We Keep Coding

Socket Client stuck on 'waiting for message from server.'

Backstory:
I created a Barcode Scanning app that can connect with my works server. The Barcode app functions perfectly, however, I have no experience with socket connections to servers. So in order to not mess up any code in the Barcode app I copied a tutorial for a socket connection and edited it. Once I can get the test code to complete a connection and send data back and forth, I will implement it into the Barcode app.
The Problem:
When I click my button that says "Connect to server" I get this:
03-23 11:55:52.174 6438-6459/com.example.vipin.client I/Client: Waiting for message from server...
Pasted below is the code. I have removed the IP address and Port for security reasons.
package com.example.vipin.client;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Client extends AppCompatActivity implements View.OnClickListener {
public static final String TAG = Client.class.getSimpleName();
public static final int SERVERPORT = 0000;
public static final String SERVER_IP = "000.000.0.0";
ClientThread clientThread;
Thread thread;
TextView messageTv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
messageTv = (TextView) findViewById(R.id.messageTv);
}
public void updateMessage(final String message) {
runOnUiThread(new Runnable() {
#Override
public void run() {
messageTv.append(message + "\n");
}
});
}
#Override
public void onClick(View view) {
if (view.getId() == R.id.connect_server) {
messageTv.setText("");
clientThread = new ClientThread();
thread = new Thread(clientThread);
thread.start();
return;
}
if (view.getId() == R.id.send_data) {
clientThread.sendMessage("Hello from Client");
Log.i(TAG, "Sending message to server...");
}
}
class ClientThread implements Runnable {
private Socket socket;
private BufferedReader input;
#Override
public void run() {
try {
InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
socket = new Socket(serverAddr, SERVERPORT);
while (!Thread.currentThread().isInterrupted()) {
Log.i(TAG, "Waiting for message from server...");
this.input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String message = input.readLine();
Log.i(TAG, "Message received from the server : " + message);
if (null == message || "Disconnect".contentEquals(message)) {
Thread.interrupted();
message = "Server Disconnected.";
updateMessage(getTime() + " | Server : " + message);
break;
}
updateMessage(getTime() + " | Server : " + message);
}
} catch (UnknownHostException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
}
void sendMessage(String message) {
try {
if (null != socket) {
PrintWriter out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())),
true);
out.println(message);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
String getTime() {
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
return sdf.format(new Date());
}
#Override
protected void onDestroy() {
super.onDestroy();
if (null != clientThread) {
clientThread.sendMessage("Disconnect");
clientThread = null;
}
}
}
Log for the button click event is here https://pastebin.com/6wbvLj6w

import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.sql.SQLException;
import javax.imageio.ImageIO;
public class ServerPrintScreen
extends Thread {
private ServerSocket serverSocket;
public ServerPrintScreen(int port)
throws IOException, SQLException, ClassNotFoundException, Exception {
serverSocket = new ServerSocket(port);
serverSocket.setSoTimeout(0);
}
public void run() {
try {
while (true) {
Socket clientSocket = serverSocket.accept();
Throwable localThrowable3 = null;
try {
System.out.println("client connected");
clientSocket.setKeepAlive(true);
String httpResponse = "HTTP/1.1 200 OK\r\nAccess-Control-Allow-Origin: *\r\nAccept-Ranges: bytes\r\nContent-Disposition: inline;filename=screenShot.jpg\r\nContent-Type: image/jpg\r\n\r\n";
BufferedImage originalImage = new Robot().createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
clientSocket.getOutputStream().write(httpResponse.getBytes("UTF-8"));
ImageIO.write(originalImage, "jpg", clientSocket.getOutputStream());
clientSocket.getOutputStream().flush();
clientSocket.getOutputStream().close();
clientSocket.close();
System.out.println("sent");
} catch (Throwable localThrowable1) {
localThrowable3 = localThrowable1;
throw localThrowable1;
} finally {
if (clientSocket != null) {
if (localThrowable3 != null) {
try {
clientSocket.close();
} catch (Throwable localThrowable2) {
localThrowable3.addSuppressed(localThrowable2);
}
} else {
clientSocket.close();
}
}
}
}
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
public static void main(String[] args) throws IOException, SQLException, ClassNotFoundException, Exception {
Thread t = new ServerPrintScreen(25000);
t.start();
}
}

problems with sending String via socket in java

hi everyone i have problems with sending 2 strings via socket in java.
i have UI that get Username and password from client and send it to server . my problem make 2 part :1-i can not get the string username in my server 2- when the client send the username the socket is close before send the password here is my code please help me .
the main purpose is getting 2 string username and password from UI (client)and send them by socket to server.
Server:
package finalproject;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class Server
{
ServerSocket listener;
Socket socket;
OutputStream out ;
InputStream in;;
InputStreamReader reader;
OutputStreamWriter writer;
String massage;
public void connectserver() throws IOException
{
listener = new ServerSocket(9097);
System.out.println("Server is running on port 9097 ...");
}
public void waitforclient() throws IOException
{
socket = listener.accept();
System.out.println("A new client connected to the server");
}
public void startstreamsserver() throws IOException
{
in = socket.getInputStream();
out = socket.getOutputStream();
writer = new OutputStreamWriter(out);
reader = new InputStreamReader(in);
System.out.println("Server streams are ready");
}
public void closestreamsserver() throws IOException
{
writer.close();
reader.close();
}
public void getinfoserver() throws IOException
{
try
{
reader.read();
System.out.println(reader);
System.out.println("input is : " + reader.toString());
}
catch(IOException IOE)
{
IOE.printStackTrace();//if there is an error, print it out
}
}
}
Client:
package finalproject;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Client
{
Socket socket;
OutputStream out1;
InputStream in1;
OutputStreamWriter writer;
InputStreamReader reader;
String massage;
JFrame frame;
BorderLayout blayout;
JButton center;
JButton south;
FlowLayout fLoyout;
JLabel jb1;
JTextField name;
JLabel jb2;
JTextField pass;
JLabel jb7;
JPanel cpanel;
JPanel spanel;
public void connectclient() throws IOException
{
socket = new Socket("localhost", 9097);
System.out.println("connect to server on port 9097");
}
public void startstreamsclient() throws IOException
{
in1 = socket.getInputStream();
out1 = socket.getOutputStream();
writer = new OutputStreamWriter(out1);
reader = new InputStreamReader(in1);
System.out.println("Client streams are ready");
}
public void closestreamsclient() throws IOException
{
writer.close();
reader.close();
}
public void loginformclient()
{
frame = new JFrame();
frame.setVisible(true);
frame.setSize(500, 600);
blayout = new BorderLayout();
center = new JButton();
south = new JButton();
frame.setLayout(blayout);
fLoyout = new FlowLayout(FlowLayout.CENTER);
center.setLayout(fLoyout);
south.setLayout(fLoyout);
jb1 = new JLabel("Username :");
name = new JTextField(20);
center.add(jb1);
center.add(name);
jb2 = new JLabel("Password :");
pass = new JTextField(30);
center.add(jb2);
center.add(pass);
jb7 = new JLabel("Save");
south.add(jb7);
cpanel = new JPanel();
cpanel.add(center);
spanel = new JPanel();
south.addActionListener((ActionEvent ae) -> {
try
{
writer.write(name.getText());
writer.flush();
writer.write(pass.getText());
writer.flush();
writer.close();
}
catch (IOException ex)
{
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
});
spanel.add(south);
cpanel.setLayout(new BoxLayout(cpanel, BoxLayout.Y_AXIS));
frame.add(cpanel, BorderLayout.CENTER);
frame.add(spanel, BorderLayout.SOUTH);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
and my main class :
package finalproject;
import java.io.IOException;
import javax.swing.JFrame;
public class Finalproject
{
public static void main(String[] args) throws IOException
{
//build Server & Client
Server server = new Server();
Client client = new Client();
//Start Server & Client
server.connectserver();
client.connectclient();
//Server wait for new connection
server.waitforclient();
//start the Streams
client.startstreamsclient();
server.startstreamsserver();
//Client send login information to Server
client.loginformclient();
//Server get information
server.getinfoserver();
}
}
but the my inputs in my server are:
java.io.InputStreamReader#171fc7e
input is : java.io.InputStreamReader#171fc7e

Edited Based on EJP correct remark:
Add new line delimiter:
writer.write(name.getText() + System.lineSeparator());
writer.write(pass.getText());
writer.flush();
replace this:
reader = new InputStreamReader(in);
System.out.println("Server streams are ready");
with:
BufferedReader in = new BufferedReader(reader);
String username= in.readLine();
String password = in.readLine();

Can't set ImageView photo from datainputstream JavaFx socket application

I am trying to output an image to an ImageView in javafx, i am recieving the image via socket connection and saving it to my hard-drive then i create an Image object with the path of the newly created image, the problem is that the image view is not updated.
public void save(String path, DataInputStream dis) throws IOException {
FileOutputStream fos = new FileOutputStream("src/img"+(frame_number)+".jpg");
//Image imBuff = ImageIO.read(socket.getInputStream());
int filesize = dis.readInt(); // Send file size in separate msg
byte[] buffer = new byte[filesize];
int read = 0;
int totalRead = 0;
int remaining = filesize;
while ((read = dis.read(buffer, 0, Math.min(buffer.length, remaining))) >= 1) {
totalRead += read;
remaining -= read;
//System.out.println("read " + totalRead + " bytes.");
fos.write(buffer, 0, read);
System.err.println("img"+(frame_number)+".jpg");
fos.flush();
}
fos.flush();
fos.close();
System.out.println("frame num:"+frame_number);
Image i = new Image("Camera_Frame.jpg");
try{
//i=new Image("img"+frame_number+".jpg");
File f = new File("img"+frame_number+".jpg");
i = new Image(f.toURI().toString());
iv.setImage(i);
}catch(Exception e){
System.out.println("didn't find");
}
System.out.println("stream size:"+image_Stream.size());
ps.println("ok");
frame_number++;
}
Things i have tried:
1- i tried to used the path i saved the photo in to create an Image then used the setImage() function on my ImageView (iv), i got Invalid Url even though i loaded an image image from the same directory before.
2- we tried using (file:///) to get an absolute path but it didn't work, also invalid url
3- i tried loading the image as a file first then using the toURI() function to get the proper path to it then create an image accordingly, i don't get an error but it also doesn't update the UI
P.S
this function is called in a sub Thread that updates an ImageView in the main javafx thread, i tried it with images not loaded through the socket connection and it worked, but when i try to display the images i receive the face this problem.
EDIT: I managed to load the image properly, now i can't update the ImageView using iv.setImage()
EDIT:
CameraOBJ class
import java.awt.image.BufferedImage;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
import javax.imageio.ImageIO;
import javafx.animation.AnimationTimer;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Platform;
import javafx.geometry.Pos;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.stage.FileChooser;
import javafx.util.Duration;
public class CameraOBJ implements Runnable{
String name;
int delay;
Socket socket;
String ip;
int port;
PrintStream ps;
Scanner sc;
static int frame_number;
StackPane sp;
Label delay_lbl;
ImageView iv;
public CameraOBJ (String name, String ip, int port){
this.ip = ip;
this.port = port;
this.name = name;
sp = new StackPane();
}
public void run() {
setStackPane();
connect();
while(true){
update();
}
// Timeline timeline = new Timeline();
// Duration duration = Duration.seconds(1/Settings.FPS);
// KeyFrame f1 = new KeyFrame(duration,e->{
// update();
// });
// timeline.getKeyFrames().add(f1);
// timeline.setCycleCount(Timeline.INDEFINITE);
// timeline.play();
}
private void update() {
// Platform.runLater(new Runnable() {
// public void run() {
DataInputStream dis;
try {
dis = new DataInputStream(socket.getInputStream());
if(dis!=null){
save("images",dis);
//setStackPane();
}
} catch (IOException e1) {
System.out.println(e1.getMessage());
}
// }
// });
}
public void setStackPane(){
Platform.runLater(new Runnable() {
public void run() {
sp.setMinSize(500, 384);
sp.setMaxSize(500, 384);
sp.setStyle("-fx-background-color: #FFFFFF;");
Image image = new Image("Camera_Frame.jpg");
iv = new ImageView(image);
iv.setFitWidth(470);
iv.setPreserveRatio(true);
Label name_lbl = new Label(name);
delay_lbl = new Label(delay+"");
sp.setAlignment(iv,Pos.CENTER);
sp.setAlignment(name_lbl,Pos.TOP_LEFT);
sp.setAlignment(delay_lbl,Pos.BOTTOM_RIGHT);
sp.getChildren().addAll(iv,name_lbl,delay_lbl);
}
});
}
public void connect(){
try{
socket = new Socket(ip, port);
System.out.println(socket.isConnected());
ps = new PrintStream(socket.getOutputStream());
sc = new Scanner(socket.getInputStream());
}
catch (Exception c){
c.getMessage();
}
}
public void save(String path, DataInputStream dis) throws IOException {
Platform.runLater(new Runnable() {
public void run() {
FileOutputStream fos;
try {
fos = new FileOutputStream("src/img"+(frame_number)+".jpg");
int filesize;
try {
filesize = dis.readInt();
byte[] buffer = new byte[filesize];
int read = 0;
int totalRead = 0;
int remaining = filesize;
while ((read = dis.read(buffer, 0, Math.min(buffer.length, remaining))) >= 1) {
totalRead += read;
remaining -= read;
//System.out.println("read " + totalRead + " bytes.");
fos.write(buffer, 0, read);
System.err.println("img"+(frame_number)+".jpg");
fos.flush();
}
fos.flush();
fos.close();
} catch (IOException e1) {
e1.printStackTrace();
}
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
System.out.println("frame num:"+frame_number);
Image i = new Image("Camera_Frame.jpg");
try{
//i=new Image("file:img"+frame_number+".jpg");
File f = new File("C:\\Users\\ahmed\\workspace\\College\\RTS_Client\\src\\img"+frame_number+".jpg");
i = new Image(f.toURI().toString());
iv.setImage(i);
delay_lbl.setText("frame_number: "+frame_number);
}catch(Exception e){
System.out.println("didn't find");
}
frame_number++;
}
});
}
}
Main class:
import java.io.File;
import java.io.PrintStream;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import com.sun.prism.paint.Color;
import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;
import javafx.scene.image.ImageView;
import javafx.scene.layout.Background;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.FileChooser;
import javafx.stage.Modality;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
public class main extends Application{
static Stage window;
static String default_ip = "192.168.43.200";
static int default_port = 1234;
public static void main(String[] args) {
launch(args);
}
public void start(Stage stage) {
window = stage;
window.setResizable(false);
window.setTitle("Control Room");
StackPane sp = new StackPane();
sp.setMinSize(500, 500);
Scene sc = new Scene(sp);
window.setScene(sc);
window.show();
CameraOBJ camera = new CameraOBJ("Camera 1", default_ip, default_port);
Thread t = new Thread(camera);
camera.run();
sc = new Scene(camera.sp);
window.setScene(sc);
}
}
Server class:
import java.io.IOException;
import java.io.PrintStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.InputMismatchException;
import java.util.NoSuchElementException;
import java.util.Scanner;
public class Camera implements Runnable {
long timeStamp;
int delayShift;
int FPS;
boolean idle;
//Control Rooms object here
int portNumber;
Socket csocket;
Camera() {
}
Camera(Socket csocket) {
this.csocket = csocket;
}
void startConnection() throws Exception {
ServerSocket ssock = new ServerSocket(1234);
System.out.println("Listening");
while (true) {
Socket sock = ssock.accept();
System.out.println("Connected");
new Thread(new Camera(sock)).start();
}
}
public void run() {//Start Stream
try {
PrintStream pstream = new PrintStream(csocket.getOutputStream());
Scanner inpstream = new Scanner(csocket.getInputStream());
// Receiving an integer that is sent from the client side.
int ID = inpstream.nextInt();
// Generating a reply based on the ID sent from the client.
String response = "";
if (ID == 1100) {
response = "Your name is Mahmoud. \n" + "You are 22 years old.";
} else {
response = "No data found matching the ID you entered.";
}
// Sending the reply through the OutputStream to the client.
pstream.println(response);
pstream.close();
terminateConnection();
} catch (InputMismatchException e) {
System.out.println(e.toString() + "\nNo data is received.");
} catch (IOException e) {
System.out.println(e.toString());
} catch (Exception c) {
System.out.println(c.toString());
}
}
void terminateConnection() throws IOException {
csocket.close();
}
public static void main(String[] args) throws Exception {
Camera cam = new Camera();
cam.startConnection();
}
}

Multi-client chat program, broadcasting chat to all clients?

I'm trying to make a very simple chat program that can accommodate multiple clients. I have a multi-threaded server and can connect multiple clients to it, but the server only communicates with a single client (as it should, each client is on its own thread) I need help getting the server to send all messages from all connected clients to each client. I think I'd need to share a single object between threads? Here's the code:
server:
import java.net.ServerSocket;
import java.net.Socket;
public class ThreadedCommandServer {
public static void main(String[] args) throws Exception {
System.out.println("Starting server....");
int port = 8989;
ServerSocket ss = new ServerSocket(port);
while(true) {
System.out.println("Waiting for connection from client...");
Socket socket = ss.accept();
ServerThread st = new ServerThread(socket);
st.start();
}
}
}
server thread:
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
public class ServerThread extends Thread {
private Socket socket = null;
private String s;
public ServerThread(Socket s) {
socket = s;
}
public void run() {
try {
InputStream is = socket.getInputStream();
ObjectInputStream ois = new ObjectInputStream(is);
s = (String) ois.readObject();
System.out.println("received string: " + s);
OutputStream os = socket.getOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
oos.writeObject(s);
System.out.println("sent object back to client...");
} catch (Exception e) {
System.out.println(e.toString());
}
}
}
client:
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
public class Controller {
private ClientFrame cf;
private String message;
private Socket socket;
private String response;
public Controller(ClientFrame cf) {
this.cf = cf;
}
public void sendChat(String s) {
message = s;
System.out.println("FROM CONTROLLER: received: " + message);
try {
InetAddress i = InetAddress.getByName("localhost");
socket= new Socket(i, 8989);
OutputStream os = socket.getOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
System.out.println("FROM CONTROLLER: sending message to the server...");
oos.writeObject(message);
InputStream is = socket.getInputStream();
ObjectInputStream ois = new ObjectInputStream(is);
System.out.println("getting string back from server....");
response = (String) ois.readObject();
cf.updateGUI(response);
}
catch (Exception e) {
e.printStackTrace();
}
}
}
GUI:
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class ClientFrame extends JFrame {
private JTextArea chatArea;
private JTextField type;
private JButton submit;
private JPanel upper;
private JPanel lower;
private BorderLayout bl;
JScrollPane jsp;
Controller c;
public ClientFrame() {
bl = new BorderLayout();
upper = new JPanel();
lower = new JPanel();
chatArea = new JTextArea("chat goes here", 20, 30);
c = new Controller(this);
chatArea.setEditable(false);
chatArea.setLineWrap(true);
type = new JTextField("type here", 20);
jsp = new JScrollPane(chatArea);
new SmartScroller(jsp);
lower.add(type);
submit = new JButton("send");
submit.addActionListener(new Submit());
type.addActionListener(new Submit());
lower.add(submit);
upper.add(jsp);
this.setSize(400, 600);
this.setLayout(bl);
this.setTitle("MattChatt");
this.add(upper, BorderLayout.NORTH);
this.add(lower, BorderLayout.SOUTH);
this.setVisible(true);
this.setResizable(false);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public void updateGUI(String s) {
chatArea.append("\n" + s);
}
private class Submit implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if (type.getText().equals("")) {
System.out.println("no text entered");
} else {
System.out.println("submitted");
c.sendChat(type.getText());
type.setText("");
}
}
}
}

You have no way of accessing all of the ServerThreads you create.
What you need to do is group them all together in a collection, such as an ArrayList.
Or even better, a HashMap, if you would ever want to expand your application to allow private messaging, you would need to access a specific ServerThread, and with a HashMap you can do so easily.
Anyways... when it is time to send out the message, you should loop your collection through and send the message to the OutputStreams associated with each ServerThread.

Android tcp client connects then disconnect from java server

I am doing java server on my pc and having my android device connect to it. I can connect it but it disconnects as soon as it connects. I am sure there is something I need to do on the android side but I am little lost on it. I have the internet permission so that is fine.
Also ignore the commented code I was sending image from my android to pc. Also ignore the savebitmap and take screenshot I don't think its affecting the connection if its not being called.
Java Server:
import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import javax.swing.*; //access JFrame
import javax.swing.text.html.HTMLDocument.Iterator;
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.*;
public class tcpmain {
BufferedReader in;
static final int PORT = 9000;
public static void main(String[] args) {
// TODO Auto-generated method stub
//lines to make the gui frame
JFrame mainframe = new JFrame();
mainframe.setTitle("TCP Listener");
mainframe.setSize(600,800);
mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainframe.setVisible(true);
ServerSocket serverSocket = null;
Socket socket = null;
try{
serverSocket = new ServerSocket(PORT);
//Receive code
/*int filesize=450660;
int bytesRead;
int current=0;
//receive file
byte [] mybytearray = new byte [filesize];
InputStream is = srsvsock.getInputStream();
FileOutputStream fos = new FileOutputStream("C:\\Users\\Andy\\Desktop\\testimage.jpg");
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead;*/
/*do{
bytesRead =
is.read(mybytearray, current, (mybytearray.length-current));
if(bytesRead >= 0) current += bytesRead;
} while(bytesRead > -1);
bos.write(mybytearray, 0, current);
bos.flush();*/
}
catch(Exception e){
e.printStackTrace();
}
while (true) {
try {
socket = serverSocket.accept();
JOptionPane.showMessageDialog(null, "Client connected", "ALERT", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException e) {
System.out.println("I/O error: " + e);
}
// new threa for a client
new EchoThread(socket).start();
if ( socket != null && !socket.isClosed() ){
try {
socket.close();
JOptionPane.showMessageDialog(null, "Client Disconnected", "ALERT", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
client handler for java server
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.Socket;
public class EchoThread extends Thread {
protected Socket socket;
public EchoThread(Socket clientSocket){
this.socket = clientSocket;
}
public void run(){
InputStream inp = null;
BufferedReader brinp = null;
DataOutputStream out = null;
try{
inp = socket.getInputStream();
brinp = new BufferedReader(new InputStreamReader(inp));
out = new DataOutputStream(socket.getOutputStream());
}catch(Exception e){
return;
}
String line;
while(true){
try{
line = brinp.readLine();
if ((line == null) || line.equalsIgnoreCase("QUIT")){
socket.close();
return;
}else{
out.writeBytes(line+ "\n\r");
out.flush();
}
}catch(Exception e){
e.printStackTrace();
return;
}
}
}
}
Here is android client:
package com.example.tcpsocket;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
private Socket socket;
private static final int SERVERPORT = 9000;
private static final String SERVER_IP = "192.168.1.113";
Bitmap bitmap;
File imagePath;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnconnect = (Button)findViewById(R.id.button1);
btnconnect.setOnClickListener(connect);
}
private OnClickListener connect = new OnClickListener(){
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
//Bitmap bitmap = takeScreenshot();
// saveBitmap(bitmap);
new Thread(new clienthread()).start();
}
};
public Bitmap takeScreenshot() {
View rootView = findViewById(android.R.id.content).getRootView();
rootView.setDrawingCacheEnabled(true);
return rootView.getDrawingCache();
}
public void saveBitmap(Bitmap bitmap){
File imagePath = new File("sdcard/screenshot.jpg");
FileOutputStream fos;
try {
fos = new FileOutputStream(imagePath);
bitmap.compress(CompressFormat.JPEG, 100, fos);
fos.flush();
fos.close();
new Thread(new clienthread()).start();
} catch (FileNotFoundException e) {
Log.e("GREC", e.getMessage(), e);
} catch (IOException e) {
Log.e("GREC", e.getMessage(), e);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
class clienthread implements Runnable {
#Override
public void run() {
// TODO Auto-generated method stub
try{
InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
socket = new Socket(serverAddr, SERVERPORT);
/*File imagePath = new File("sdcard/screenshot.jpg");
byte[] mybytearray = new byte[450560];
FileInputStream fis = new FileInputStream(imagePath);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
OutputStream os = socket.getOutputStream();
os.write(mybytearray,0,mybytearray.length);
os.close();*/
}
catch(Exception e){
}
}
}
}

Here:
new EchoThread(socket).start();
if ( socket != null && !socket.isClosed() ){
try {
socket.close();//Don't do this here!!!!!!
JOptionPane.showMessageDialog(null, "Client Disconnected", "ALERT", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
You shouldn't close your socket after you started your Thread. The closing of the socket should be the job of the EchoThread after you finished communicating with it. You can insert this line at the end of run() method socket.close(); so it closes itself when you're done.

Looks like it is most likely due to this line:
if ( socket != null && !socket.isClosed() ){
If your socket was previously opened and you passed if off to the thread to handle, the socket would still be open and socket.isClosed() will return false and you'll immediately close the socket and clean it up in your main thread.