this.messageListener = messageListener; } /** * Method to send the messages from server to client * @param message the message sent by the server */ public void sendMessage(String message){ if (mOut != null &amp;&amp; !mOut.checkError()) { mOut.println(message); mOut.flush(); } } @SuppressWarnings("resource") @Override public void run() { super.run(); running = true; try { System.out.println("S: Connecting..."); //create a server socket. A server socket waits for requests to come in over the network. ServerSocket serverSocket = new ServerSocket(SERVERPORT); //create client socket... the method accept() listens for a connection to be made to this socket and accepts it. Socket client = serverSocket.accept(); System.out.println("S: Receiving..."); try { //sends the message to the client mOut = new PrintWriter(new BufferedWriter(new OutputStreamWriter(client.getOutputStream())), true); //read the message received from client BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream())); //in this while we wait to receive messages from client (it's an infinite loop) //this while it's like a listener for messages while (running) { String message = in.readLine(); if (message != null &amp;&amp; messageListener != null) { //call the method messageReceived from ServerBoard class messageListener.messageReceived(message); } } } catch (Exception e) { System.out.println("S: Error"); e.printStackTrace(); } finally { client.close(); System.out.println("S: Done."); } } catch (Exception e) { System.out.println("S: Error"); e.printStackTrace(); } } //Declare the interface. The method messageReceived(String message) will must be implemented in the ServerBoard //class at on startServer button click public interface OnMessageReceived { public void messageReceived(String message); } } </code></pre> <p>ServerBoard.java(for server)</p> <pre><code>public class ServerBoard extends JFrame {//jFrame is for the desplaying the window and for nice GUI private JTextArea messagesArea;//A JTextArea is a multi-line area that displays plain text. private JButton sendButton; private JTextField message;//JTextField is a lightweight component that allows the editing of a single line of text. private JButton startServer; private TCPServer mServer; public ServerBoard() { super("ServerBoard"); JPanel panelFields = new JPanel(); panelFields.setLayout(new BoxLayout(panelFields,BoxLayout.X_AXIS)); JPanel panelFields2 = new JPanel(); panelFields2.setLayout(new BoxLayout(panelFields2,BoxLayout.X_AXIS)); //here we will have the text messages screen messagesArea = new JTextArea(); messagesArea.setColumns(30); messagesArea.setRows(10); messagesArea.setEditable(false); sendButton = new JButton("Send"); sendButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // get the message from the text view String messageText = message.getText(); // add message to the message area messagesArea.append("\n" + messageText); // send the message to the client mServer.sendMessage(messageText); // clear text message.setText(""); } }); startServer = new JButton("Start"); startServer.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // disable the start button startServer.setEnabled(false); //creates the object OnMessageReceived asked by the TCPServer constructor mServer = new TCPServer(new TCPServer.OnMessageReceived() { @Override //this method declared in the interface from TCPServer class is implemented here //this method is actually a callback method, because it will run every time when it will be called from //TCPServer class (at while) public void messageReceived(String message) { messagesArea.append("\n "+message); } }); mServer.start(); } }); //the box where the user enters the text (EditText is called in Android) message = new JTextField(); message.setSize(200, 20); //add the buttons and the text fields to the panel panelFields.add(messagesArea); panelFields.add(startServer); panelFields2.add(message); panelFields2.add(sendButton); getContentPane().add(panelFields); getContentPane().add(panelFields2); getContentPane().setLayout(new BoxLayout(getContentPane(),BoxLayout.Y_AXIS)); setSize(300, 170); setVisible(true); } } </code></pre> <p>--Edited--</p> <pre><code>10-24 17:04:07.039: E/AndroidRuntime(15911): FATAL EXCEPTION: Thread-1131 10-24 17:04:07.039: E/AndroidRuntime(15911): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views. 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5908) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:837) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.view.View.requestLayout(View.java:15792) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.widget.AbsListView.requestLayout(AbsListView.java:1837) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.widget.AdapterView$AdapterDataSetObserver.onChanged(AdapterView.java:813) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.widget.AbsListView$AdapterDataSetObserver.onChanged(AbsListView.java:5998) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.database.DataSetObservable.notifyChanged(DataSetObservable.java:37) 10-24 17:04:07.039: E/AndroidRuntime(15911): at android.widget.BaseAdapter.notifyDataSetChanged(BaseAdapter.java:50) 10-24 17:04:07.039: E/AndroidRuntime(15911): at com.example.cardioapp.database.chatWithServer$2.display(chatWithServer.java:142) 10-24 17:04:07.039: E/AndroidRuntime(15911): at com.example.cardioapp.database.chatWithServer$2.setSocket(chatWithServer.java:123) 10-24 17:04:07.039: E/AndroidRuntime(15911): at com.example.cardioapp.database.chatWithServer$2.run(chatWithServer.java:94) 10-24 17:04:07.039: E/AndroidRuntime(15911): at java.lang.Thread.run(Thread.java:841) </code></pre>
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    1. USHiren
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    1. COPlease post the error output that you get.
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    2. COThis is not a networking question. Please read your error output.
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