Yet another chat program
hello all.
now i've read through alot of articles in the forum on this topic and i still can't figure it out. i have a multiple client server program and i can only send to all clients once they have sent something to the server first. any help is appreciated.
the code is here:
http://www.geocities.com/macca_thomo/program.zip
Please ignore the SPAM from richard west for his low grade wizard solutions forum. There are plenty of good examples on this forum, or do a search on the web.
When you say that your server won't reply until it the client sends something, do you mean that the server can send only one reply per input from the client? Is each client represented by a single thread which is waiting for input when you want it to send? Here's an example of a simple multithreaded chat server that I posted a few weeks ago on this forum: Simple Socket Server. It uses two threads per client to keep the communication going in both directions without needing to get complicated of do polling.
Similar Messages
-
Yet another chat applet, but with good reason...
Hi, I realise there are thousands of perfectly good chat applets out there (and millions of rubbish ones) but this is a last ditch to make something functional, fun and effective for my Computing Coursework. Thanks to AQA's sylabus, any remotely interesting topics are inplausable as it would result in me getting an instant U.
My questions on this topic are as follows...
What would be the best way to connect applets to server?
- Straightfoward Sockets
- RMI
- XML-RPC
With the last two would these run on joe user's browser without an additional extra bit being installed? Also, if sockets is the best answer is it possible to use XML as my data transfer medium? How can I encrypt this? If RMI is the best solution, are there any quick and concise tutorials kicking around? Will RMI be secure? How can I make it secure? Are all of the above clouding the issue too much and is there a better solution?
Thanks in advance. Sorry if that left your head in a spin...
- AndrewI did this a few years ago with straight socket communication. I would say start off with that, then if you'd like to use XML you can still send XML through the existing socket connections and parse it on the other end. But, there's no reason to make it more complicated than you need it, especially if you'll get a bad grade.
-
Yes, its another chat server/client program
Im busy writing a chat program and am having a problem figuring out how to show the users that are online. The ChatServer class contains methods for recieving messages, broadcasting messages, accepting new connections etc.
Im using non-blocking mode and I register all the connections with a Selector. When a new user connects to the server, I add the SocketChannel to a LinkedList which contains all the users that are online.
My problem is that my ChatServer class runs completly seperatly from any other classes (I presume thats normal?). In other words, I run the ChatServer and once that is running I run the StartGUI class which creates the swing gui and all of that. I then type in the host name etc and connect to the server. So how would I show the users that are online? Even if I can somehow get all the ip addresses then ill figure out how to give 'nicks' and all that from there.
As I said, I have a line (LinkedList.add(newChannel) which adds the clients to that list which I simply did so that i can display the number of users online. Is there a way I could now manipulate that LinkedList to get all the users and then display them (since it contains a list of all the SocketChannels)? Or would that not be possible?
If it is possible to get the users from the LinkedList, then the other problem is the fact that the list is created as part of the ChatServer so I cant get to it?
Another way that I thaught might be possible, is that since I register all the keys with a Selector when a new user is added (this happens in the ChatClient clas), then I might be able to get the users from that but im not sure if thats possible?
readSelector = Selector.open();
InetAddress addr = InetAddress.getByName(hostname);
channel = SocketChannel.open(new InetSocketAddress(addr, PORT));
channel.configureBlocking(false);
channel.register(readSelector, SelectionKey.OP_READ, new StringBuffer());Ill add to my explanation if need be, since im very new to this sort of programming. Ill post some more code if need be.
thanks, RThrough some more playing around this afternoon ive figured out how im going to solve my problem. It may not be the best way to do it but I think that at least it is going to work.
Im going to convert the LinkedList to a String and then change that into a ByteBuffer, and use channel.write(ByteBuffer) as if it was any other normal message.
My logic will be as follows:
Client: click 'get user list' button --> send String 'get users' to the server using channel.write("get users")
Server: read the String like any other normal String 'channel.read(ByteBuffer) --> decode the ByteBuffer back into a String --> if the String sais "get users" --> put the LinkedList into a String and then into a ByteBuffer --> send the buffer using channel.write(buffer)
Client: check the incoming buffer for some or other string (maybe an ip address) that will let it know that it is the list of users and not a normal string. Then use a bit of String manipulation to extract the IP addresses from the String.
Is this a reasonable way of doing it? Any other ideas?
Also,...Is it alright to add the linked list to a String and then into a ByteBuffer to send? Since if there are for example 100 users online then it will be quite a big string and therefore there will be a lot going into the buffer and being sent by the server. Are there any potential problems I could run into here with lots of users?
(lol, its been great talking to myself here ;) , hopefully some of you will have some comments or ideas after the weekend.)
R -
Multithreading issue with Client/Server chat program
In a nutshell, I just recently starting attempting to use Sockets and decided I wanted to give a go at a chat program. I have some experience with threads but I know little about how to find and fix multithreading issues. I think this is my problem right now since I am deadlocking while connecting and disconnecting client-side ... and updates about connection status of a client are not always displaying correctly server-side.
[ Code Snippet|http://snipplr.com/view/15206/clientserver-chat-program/]
Thanks for the helpNOTE: all catch clauses have been omitted for clarity. They all just perform System.err.println() with the msg embedded
Very valid point. I cut out the GUIs and just tried having the Server/Client communicate. I am still having concurrency issues. This is my first attempt at synchronized methods and locking objects so go easy on me if I did something(s) noob =D
public class MySocket
public static final String QUIT = "~~QUIT~~";
private ObjectOutputStream out;
private ObjectInputStream in;
private Socket conn;
public MySocket(String ip)
obsList = new ArrayList<IClientObs>();
try
conn = new Socket(ip, 5000);
if (conn.isConnected())
out = new ObjectOutputStream(conn.getOutputStream());
in = new ObjectInputStream(conn.getInputStream());
public synchronized String nextMsg()
String msg = "";
try
synchronized(in)
msg = (String)in.readObject();
notify(msg);
return(msg);
public synchronized boolean sendMsg(String msg)
boolean sentMsg = false;
try
synchronized(out)
if (out != null)
out.writeObject(msg);
out.flush();
sentMsg = true;
return(sentMsg);
public synchronized void closeConn()
try
synchronized(this)
sendMsg(QUIT);
conn.close();
out.close();
in.close();
public synchronized Socket getConn()
return(conn);
public synchronized ObjectOutputStream getOutStream()
return(out);
public synchronized ObjectInputStream getInStream()
return(in);
//Observer Pattern implemented below
public class Server extends Thread
public static final int MAX_CLIENTS = 2;
public static final String QUIT = "~~QUIT~~";
private ServerSocket server;
private ArrayList<ConnClient> conns;
private int connCount;
* Constructor for objects of class Server
public Server()
conns = new ArrayList<ConnClient>();
obsList = new ArrayList<IServerObs>();
connCount = 0;
public void startNow()
this.start();
public void run()
runServer();
public synchronized void runServer()
try
setup();
while (true)
waitForConn();
processComms();
private synchronized void setup() throws IOException
server = new ServerSocket(5000);
notify("Server initialized.\n");
private synchronized void waitForConn() throws IOException
if (connCount < MAX_CLIENTS)
notify("Waiting for connection...\n");
Socket conn = server.accept();
if (conn.isConnected())
conns.add(new ConnClient(conn));
notify("Client connected @ '" + conns.get(connCount).getIP() + "'.\n");
connCount++;
else
notify("Connection request rejected; max connections have been reached.\n");
private synchronized void processComms() throws IOException, ClassNotFoundException
//Receive any msgs sent by clients and forward msg to all clients
for(ConnClient rcvClient : conns)
String msg = rcvClient.nextMsg();
//if client quit, then close connection and remove it from list
if (msg.equals(QUIT))
notify("Client disconnected @ '" + rcvClient.getIP() + "'.\n");
rcvClient.closeConn();
conns.remove(rcvClient);
connCount--;
else
for(ConnClient sndClient : conns)
sndClient.sendMsg(msg);
public synchronized void shutdown()
try
server.close();
for(ConnClient client :conns)
client.closeConn();
//Observer Pattern implemented below
}I also found another issue that I haven't thought up a way to deal with yet. When the user starts the program the follow line is executed "conn = server.accept();" which halts execution
on that thread until a connection is established. What if the user wants to stop the server before a connection is made? The thread keeps running, waiting for a connection. How do I kill this thread?
On this last issue (I figured by adding the follow code to my action listener inside of my server gui I could stop the thread safely but it's no good so far)
public void actionPerformed(ActionEvent e)
Object src = e.getSource();
if (src == strBtn)
if (server == null)
strBtn.setEnabled(false);
stpBtn.setEnabled(true);
server = new Server();
server.addObserver(this);
server.start();
else
console.append("Console: Server is alread initiated.\n");
else if (src == stpBtn)
synchronized(server)
strBtn.setEnabled(true);
stpBtn.setEnabled(false);
server.shutdown();
server = null;
console.append("Console: Server has been stopped.\n");
}Edited by: mcox05 on May 21, 2009 10:05 AM
Edited by: mcox05 on May 21, 2009 10:17 AM
Edited by: mcox05 on May 21, 2009 10:58 AM
Edited by: mcox05 on May 21, 2009 11:01 AM
Edited by: mcox05 on May 21, 2009 11:03 AM
Edited by: mcox05 on May 21, 2009 11:03 AM -
After a few days work, I have completed the mian voice chat program. I know there are so many people like me that wants that. I post these program. i will complete gui work later. and there is a problem in the program. if the speaking one do not speak for a while, the listening client will hear noise. Can some one help me.
package com.longshine.voice;
import java.io.*;
import java.net.*;
import java.util.*;
public class Server
// The ServerSocket we'll use for accepting new connections
private ServerSocket ss;
// A mapping from sockets to DataOutputStreams. This will
// help us avoid having to create a DataOutputStream each time
// we want to write to a stream.
private Hashtable outputStreams = new Hashtable();
final int bufSize = 16384;
//current speak_man
private int speakman=-1;
// Constructor and while-accept loop all in one.
public Server( int port ) throws IOException {
// All we have to do is listen
listen( port );
private void listen( int port ) throws IOException {
// Create the ServerSocket
ss = new ServerSocket( port );
// Tell the world we're ready to go
System.out.println( "Listening on "+ss );
// Keep accepting connections forever
while (true) {
// Grab the next incoming connection
Socket s = ss.accept();
// Tell the world we've got it
System.out.println( "Connection from "+s );
// Create a DataOutputStream for writing data to the
// other side
DataOutputStream dout = new DataOutputStream( s.getOutputStream() );
// Save this stream so we don't need to make it again
outputStreams.put( s, dout );
// Create a new thread for this connection, and then forget
// about it
new VoiceServer( this, s );
// Get an enumeration of all the OutputStreams, one for each client
// connected to us
Enumeration getOutputStreams() {
return outputStreams.elements();
// Send a message to all clients (utility routine)
void sendToAll( byte[] voice ,Socket socket) {
// We synchronize on this because another thread might be
// calling removeConnection() and this would screw us up
// as we tried to walk through the list
synchronized( outputStreams ) {
// For each client ...
for (Enumeration e = outputStreams.keys(); e.hasMoreElements(); ) {
// ... get the output stream ...
Socket tmp=(Socket)e.nextElement();
if(!tmp.equals(socket))
try {
DataOutputStream dout = new DataOutputStream(tmp.getOutputStream());
// ... and send the message
dout.write(voice,0,44096);
dout.flush();
} catch( IOException ie ) { System.out.println( ie ); }
// Remove a socket, and it's corresponding output stream, from our
// list. This is usually called by a connection thread that has
// discovered that the connectin to the client is dead.
void removeConnection( Socket s ) {
// Synchronize so we don't mess up sendToAll() while it walks
// down the list of all output streamsa
synchronized( outputStreams ) {
// Tell the world
System.out.println( "Removing connection to "+s );
// Remove it from our hashtable/list
outputStreams.remove( s );
// Make sure it's closed
try {
s.close();
} catch( IOException ie ) {
System.out.println( "Error closing "+s );
ie.printStackTrace();
// Main routine
// Usage: java Server <port>
static public void main( String args[] ) throws Exception {
// Get the port # from the command line
int port = Integer.parseInt( args[0] );
// Create a Server object, which will automatically begin
// accepting connections.
new Server( port );
package com.longshine.voice;
import java.net.*;
import java.io.*;
import java.sql.*;
import java.io.*;
import java.net.*;
public class VoiceServer extends Thread
// The Server that spawned us
private Server server;
final int bufSize = 16384;
// The Socket connected to our client
private Socket socket;
// Constructor.
public VoiceServer( Server server, Socket socket ) {
// Save the parameters
this.server = server;
this.socket = socket;
// Start up the thread
start();
// This runs in a separate thread when start() is called in the
// constructor.
public void run() {
try {
// Create a DataInputStream for communication; the client
// is using a DataOutputStream to write to us
DataInputStream din = new DataInputStream( socket.getInputStream() );
byte[] voice=new byte[44096];
// Over and over, forever ...
while (true) {
// ... read the next message ...
// int bytes = din.read(voice,0,44096);
int bytes = din.read(voice);
// ... and have the server send it to all clients
server.sendToAll(voice,socket);
} catch( EOFException ie ) {
// This doesn't need an error message
} catch( IOException ie ) {
// This does; tell the world!
ie.printStackTrace();
} finally {
// The connection is closed for one reason or another,
// so have the server dealing with it
server.removeConnection( socket );
package com.longshine.voice;
import java.io.*;
import java.net.*;
public class Client {
private String host="";
private String port="";
private Socket socket;
private DataOutputStream dout;
private DataInputStream din;
private Capture capture=null;
private Play play=null;
public Client(String host,String port) {
this.host=host;
this.port=port;
public void init()
try
socket = new Socket( host, Integer.parseInt(port));
din = new DataInputStream( socket.getInputStream() );
dout = new DataOutputStream( socket.getOutputStream());
capture=new Capture(dout);
play=new Play(din);
catch(Exception e)
e.printStackTrace();
public static void main(String[] args) {
Client client = new Client("172.18.220.176","5678");
client.init();
if(args[0].equalsIgnoreCase("say"))
client.capture.start();
if(args[0].equalsIgnoreCase("hear"))
client.play.start();
package com.longshine.voice;
import java.io.*;
import java.util.Vector;
import java.util.Enumeration;
import javax.sound.sampled.*;
import java.text.*;
import java.net.*;
public class Play implements Runnable {
SourceDataLine line;
Thread thread;
String errStr=null;
DataInputStream in=null;
AudioInputStream audioInputStream;
final int bufSize = 16384;
int duration=0;
public Play(DataInputStream in)
this.in=in;
public void start() {
errStr = null;
thread = new Thread(this);
thread.setName("Playback");
thread.start();
public void stop() {
thread = null;
private void shutDown(String message) {
if ((errStr = message) != null) {
System.err.println(errStr);
if (thread != null) {
thread = null;
public void createAudioInputStream() {
if (in != null ) {
try {
errStr = null;
java.io.BufferedInputStream oin = new java.io.BufferedInputStream(in);
audioInputStream = AudioSystem.getAudioInputStream(oin);
} catch (Exception ex) {
ex.printStackTrace();
} else {
public void run() {
// reload the file if loaded by file
if (in != null) {
// createAudioInputStream();
// make sure we have something to play
// if (audioInputStream == null) {
// shutDown("No loaded audio to play back");
// return;
// reset to the beginnning of the stream
// try {
// audioInputStream.reset();
// } catch (Exception e) {
// shutDown("Unable to reset the stream\n" + e);
// return;
// get an AudioInputStream of the desired format for playback
AudioFormat format = getFormat();
audioInputStream=new AudioInputStream(in, format, AudioSystem.NOT_SPECIFIED);
AudioInputStream playbackInputStream = AudioSystem.getAudioInputStream(format, audioInputStream);
if (playbackInputStream == null) {
shutDown("Unable to convert stream of format " + audioInputStream + " to format " + format);
return;
// define the required attributes for our line,
// and make sure a compatible line is supported.
DataLine.Info info = new DataLine.Info(SourceDataLine.class,
format);
if (!AudioSystem.isLineSupported(info)) {
shutDown("Line matching " + info + " not supported.");
return;
// get and open the source data line for playback.
try {
line = (SourceDataLine) AudioSystem.getLine(info);
line.open(format, bufSize);
} catch (LineUnavailableException ex) {
shutDown("Unable to open the line: " + ex);
return;
// play back the captured audio data
int frameSizeInBytes = format.getFrameSize();
int bufferLengthInFrames = line.getBufferSize() / 8;
int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes;
byte[] data = new byte[bufferLengthInBytes];
int numBytesRead = 0;
// start the source data line
line.start();
while (thread != null) {
try {
if ((numBytesRead = playbackInputStream.read(data)) == -1) {
break;
int numBytesRemaining = numBytesRead;
while (numBytesRemaining > 0 ) {
numBytesRemaining -= line.write(data, 0, numBytesRemaining);
} catch (Exception e) {
shutDown("Error during playback: " + e);
break;
// we reached the end of the stream. let the data play out, then
// stop and close the line.
if (thread != null) {
line.drain();
line.stop();
line.close();
line = null;
shutDown(null);
public AudioFormat getFormat() {
AudioFormat.Encoding encoding = AudioFormat.Encoding.ULAW;
String encString = "linear";
float rate = Float.valueOf("44100").floatValue();
int sampleSize = 16;
String signedString = "signed";
boolean bigEndian = true;
int channels = 2;
if (encString.equals("linear")) {
if (signedString.equals("signed")) {
encoding = AudioFormat.Encoding.PCM_SIGNED;
} else {
encoding = AudioFormat.Encoding.PCM_UNSIGNED;
} else if (encString.equals("alaw")) {
encoding = AudioFormat.Encoding.ALAW;
return new AudioFormat(encoding, rate, sampleSize,
channels, (sampleSize/8)*channels, rate, bigEndian);
} // End class Playback
package com.longshine.voice;
import java.io.*;
import java.util.Vector;
import java.util.Enumeration;
import javax.sound.sampled.*;
import java.text.*;
import java.net.*;
public class Capture implements Runnable {
TargetDataLine line;
Thread thread;
String errStr=null;
DataOutputStream out=null;
AudioInputStream audioInputStream;
final int bufSize = 16384;
int duration=0;
public Capture(DataOutputStream out)
this.out=out;
public void start() {
errStr = null;
thread = new Thread(this);
thread.setName("Playback");
thread.start();
public void stop() {
thread = null;
private void shutDown(String message) {
if ((errStr = message) != null) {
System.out.println(errStr);
if (thread != null) {
thread = null;
public AudioFormat getFormat() {
AudioFormat.Encoding encoding = AudioFormat.Encoding.ULAW;
String encString = "linear";
float rate = Float.valueOf("44100").floatValue();
int sampleSize = 16;
String signedString = "signed";
boolean bigEndian = true;
int channels = 2;
if (encString.equals("linear")) {
if (signedString.equals("signed")) {
encoding = AudioFormat.Encoding.PCM_SIGNED;
} else {
encoding = AudioFormat.Encoding.PCM_UNSIGNED;
} else if (encString.equals("alaw")) {
encoding = AudioFormat.Encoding.ALAW;
return new AudioFormat(encoding, rate, sampleSize,
channels, (sampleSize/8)*channels, rate, bigEndian);
public void run() {
duration = 0;
audioInputStream = null;
// define the required attributes for our line,
// and make sure a compatible line is supported.
AudioFormat format = getFormat();
DataLine.Info info = new DataLine.Info(TargetDataLine.class,
format);
if (!AudioSystem.isLineSupported(info)) {
shutDown("Line matching " + info + " not supported.");
return;
// get and open the target data line for capture.
try {
line = (TargetDataLine) AudioSystem.getLine(info);
line.open(format, line.getBufferSize());
} catch (LineUnavailableException ex) {
shutDown("Unable to open the line: " + ex);
return;
} catch (SecurityException ex) {
shutDown(ex.toString());
return;
} catch (Exception ex) {
shutDown(ex.toString());
return;
// play back the captured audio data
int frameSizeInBytes = format.getFrameSize();
int bufferLengthInFrames = line.getBufferSize() / 8;
int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes;
byte[] data = new byte[bufferLengthInBytes];
int numBytesRead;
line.start();
try
while (thread != null) {
if((numBytesRead = line.read(data, 0, bufferLengthInBytes)) == -1) {
break;
if(data.length>0)
out.write(data, 0, numBytesRead);
out.flush();
catch (Exception e)
e.printStackTrace();
// we reached the end of the stream. stop and close the line.
line.stop();
line.close();
line = null;
// stop and close the output stream
try {
out.flush();
out.close();
} catch (IOException ex) {
ex.printStackTrace();
} // End class CaptureAfter a few days work, I have completed the mian voice chat program. I know there are so many people like me that wants that. I post these program. i will complete gui work later. and there is a problem in the program. if the speaking one do not speak for a while, the listening client will hear noise. Can some one help me.
package com.longshine.voice;
import java.io.*;
import java.net.*;
import java.util.*;
public class Server
// The ServerSocket we'll use for accepting new connections
private ServerSocket ss;
// A mapping from sockets to DataOutputStreams. This will
// help us avoid having to create a DataOutputStream each time
// we want to write to a stream.
private Hashtable outputStreams = new Hashtable();
final int bufSize = 16384;
//current speak_man
private int speakman=-1;
// Constructor and while-accept loop all in one.
public Server( int port ) throws IOException {
// All we have to do is listen
listen( port );
private void listen( int port ) throws IOException {
// Create the ServerSocket
ss = new ServerSocket( port );
// Tell the world we're ready to go
System.out.println( "Listening on "+ss );
// Keep accepting connections forever
while (true) {
// Grab the next incoming connection
Socket s = ss.accept();
// Tell the world we've got it
System.out.println( "Connection from "+s );
// Create a DataOutputStream for writing data to the
// other side
DataOutputStream dout = new DataOutputStream( s.getOutputStream() );
// Save this stream so we don't need to make it again
outputStreams.put( s, dout );
// Create a new thread for this connection, and then forget
// about it
new VoiceServer( this, s );
// Get an enumeration of all the OutputStreams, one for each client
// connected to us
Enumeration getOutputStreams() {
return outputStreams.elements();
// Send a message to all clients (utility routine)
void sendToAll( byte[] voice ,Socket socket) {
// We synchronize on this because another thread might be
// calling removeConnection() and this would screw us up
// as we tried to walk through the list
synchronized( outputStreams ) {
// For each client ...
for (Enumeration e = outputStreams.keys(); e.hasMoreElements(); ) {
// ... get the output stream ...
Socket tmp=(Socket)e.nextElement();
if(!tmp.equals(socket))
try {
DataOutputStream dout = new DataOutputStream(tmp.getOutputStream());
// ... and send the message
dout.write(voice,0,44096);
dout.flush();
} catch( IOException ie ) { System.out.println( ie ); }
// Remove a socket, and it's corresponding output stream, from our
// list. This is usually called by a connection thread that has
// discovered that the connectin to the client is dead.
void removeConnection( Socket s ) {
// Synchronize so we don't mess up sendToAll() while it walks
// down the list of all output streamsa
synchronized( outputStreams ) {
// Tell the world
System.out.println( "Removing connection to "+s );
// Remove it from our hashtable/list
outputStreams.remove( s );
// Make sure it's closed
try {
s.close();
} catch( IOException ie ) {
System.out.println( "Error closing "+s );
ie.printStackTrace();
// Main routine
// Usage: java Server <port>
static public void main( String args[] ) throws Exception {
// Get the port # from the command line
int port = Integer.parseInt( args[0] );
// Create a Server object, which will automatically begin
// accepting connections.
new Server( port );
package com.longshine.voice;
import java.net.*;
import java.io.*;
import java.sql.*;
import java.io.*;
import java.net.*;
public class VoiceServer extends Thread
// The Server that spawned us
private Server server;
final int bufSize = 16384;
// The Socket connected to our client
private Socket socket;
// Constructor.
public VoiceServer( Server server, Socket socket ) {
// Save the parameters
this.server = server;
this.socket = socket;
// Start up the thread
start();
// This runs in a separate thread when start() is called in the
// constructor.
public void run() {
try {
// Create a DataInputStream for communication; the client
// is using a DataOutputStream to write to us
DataInputStream din = new DataInputStream( socket.getInputStream() );
byte[] voice=new byte[44096];
// Over and over, forever ...
while (true) {
// ... read the next message ...
// int bytes = din.read(voice,0,44096);
int bytes = din.read(voice);
// ... and have the server send it to all clients
server.sendToAll(voice,socket);
} catch( EOFException ie ) {
// This doesn't need an error message
} catch( IOException ie ) {
// This does; tell the world!
ie.printStackTrace();
} finally {
// The connection is closed for one reason or another,
// so have the server dealing with it
server.removeConnection( socket );
package com.longshine.voice;
import java.io.*;
import java.net.*;
public class Client {
private String host="";
private String port="";
private Socket socket;
private DataOutputStream dout;
private DataInputStream din;
private Capture capture=null;
private Play play=null;
public Client(String host,String port) {
this.host=host;
this.port=port;
public void init()
try
socket = new Socket( host, Integer.parseInt(port));
din = new DataInputStream( socket.getInputStream() );
dout = new DataOutputStream( socket.getOutputStream());
capture=new Capture(dout);
play=new Play(din);
catch(Exception e)
e.printStackTrace();
public static void main(String[] args) {
Client client = new Client("172.18.220.176","5678");
client.init();
if(args[0].equalsIgnoreCase("say"))
client.capture.start();
if(args[0].equalsIgnoreCase("hear"))
client.play.start();
package com.longshine.voice;
import java.io.*;
import java.util.Vector;
import java.util.Enumeration;
import javax.sound.sampled.*;
import java.text.*;
import java.net.*;
public class Play implements Runnable {
SourceDataLine line;
Thread thread;
String errStr=null;
DataInputStream in=null;
AudioInputStream audioInputStream;
final int bufSize = 16384;
int duration=0;
public Play(DataInputStream in)
this.in=in;
public void start() {
errStr = null;
thread = new Thread(this);
thread.setName("Playback");
thread.start();
public void stop() {
thread = null;
private void shutDown(String message) {
if ((errStr = message) != null) {
System.err.println(errStr);
if (thread != null) {
thread = null;
public void createAudioInputStream() {
if (in != null ) {
try {
errStr = null;
java.io.BufferedInputStream oin = new java.io.BufferedInputStream(in);
audioInputStream = AudioSystem.getAudioInputStream(oin);
} catch (Exception ex) {
ex.printStackTrace();
} else {
public void run() {
// reload the file if loaded by file
if (in != null) {
// createAudioInputStream();
// make sure we have something to play
// if (audioInputStream == null) {
// shutDown("No loaded audio to play back");
// return;
// reset to the beginnning of the stream
// try {
// audioInputStream.reset();
// } catch (Exception e) {
// shutDown("Unable to reset the stream\n" + e);
// return;
// get an AudioInputStream of the desired format for playback
AudioFormat format = getFormat();
audioInputStream=new AudioInputStream(in, format, AudioSystem.NOT_SPECIFIED);
AudioInputStream playbackInputStream = AudioSystem.getAudioInputStream(format, audioInputStream);
if (playbackInputStream == null) {
shutDown("Unable to convert stream of format " + audioInputStream + " to format " + format);
return;
// define the required attributes for our line,
// and make sure a compatible line is supported.
DataLine.Info info = new DataLine.Info(SourceDataLine.class,
format);
if (!AudioSystem.isLineSupported(info)) {
shutDown("Line matching " + info + " not supported.");
return;
// get and open the source data line for playback.
try {
line = (SourceDataLine) AudioSystem.getLine(info);
line.open(format, bufSize);
} catch (LineUnavailableException ex) {
shutDown("Unable to open the line: " + ex);
return;
// play back the captured audio data
int frameSizeInBytes = format.getFrameSize();
int bufferLengthInFrames = line.getBufferSize() / 8;
int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes;
byte[] data = new byte[bufferLengthInBytes];
int numBytesRead = 0;
// start the source data line
line.start();
while (thread != null) {
try {
if ((numBytesRead = playbackInputStream.read(data)) == -1) {
break;
int numBytesRemaining = numBytesRead;
while (numBytesRemaining > 0 ) {
numBytesRemaining -= line.write(data, 0, numBytesRemaining);
} catch (Exception e) {
shutDown("Error during playback: " + e);
break;
// we reached the end of the stream. let the data play out, then
// stop and close the line.
if (thread != null) {
line.drain();
line.stop();
line.close();
line = null;
shutDown(null);
public AudioFormat getFormat() {
AudioFormat.Encoding encoding = AudioFormat.Encoding.ULAW;
String encString = "linear";
float rate = Float.valueOf("44100").floatValue();
int sampleSize = 16;
String signedString = "signed";
boolean bigEndian = true;
int channels = 2;
if (encString.equals("linear")) {
if (signedString.equals("signed")) {
encoding = AudioFormat.Encoding.PCM_SIGNED;
} else {
encoding = AudioFormat.Encoding.PCM_UNSIGNED;
} else if (encString.equals("alaw")) {
encoding = AudioFormat.Encoding.ALAW;
return new AudioFormat(encoding, rate, sampleSize,
channels, (sampleSize/8)*channels, rate, bigEndian);
} // End class Playback
package com.longshine.voice;
import java.io.*;
import java.util.Vector;
import java.util.Enumeration;
import javax.sound.sampled.*;
import java.text.*;
import java.net.*;
public class Capture implements Runnable {
TargetDataLine line;
Thread thread;
String errStr=null;
DataOutputStream out=null;
AudioInputStream audioInputStream;
final int bufSize = 16384;
int duration=0;
public Capture(DataOutputStream out)
this.out=out;
public void start() {
errStr = null;
thread = new Thread(this);
thread.setName("Playback");
thread.start();
public void stop() {
thread = null;
private void shutDown(String message) {
if ((errStr = message) != null) {
System.out.println(errStr);
if (thread != null) {
thread = null;
public AudioFormat getFormat() {
AudioFormat.Encoding encoding = AudioFormat.Encoding.ULAW;
String encString = "linear";
float rate = Float.valueOf("44100").floatValue();
int sampleSize = 16;
String signedString = "signed";
boolean bigEndian = true;
int channels = 2;
if (encString.equals("linear")) {
if (signedString.equals("signed")) {
encoding = AudioFormat.Encoding.PCM_SIGNED;
} else {
encoding = AudioFormat.Encoding.PCM_UNSIGNED;
} else if (encString.equals("alaw")) {
encoding = AudioFormat.Encoding.ALAW;
return new AudioFormat(encoding, rate, sampleSize,
channels, (sampleSize/8)*channels, rate, bigEndian);
public void run() {
duration = 0;
audioInputStream = null;
// define the required attributes for our line,
// and make sure a compatible line is supported.
AudioFormat format = getFormat();
DataLine.Info info = new DataLine.Info(TargetDataLine.class,
format);
if (!AudioSystem.isLineSupported(info)) {
shutDown("Line matching " + info + " not supported.");
return;
// get and open the target data line for capture.
try {
line = (TargetDataLine) AudioSystem.getLine(info);
line.open(format, line.getBufferSize());
} catch (LineUnavailableException ex) {
shutDown("Unable to open the line: " + ex);
return;
} catch (SecurityException ex) {
shutDown(ex.toString());
return;
} catch (Exception ex) {
shutDown(ex.toString());
return;
// play back the captured audio data
int frameSizeInBytes = format.getFrameSize();
int bufferLengthInFrames = line.getBufferSize() / 8;
int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes;
byte[] data = new byte[bufferLengthInBytes];
int numBytesRead;
line.start();
try
while (thread != null) {
if((numBytesRead = line.read(data, 0, bufferLengthInBytes)) == -1) {
break;
if(data.length>0)
out.write(data, 0, numBytesRead);
out.flush();
catch (Exception e)
e.printStackTrace();
// we reached the end of the stream. stop and close the line.
line.stop();
line.close();
line = null;
// stop and close the output stream
try {
out.flush();
out.close();
} catch (IOException ex) {
ex.printStackTrace();
} // End class Capture -
Is this yet another problem with 7.5 or is it just me . . .
Upgrade seemed to be fine, at first . . . now I keep getting distortion on songs. It seems to be quite random and just because a song has been distorted when I've listened to it once doesn't mean it will be when I listen to it again! It's driving me insane. Is this yet another bug or have I done something wrong (apart from upgrading to 7.5).
Hi Emlou,
If you have a Windows based operating system such as XP -
It seems to me that you are suffering what I am having the same problem with - the program takes up to much of your computer's processing usage. If you go into your task manager and watch performance as ITunes runs - you will see how much of the total computer usage it is taking at any given moment - that's why your songs are distorted, slowing, garbled, etc - the usage on mine spikes from 11% - 93% AT ANY GIVEN MINUTE! I have no idea why, but I have found that by going to your "Control Panel" and clicking on Quicktime you can adjust audio output to help. Click the audio tab, click Safe Mode Wavout only (checkbox) / Then adjust the "Rate" to 96kHz / Then adjust the "Size" to 16 bit. Close that and shut down and restart Itunes - it might help a little for you.
Maybe someone out there can help us find out why we are suffering with all the CPU usage trouble and how to adjust that spiking.
Thanks!
Paul -
Yet another grey folder thread, help!
Sorry for yet another grey folder thread, but here goes:
Today, earlier, installed Firefox update, along with some addon updates for that program. Quit Firefox and attempt to relaunch, relaunch fails. Reset computer, thinking that will do the trick, I now have grey folder with question mark.
Resolve attempts: reset pram = fail; apple care cd = will not launch/fail; disk utility from original install disks = fail; cannot get repair of disk or permissions to work, continually get error about "failing on exit"; safe mode launch = fail
So, I've done everything, and I've come to conclusion that I am f***, and my HDD is fried (but I hope I am wrong).
So, dear gurus, my question(s)
A) Is my HDD salvageable at all? is there some trick to getting the AppleCare cd to work? Anything?!?!
if not, then B) How can I recover my documents/music/pictures? Long story short, there are several things on there that never had a chance to make my back up schedule, and I desperately want to keep them. Any way to make/copy a disk image to save the docs/imgs, or Firewire them to an external hdd? Do I need to consider a professional HDD rescue?Looks like a mechanical failure, and Apple won't cover the replacement due to a drop it sustained a year or two ago (the power cable was in, and it fell on the connection point, denting that in, Apple states there is a critical board their and that it would be $950 Tier 3 repair which I can't afford). So I'm going to try a Firewire Migration and a few other things and see if that works. If not, oh well. Thanks everyone for the ideas!
-
Yet another "fail to respond".....
I've had a look around on the posts and can't find a problem that quite matches this. I bought my parents a G5 iMac with an external iSight just over a year ago. We've been using iChat happily since then, til today.
Originally I had G4 iMac with iSight on panther. Since then we've both upgraded to Tiger, and I've upgraded to a G5 iMac 2.1 with built in iSight. Still no problems. Just after christmas I invested in a Zoom ethernet modem and tonight was the first time since then we've tried to iChat. Depending on who's trying to accept the chat, they recieve the message that they have failed to respond.
Both firewalls are off and encryption is not enabled. This would suggest to me that it might be my new modem. So I powered up my old G4 connected with my old modem, but still no audio or videochats, with the same error messages.
I don't see why I should be getting the same problem with my old set up too when it worked fine before (G4 running Tiger too).
Any thoughts?HI Veeto,
Ok your parents may have set up Port Forwarding like this (I can not UPnP listed on this screen shots).
UPnP stands for Universal Pug n Play.
It is one means of making sure the Ports in a cable or ADSL modem are open.
Port Forwarding is another and Port Tiggering is yet another.
Sometimes a cabele modem can be set as a Straight through device much like a USB modem.
An ADSL modem is likely to come with some ports pen by default which allow you to Plug and Play with your Web broswer and Mail applications and Send and get files over FTP.
However iChat uses ports ports above the 1024 threshold for these open ports. This means you have to open the ports.
If you have the Access IP and Default Password and User ID for your 5660ADSL modem then you will be able to do the same.
The page I linked you to has all the ports you need for AIM and Jabber accounts to work.
This is on of the other Zoom's Pages for the same thing. Similar but different.
You should be able to work out how to set yours up.
Ideally you need to use UPnP or Port Triggering to use two computers at one location with iChat as these both allow multiple computer to use the same ports (Port Forwarding does not).
It might be you have newer firmware on your modem than is shown in these pics and you might have UPnP.
http://www.zoom.com/techsupport/adsl/adsl_x3.shtml (Firmware page).
I do not see that it says it has UPnP on thier site.
Ralph -
hey guys, im new to the whole networking thing, and this is my first attempt at using the internet. i am making a chat program, and having some troubles.
import java.net.*;
import javax.swing.*;
import java.io.*;
import java.awt.event.*;
import java.awt.*;
import java.util.*;
public class CHAT2 extends JFrame implements Runnable, ActionListener
Thread Client = new Thread(this, "Client");
DatagramSocket ds;
public int buffer_size = 1024;
public byte buffer[] = new byte[buffer_size];
public final int PORT = 3677;
JTextField jt;
JTextArea jto;
public CHAT2() {
Thread.currentThread().setName("Server");
setDefaultCloseOperation(EXIT_ON_CLOSE);
try {
ds = new DatagramSocket(PORT);
}catch(SocketException ec) {
JPanel jp = new JPanel();
jp.setLayout(new GridLayout(2,2));
setTitle("MChat");
setSize(400,400);
setResizable(false);
jt = new JTextField();
jto = new JTextArea();
jto.setFont(new Font("Arial", Font.BOLD, 12));
jto.setForeground(Color.BLUE);
jto.setEditable(false);
//jt.setSize(100,20);
//jt.setLocation(10,50);
JButton b = new JButton("Send Message");
//b.setSize(100,40);
//b.setLocation(10,100);
getContentPane().setLayout(new BorderLayout());
//getContentPane().add(b);
jp.add(jt);
jp.add(b);
getContentPane().add(jto, BorderLayout.CENTER);
getContentPane().add(jp, BorderLayout.SOUTH);
b.addActionListener(this);
Client.start();
public void run() {
try {
for(;;) {
buffer = new byte[buffer_size];
DatagramPacket p = new DatagramPacket(buffer, buffer.length);
try {
ds.receive(p);
}catch(IOException ec) {
String temp = new String(p.getData(), 0, p.getLength());
System.out.println(temp);
if(jto.getText().length() > 1) jto.setText(jto.getText() + "\n" + temp);
else jto.setText(temp);
Thread.sleep(1);
}catch(InterruptedException ec) {
public void actionPerformed(ActionEvent ae)
send(jt.getText());
public void send(String e)
int c = 0;
while(c < e.length()) {
buffer[c] = (byte) (e.charAt(c) );
c++;
try {
ds.send(new DatagramPacket(buffer,c, InetAddress.getLocalHost(), PORT));
}catch(IOException ec) {
public static void main(String args[])
System.out.println(new Date().getDay());
CHAT2 ch = new CHAT2();
ch.setVisible(true);
}it works when i use it on my computer, but when trying to go across my network it does not. i have a feeling it traces back to this line
ds.send(new DatagramPacket(buffer,c, InetAddress.getLocalHost(), PORT));
any ideas on how to fix it?
(remember i am very new to networking, so dont expect me to know much....)InetAddress.getLocalHost() gets your localhost ip. i.e. the ip of the computer you are running the program on which means you will send the package to the same computer. to send it to another computer enter the ip-address of it.
-
Help needed with a chat program
Hi everyone! i'm busy with a client/server chat program. I'm really stuck because i can't seem to get the messages from one client to show on the other client's screen.
If one client sends a message to another client, the server receives the message, but the second client does not receive the message.
Here is the server code that sends messages to the clients:
BufferedReader incomeReader = null;
PrintWriter outWriter = null;
try {
incomeReader = new BufferedReader(new InputStreamReader (incomingSocket.getInputStream()));
outWriter = new PrintWriter(incomingSocket.getOutputStream(),true);
}catch (Exception e) {
System.out.println("error handling a client: " + e);
System.exit(-1);
line = incomeReader.readLine();
textArea.append(line + "\n");
outWriter.println(line);
The server is suppose to put the message it receives on the text area on the server screen, and then send the message to all clients connected to it.
I hope somebody will be able to help me...The code posted just sends any data it receives back to the person who sent it. To get it to work there, you probably should flush after the println. I believe your mother taught you always to flush. It seems you have forgotten.
-
Adding nicknames to chat program
Hi there,
I'm developing a chat program in java for school.
I already have the basics. I have a client, a server, and so on...
The communication had already been set right.
But now I want to let the client (user, who wants to chat) choose their nickname.
There cannot be 2 persons with the same nickname.
So I probably have to save those nicknames at the server.
How is the best way to approach this?
Just sending a nickname as a string is probably not a good way. Because the server had to make a difference between text (that has to be sent to every client) and other data (like a nickname).
I have no idea how to do this. How is this handled by other chat programs?
I hope someone can point me some ways to solve this.
Thanks in advance!I see that you have every string that comes in as a message from that client.
What you should do is have the client type in his name before.
The string contains a special code to tell the server that it is a name. Such as: "<incomingnickname>ejito</incomingnickname>". When the server gets this information it will parse the nickname and send that name to respective database of current clients connected. It will then allow that person to speak and show up in the room.
The server checks whether names are already in use by looking through the database of clients.
If that name is currently taken, then the sever will send back a "<nicknamefailed> That nick is taken! Choose another</nicknamefailed>", and not allow the user to talk in the room until he gets a new name. The server will just trash all incoming messages from that client.
This is pretty secure. Since the server does the checking, and also prevents the user from speaking or appearing in the chat, it will prevent people from trying to duplicate the person's name. -
After having yet another problem with my MacBook Pro and having to wipe the drive, I am now unable to sync my iPhones etc without erasing all the music on them. Is there a way around this? I have no other library!
iTunes is a mess! It couldn't find it's own libraries and I was forced to create a new one. Now I don't know where my music is or if any's missing.columbus new boy wrote:
How crap is that?
It's not crap at all.
It's not that simple. For example, I've 3500 songs on my MacBook but don't want them all on my phone, so I have to manually select each song again???
There has to be a solution.
Why not simply make a playlist with the songs you want on the iPhone?
and maintain a current backup of your computer. -
How to call a dialog program with return value in another dialog program
Dear All,
How can I call a dialog program with return value from another dialog program?
Regards,
Alok.Hi Alok,
You can you SET/GET parameters to do this.
This is some information about this.
To fill the input fields of a called transaction with data from the calling program, you can use the SPA/GPA technique. SPA/GPA parameters are values that the system stores in the global, user-specific SAP memory. SAP memory allows you to pass values between programs. A user can access the values stored in the SAP memory during one terminal session for all parallel sessions. Each SPA/GPA parameter is identified by a 20-character code. You can maintain them in the Repository Browser in the ABAP Workbench. The values in SPA/GPA parameters are user-specific.
ABAP programs can access the parameters using the SET PARAMETER and GET PARAMETERstatements.
To fill one, use:
SET PARAMETER ID pid FIELD f.
This statement saves the contents of field f under the ID pid in the SAP memory. The ID pid can be up to 20 characters long. If there was already a value stored under pid, this statement overwrites it. If you double-click pid in the ABAP Editor, parameters that do not exist can be created as a Repository object.
To read an SPA/GPA parameter, use:
GET PARAMETER ID pid FIELD f.
This statement places the value stored under the pid ID into the variable f. If the system does not find any value for pid in the SAP memory, sy-subrc is set to 4. Otherwise, it sets the value to 0.
Thanks,
SriRatna -
How to call a Dialog Program from another Dialog Program
Dear All,
How can I call a dialog program with return value from another dialog program?
Regards,
Alok.Hi Alok,
1. Insted of creating 2 different Dialog program. It's good to create as many screens as you want in same module pool program. Any way you can use the different TCODE for each screen.
2. Another and The best way is to create a function group and then inside function group use the function 2 module... In the function group define a global variable which will be present for both the function group if they are getting executed in sequence. and inside the Function Module call the screens using command " call screen <screenno>".
3. You can use set / get parameter to pass values of a field between two dynpro program. -
How to Spawn a concurrent program from another Concurrent Program
Hi,
I need to write a concurrent program with PL/sql procedure. Inside this procedure, for a cursor data, for each record I need to spawn another concurrent program. How can I do this. Should I call a concurrent program using fnd_request.submit_request?
Any suggestions?
Thanks,
HCCorrect - you will need to use FND_REQUEST. Pl use the search feature of these forums to find old threads that discuss this topic
https://forums.oracle.com/forums/search.jspa?threadID=&q=FND_REQUEST+AND+SUBMIT_REQUEST&objID=c3&dateRange=all&userID=&numResults=15
How To Submit A Concurrent Request Set Using Fnd_Request.Submit_Request [Document 382791.1]
Most Commonly Used FND APIs in APPS Customizations [Document 221549.1]
HTH
Srini
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