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Wait for client to enter name before broadcasting the server message

From GameServer.java:
while (true) {
Socket clientSocket = serverSocket.accept();
PlayerThread playerThread = new PlayerThread(clientSocket, this);
playerThreads.add(playerThread);
playerThread.start();
if (playerThreads.size() == maxPlayers) {
broadcast("All players have joined! Let the game begin!", null);
}
}
From PlayerThread.java:
#Override
public void run() {
try {
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(socket.getOutputStream(), true);
out.println("What's your name? ");
String userName = in.readLine();
Player player = new Player(userName);
gameServer.addPlayer(p);
String clientMove;
while ((clientMove = in.readLine()) != null) {
gameServer.makeMove(player, clientMove);
gameServer.broadcast(p.getName() + " made the move: " + clientMove, this);
}
} catch (IOException e) {
e.printStackTrace();
}
}
Starting the server:
Client1 at the end:
Client2 at the end:
How do I wait for the last client (here, client2) to enter their name before broadcasting the message?
Here's the broadcast function:
public void broadcast(String message, PlayerThread excluded) {
for (PlayerThread p : playerThreads) {
if (p != excluded)
p.sendMessage(message);
}
}

Use CountDownLatch:
private CountDownLatch countDownLatch = new CountDownLatch(maxPlayers);
So, after playerThreads.size() == maxPlayers reached, call await:
if (playerThreads.size() == maxPlayers) {
countDownLatch.await();
broadcast("All players have joined! Let the game begin!", null);
}
You need to pass this CountDownLatch to every PlayThread, and after username is read, call CountDownLatch#countDown:
public PlayerThread(Socket socket, GameServer gameServer, CountDownLatch countDownLatch) throws IOException {
downLatch = countDownLatch;
}
#Override
public void run() {
try {
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(socket.getOutputStream(), true);
out.println("What's your name? ");
String userName = in.readLine();
downLatch.countDown();
} catch (IOException e) {
e.printStackTrace();
}
}

JAVA Socket object + text

Does it possible, to get from client and
objetObjectInputStream
and
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
for example, some client send me tet message, and someone send files. Should I make a new socket server for each?
public class ServerRequests {
Connection con = new Connection();
private Socket socket;
private BufferedReader in;
private BufferedWriter out;
public ServerRequests(Socket socket) throws IOException {
this.socket = socket;
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
run();
}
public void run() {
String word;
try {
String object;
ObjectInputStream obIn = new ObjectInputStream(socket.getInputStream());
while ((object = (String) obIn.readObject()) != null){
if (object.contains("F47S")){
String[] result = object.split(":");
String fileName = result[1];
String url = result[2];
String culture = result[3];
System.out.println("FileName:" +fileName);
System.out.println("url:" +url);
FileOutputStream outOb = null;
if(culture.contains("test")) {
outOb = new FileOutputStream(fileName);
}
DataInputStream inOb = new DataInputStream(socket.getInputStream());
byte[] bytes = new byte[5*1024];
int count, total=0;
long lenght = inOb.readLong();
while ((count = inOb.read(bytes)) > -1) {
total+=count;
outOb.write(bytes, 0, count);
if (total==lenght) break;
}
outOb.close();
}
}
}catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
// while (true) {
word = in.readLine();
System.out.println(word);
if (word != null) {
String[] result = word.split(":");
String type = result[0];
if (type.contains("AUTH")) {
String login = result[2];
String pass = result[4];
String gui = con.checkLogin(pass, login);
auth(gui);
}
} catch (IOException e) {
}
}
private void auth(String gui) {
try {
out.write(gui + "\n");
out.flush();
} catch (IOException ignored) {
}
}
private void success(String status) {
try {
out.write(status+ "\n");
out.flush();
} catch (IOException ignored) {
}
}
}

Java how do I use an incoming socket from the client several times

So my question is when a socket connects is it possible to create two datainputstreams which both reference to 1 socket inputstream. I would like to print out text and text2 but this does not work.
Client code
public static void main(String[] args) {
new Sender();
}
public Sender() {
try {
Socket sock = new Socket("127.0.0.1",1337);
DataOutputStream out = new DataOutputStream(sock.getOutputStream());
out.writeUTF("Test");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Server code
public static void main(String[] args) {
new Listen();
}
public Listen() {
Thread thread = new Thread(this);
thread.start();
}
#Override
public void run() {
try {
ServerSocket serversocket = new ServerSocket(1337);
while(true) {
Socket socket = serversocket.accept();
System.out.println(socket.getPort() + ": " + socket.getInetAddress().getHostAddress());
DataInputStream input = new DataInputStream(socket.getInputStream());
DataInputStream input2 = new DataInputStream(socket.getInputStream());
String text = input.readUTF();
String text2 = input2.readUTF();
if(text != null) {
System.out.println(text);
}
if(text2 != null) {
System.out.println(text2);
}
//socket.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("Error");
}

You need a loop, that terminates on EOFException. And don't write code like this. Code that depends on the success of code in a prior try block should be inside that try block.
input = new DataInputStream(socket.getInputStream());
while(!formclosed) {
try {
String addtext = input.readUTF();
addtext = formatText(addtext);
logarea.setText(logarea.getText() + addtext);
} catch (EOFException e) {
System.out.println("Client has disconnected.");
return;
}
}
// any other IOException should be treated as an error
This should run as a background thread, not when you press a button.

android.os.NetworkOnMainThreadException but my class extends Thread

I have a client class that extends Thread to start socket programming
my class code
class MyClientMessages extends Thread {
Socket socket;
int PORT = 5002;
DataInputStream din;
DataOutputStream dout;
public MyClientMessages(String IP) {
try {
System.out.println("IP = ======= " + IP + " TYPE = " + TYPE);
//*********** crash here ***************
socket = new Socket(IP,PORT); // *********** it crash here *************
din = new DataInputStream(socket.getInputStream());
dout = new DataOutputStream(socket.getOutputStream());
this.start();
}catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void run() {
while (true) {
byte[] data = new byte[1024];
int size = 0;
try {
while ((size = din.read(data)) > 0) {
final String str = new String(data,"UTF8");
runOnUiThread(new Runnable() {
#Override
public void run() {
TextView textView = new TextView(ServerChat.this);
textView.setTextSize(15);
textView.setText(str);
linearLayout.addView(textView);
}
});
}
}catch (IOException e) {
e.printStackTrace();
try {
dout.close();
din.close();
socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
public void WriteToSocket(byte[] arr,int size) {
try {
dout.write(arr,0,size);
dout.flush();
}catch (IOException e) {
e.printStackTrace();
try {
dout.close();
din.close();
socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
I make this class inside my activity class. I have another class inside my activity class for server, which extends thread and it works fine. Why does this client class crash and give me this error ?
this how I use it on my onCreate() function:
if (TYPE == 1) {
serverMessages = new MyServerMessages(5002);
Toast.makeText(this,"Room Started Wait clients To Join",Toast.LENGTH_LONG).show();
}
else {
clientMessages = new MyClientMessages(deConvert(mycode)); // crash here
Toast.makeText(this,"Connect To Room",Toast.LENGTH_LONG).show();
}

why this client class crash and give me this error ?
Because you are creating a Socket and opening it in the constructor. Move that logic into run().

Sending a binary file over a Java Socket

I have written a multi-client TCP server that has the dual purpose of sending Json (text based) command strings and also sending an SQLite database file to multiple clients. Everything is working nicely except... the database file uses the special character hex81 (decimal 129) for some internal purpose. When I read the database file into a byte array, Java converts this character to decimal -127 because of Java's signed representation of bytes. However the socket is actually transmitting this character as hex3F. So when I receive the save the data in the client and save it to a file, the database is corrupt due to the presence of h3F chars instead of h81.
Why is this happening and how do I correct it?
Here is the complete code that I am using for the server (a new instance of this class is started by a separate TCPServer class whenever a client connects):
public class TCPServerThread extends Thread {
// Connect status constants
private final static int NULL = 0;
private final static int DISCONNECTED = 1;
private final static int DISCONNECTING = 2;
private final static int BEGIN_CONNECT = 3;
private final static int CONNECTED = 4;
private final static String END_SESSION = new Character((char)0).toString(); // Indicates the end of a session
// Connection state info
private int connectionStatus = DISCONNECTED;
private static StringBuffer txBuffer = new StringBuffer("");
private static ByteArrayOutputStream txBuffer2 = new ByteArrayOutputStream();
private static File file;
// TCP Components
private ServerSocket serverSocket = null;
private Socket clientSocket = null;
private BufferedReader in = null;
private PrintWriter out = null;
private DataOutputStream out2 = null;
private String s = "";
private DecodeJson dj = new DecodeJson();
private boolean doRun;
public TCPServerThread(Socket socket) throws IOException {
doRun = true;
clientSocket = socket;
changeStatusTS(BEGIN_CONNECT, true);
}
public void run() {
while (doRun) {
try { // run every ~10 ms
Thread.sleep(10);
}
catch (InterruptedException e) {}
if (Mainscreen.shutdown == true || TCPClient.close == true)
connectionStatus = DISCONNECTING;
switch (connectionStatus) {
case BEGIN_CONNECT:
try {
in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
out = new PrintWriter(clientSocket.getOutputStream(), true);
out2 = new DataOutputStream(clientSocket.getOutputStream());
TCPServer.writers.add(out); // add this socket to the connected clients list
changeStatusTS(CONNECTED, true);
}
// If error, clean up and output an error message
catch (IOException e) {
cleanUp();
changeStatusTS(DISCONNECTED, false);
}
break;
case CONNECTED:
try {
// Send data
if (txBuffer.length() != 0) {
for (PrintWriter writer : TCPServer.writers) {
writer.print(txBuffer);
writer.flush();
if(writer.checkError()) {
closeSocket();
changeStatusTS(DISCONNECTING, true);
}else {
changeStatusTS(NULL, true);
}
}
txBuffer.setLength(0);
}
if (txBuffer2.size() != 0) {
byte[] result = txBuffer2.toByteArray();
System.out.println(result[745] + "," + result[746] + "," + result[747] + "," + result[748] + "," + result[749] + "," + result[750]);
out2.write(result);
out2.flush();
txBuffer2.reset();
}
// Receive data
if (in.ready()) {
s = in.readLine();
if ((s != null) && (s.length() != 0)) {
// Check if it is the end of a transmission
if (s.equals(END_SESSION)) {
changeStatusTS(DISCONNECTING, true);
}
// Otherwise, receive text
else {
dj.receiveString(s);
changeStatusTS(NULL, true);
}
}
}
}
catch (IOException e) {
System.out.println("Socket error " + e);
cleanUp();
changeStatusTS(DISCONNECTED, false);
}
break;
case DISCONNECTING:
// Tell clients to disconnect as well
if (out != null) {
out.print(END_SESSION);
out.flush();
}
// Clean up (close all streams/sockets)
cleanUp();
changeStatusTS(DISCONNECTED, true);
break;
default: break;
}
}
}
// Add command to text send-buffer
public static void sendString(String s) {
synchronized (txBuffer) {
txBuffer.append(s + "\n");
}
}
// Add file data to binary send buffer
public static void sendFile(String filename) {
synchronized (txBuffer2) {
file = new File(filename);
byte[] content = new byte[(int)file.length()];
FileInputStream fin;
try {
fin = new FileInputStream(file);
fin.read(content);
System.out.println(content[745] + "," + content[746] + "," +content[747] + "," +content[748] + "," + content[749] + "," + content[750]);
txBuffer2.write(content);
fin.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException f) {
f.printStackTrace();
}
}
}
private void changeStatusTS(int newConnectStatus, boolean noError) {
// Change state if valid state
if (newConnectStatus != NULL) {
connectionStatus = newConnectStatus;
}
}
private void closeSocket(){
try {
if (clientSocket != null) {
clientSocket.close();
clientSocket = null;
}
}
catch (IOException e) { clientSocket = null; }
}
// Cleanup for disconnect
private void cleanUp() {
try {
if (serverSocket != null) {
serverSocket.close();
serverSocket = null;
}
}
catch (IOException e) { serverSocket = null; }
try {
if (clientSocket != null) {
clientSocket.close();
clientSocket = null;
}
}
catch (IOException e) { clientSocket = null; }
try {
if (in != null) {
in.close();
in = null;
}
}
catch (IOException e) { in = null; }
if (out != null) {
TCPServer.writers.remove(out); // remove this socket for the connected sockets list
out.close();
out = null;
}
doRun = false;
}
}

So as EJP suggested, the problem is due to using readers and writers.
The following code now works as expected (thanks for the tip EJP). I will get around to addressing the issue raised by VGR about wrapping client.getOutputStream() in both a PrintWriter and a BufferedOutputStream, but for now the code works nicely (this is a work in progress).
public class TCPServerThread extends Thread {
// Connect status constants
private final static int NULL = 0;
private final static int DISCONNECTED = 1;
private final static int DISCONNECTING = 2;
private final static int BEGIN_CONNECT = 3;
private final static int CONNECTED = 4;
private final static String END_SESSION = new Character((char)0).toString(); // Indicates the end of a session
// Connection state info
private int connectionStatus = DISCONNECTED;
private static StringBuffer txBuffer = new StringBuffer("");
private static BufferedOutputStream out2 = null;
private static File file;
// TCP Components
private ServerSocket serverSocket = null;
private Socket clientSocket = null;
private BufferedReader in = null;
private PrintWriter out = null;
private static BufferedInputStream fileData = null;
private String s = "";
private DecodeJson dj = new DecodeJson();
private boolean doRun;
public TCPServerThread(Socket socket) throws IOException {
doRun = true;
clientSocket = socket;
changeStatusTS(BEGIN_CONNECT, true);
}
public void run() {
while (doRun) {
try { // run every ~10 ms
Thread.sleep(10);
}
catch (InterruptedException e) {}
if (Mainscreen.shutdown == true || TCPClient.close == true)
connectionStatus = DISCONNECTING;
switch (connectionStatus) {
case BEGIN_CONNECT:
try {
in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
out = new PrintWriter(clientSocket.getOutputStream(), true);
out2 = new BufferedOutputStream(clientSocket.getOutputStream());
TCPServer.writers.add(out); // add this socket to the connected clients list
changeStatusTS(CONNECTED, true);
}
// If error, clean up and output an error message
catch (IOException e) {
cleanUp();
changeStatusTS(DISCONNECTED, false);
}
break;
case CONNECTED:
try {
// Send data
if (txBuffer.length() != 0) {
for (PrintWriter writer : TCPServer.writers) {
writer.print(txBuffer);
writer.flush();
if(writer.checkError()) {
closeSocket();
changeStatusTS(DISCONNECTING, true);
}else {
changeStatusTS(NULL, true);
}
}
txBuffer.setLength(0);
}
if (fileData != null) {
byte[] buffer = new byte[(int) file.length()];
for (int read = fileData.read(buffer); read >=0; read = fileData.read(buffer)) out2.write(buffer, 0, read);
out2.flush();
fileData = null;
}
// Receive data
if (in.ready()) {
s = in.readLine();
if ((s != null) && (s.length() != 0)) {
// Check if it is the end of a transmission
if (s.equals(END_SESSION)) {
changeStatusTS(DISCONNECTING, true);
}
// Otherwise, receive text
else {
dj.receiveString(s);
changeStatusTS(NULL, true);
}
}
}
}
catch (IOException e) {
System.out.println("Socket error " + e);
cleanUp();
changeStatusTS(DISCONNECTED, false);
}
break;
case DISCONNECTING:
// Tell clients to disconnect as well
if (out != null) {
out.print(END_SESSION);
out.flush();
}
// Clean up (close all streams/sockets)
cleanUp();
changeStatusTS(DISCONNECTED, true);
break;
default: break;
}
}
}
// Add command to text send-buffer
public static void sendString(String s) {
synchronized (txBuffer) {
txBuffer.append(s + "\n");
}
}
// Add file data to binary send buffer
public static void sendFile(String filename) {
file = new File(filename);
try {
fileData = new BufferedInputStream(new FileInputStream(file));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
private void changeStatusTS(int newConnectStatus, boolean noError) {
// Change state if valid state
if (newConnectStatus != NULL) {
connectionStatus = newConnectStatus;
}
}
private void closeSocket(){
try {
if (clientSocket != null) {
clientSocket.close();
clientSocket = null;
}
}
catch (IOException e) { clientSocket = null; }
}
// Cleanup for disconnect
private void cleanUp() {
try {
if (serverSocket != null) {
serverSocket.close();
serverSocket = null;
}
}
catch (IOException e) { serverSocket = null; }
try {
if (clientSocket != null) {
clientSocket.close();
clientSocket = null;
}
}
catch (IOException e) { clientSocket = null; }
try {
if (in != null) {
in.close();
in = null;
}
}
catch (IOException e) { in = null; }
if (out != null) {
TCPServer.writers.remove(out); // remove this socket for the connected sockets list
out.close();
out = null;
}
doRun = false;
}
}