Using Sockets with BufferedInputStream
Hi,
Many thanks in advance for any help or advice. I have been struggling with this for a while now.
I have data comming in from a Socket. I create a BufferedInputStream like this:
inputStream = new BufferedInputStream( socket.getInputStream() ); The class that this code is in extends Thread, and in the run method i have:
while( true )
try
inputSource = new InputSource( inputStream );
responseXML.parseClientData( inputSource, client.getID() );
catch( Exception e )
System.out.println( "run.Error: " + e );
}The class responseXML takes the stream and tries to parse the XML as follows:
public void parseClientData( InputSource dataFromFlash, int clientID )
System.out.println( "parseClientData" + clientID );
try
xmlReader.parse( dataFromFlash );
catch( Exception e )
System.out.println( "parseClientData.Error: " + e );
My problem:
The above method (parseClientData) is getting called over and over again - it is stuck in an infinite loop.
And this error is caught in the above methodt:
parseClientData.Error: java.io.IOException: Stream closed
Any ideas? I have been struggling with this for far too long.
I thnik it might be to do with blocking and non-blocking input streams.
When i used a noraml BufferedReader - i didn't have this problem.
Thanks.
Regards, Custom
Message was edited by:
custom
Message was edited by:
custom
Come on buddy wake up!
You have a while loop that NEVER exits and exception blocks that don't do anything productive and this error message "ClientData.Error: java.io.IOException: Stream closed" tells you exactly what the problem is.
Do you think maybe you should exit the while loop if an exception is thrown? Do you? Perhaps? Maybe?
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* This method sends itself into the server using compressed input/output
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ObjectOutputStream out = null;
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GZIPInputStream gis = null;
ObjectInputStream in = null;
try {
SSLSocketFactory sslFact = (SSLSocketFactory) SSLSocketFactory
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server = (SSLSocket) sslFact.createSocket(hostname, port);
String set[] = new String[] { "SSL_RSA_WITH_NULL_MD5" };
server.setEnabledCipherSuites(set);
server.setReceiveBufferSize(48000);
server.setSendBufferSize(48000);
if (milisecTimeout != 0) {
server.setSoTimeout(milisecTimeout);
gos = new GZIPOutputStream(server.getOutputStream());
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// /* Can we actually send ourselves and then receive ourselves?*/
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out.flush();
bos.flush();
gos.finish();
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// TODO Auto-generated catch block
e.printStackTrace();
gos = null;
if (out != null) {
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} catch (IOException e) {
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e.printStackTrace();
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e.printStackTrace();
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Exception:
java.io.NotSerializableException: java.io.BufferedOutputStream
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+ at com.inetmon.jn.core.internal.CaptureEngine.sendDataBackToServer(CaptureEngine.java:1420)+
+ at com.inetmon.jn.core.internal.CaptureEngine$4.actionPerformed(CaptureEngine.java:2384)+
+ at javax.swing.Timer.fireActionPerformed(Timer.java:271)+
+ at javax.swing.Timer$DoPostEvent.run(Timer.java:201)+
+ at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)+
+ at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)+
+ at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)+
+ at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)+
+ at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)+
received is null
+ at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)+
+ at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)+
The constructor which only be called once.
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int port) {
this.cookie = cookie;
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this.id = id;
this.information = information;
this.hostname = hostname;
this.port = port;
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server.setSendBufferSize(48000);
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Of course, I checked the administration interface on the rented server to see if this was due to a cpu/ram/bandwitdh problem. With no success: with 10 viewers connected, the app uses less than 1% of the cpu power, something like 200kb of RAM, and a bandwidth of 3-4Mbps (which is still under the actual bandwidth capacity of the server).
That's why I came to the conclusion that my java app was not as good as I thought, and decided to show it to you, so you can help me make it better.
So here is a schema showing the classes and their interactions:
http://www.bf-stream.com/schema2.gif
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this.setChanged();
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package com.RR4;
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"file1",
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this.notifyObservers(bufferToSend);
} else
this.notifyObservers(buffer);
this.setChanged();
} else {
try { Thread.sleep(100); } catch (Exception exp) {}
} catch (Exception exp) {
exp.printStackTrace();
try { stream.close(); } catch (Exception exp) {}
initStream();
StreamServer.java:
package com.RR4;
import java.net.ServerSocket;
public class StreamServer extends Thread {
private ServerSocket serverSocket;
private boolean socketOpened;
private StreamRelay parent;
* StreamServer: server listening for new StreamClient
public StreamServer(StreamRelay parent, int relayPort) {
this.parent = parent;
try {
serverSocket = new ServerSocket(relayPort);
socketOpened = true;
} catch (Exception exp) {
exp.printStackTrace();
socketOpened = false;
public void run() {
try {
while (socketOpened) {
parent.addClient(serverSocket.accept());
} catch (Exception exp) {
exp.printStackTrace();
StreamClient.java:
package com.RR4;
import java.net.Socket;
import java.util.Observer;
import java.util.Observable;
import java.io.*;
* StreamClient: class representing spectators connected to view the video content
* whether it is live content, or local files
public class StreamClient implements Observer {
private Socket socket;
private OutputStream outStream;
private boolean connected = true;
private StreamRelay parent;
public StreamClient(StreamRelay parent, Socket socket) {
this.parent = parent;
this.socket = socket;
try {
// initialises OutputStream from socket
outStream = socket.getOutputStream();
} catch (Exception exp) {
try { outStream.close(); } catch (Exception e) {}
try { socket.close(); } catch (Exception e) {}
exp.printStackTrace();
connected = false;
if (connected) {
// if initializing of OutputStream didn't fail
// add this class to StreamBroadcast 'clients' vector
// and add this class to StreamRelay observers
parent.clients.add(this);
parent.addObserver(this);
* update: actually send read bytes to the client
public void update(Observable observable, Object obj) {
try {
outStream.write( (byte[]) obj);
outStream.flush();
} catch (Exception exp) {
// if read bytes couldn't be sent
// remove this client from clients list and observers of StreamRelay
// and try to close OutputStream and Socket
connected = false;
try { parent.deleteObserver(this); } catch (Exception e) {}
try { parent.clients.remove(this); } catch (Exception e) {}
try { outStream.close(); } catch (Exception e) {}
try { socket.close(); } catch (Exception e) {}
LiveServer.java:
package com.RR4;
import java.net.ServerSocket;
* LiveServer:
* SocketServer listening to new 'Live streams'
public class LiveServer extends Thread {
private ServerSocket liveSocket;
private boolean liveServerOpened;
private StreamRelay parent;
public LiveServer(StreamRelay parent, int livePort) {
this.parent = parent;
try {
liveSocket = new ServerSocket(livePort);
liveServerOpened = true;
} catch (Exception exp) {
exp.printStackTrace();
liveServerOpened = false;
public void run() {
LiveStream liveStream;
try {
while (liveServerOpened) {
liveStream = new LiveStream(parent, liveSocket.accept());
new Thread(liveStream).start();
} catch (Exception exp) {
exp.printStackTrace();
LiveStream.java:
package com.RR4;
import java.util.Observable;
import java.io.*;
import java.net.Socket;
* LiveStream:
* Socket receiving live content from another distant computer
* to display it instead of the local files.
public class LiveStream extends Observable implements Runnable {
private InputStream stream;
boolean streamOpened;
private StreamRelay parent;
public LiveStream(StreamRelay parent, Socket socket) {
this.parent = parent;
this.addObserver(parent);
try {
stream = new BufferedInputStream(socket.getInputStream(), StreamRelay.BUFFER_SIZE);
streamOpened = true;
} catch (Exception exp) {
exp.printStackTrace();
streamOpened = false;
public void run() {
byte[] buffer = new byte[StreamRelay.BUFFER_SIZE];
byte[] bufferToSend;
int actualBufferSize = 0;
try {
this.setChanged();
// Bytes are read until the buffer is actually filled with BUFFER_SIZE bytes
// Only then is it sent to the observer...
while (streamOpened && ((actualBufferSize = stream.read(buffer, 0, StreamRelay.BUFFER_SIZE)) > 0)) {
if (!parent.streamFromSocket)
parent.streamFromSocket = true;
if (parent.clients.size() > 0) {
if (actualBufferSize<StreamRelay.BUFFER_SIZE) {
bufferToSend = new byte[actualBufferSize];
System.arraycopy(buffer, 0, bufferToSend, 0, actualBufferSize);
this.notifyObservers(bufferToSend);
} else
this.notifyObservers(buffer);
this.setChanged();
} else
try { Thread.sleep(100); } catch (Exception exp) {}
} catch (Exception exp) {
exp.printStackTrace();
} finally {
try { stream.close(); } catch (Exception exp) {}
this.deleteObserver(parent);
parent.streamFromSocket = false;
}For your information, I uses NSV/VP6 vbr as video codec (but this should have no incidence on it, since the app only takes the video stream from a socket and broadcasts it to other sockets, without analysing it or modifying it). And the java app is hosted on a Celeron 2.6 GHz, 128MB RAM.
I really hope you'll be able to help me with this project, as it is really important to me...
I've been trying several Stream types available with the JDK but I hadn't any success... I've also been playing with the BUFFER_SIZE parameter, unsuccessfully too...
Anyway, thanks in advance for reading me so far... and I hope, for helping me... I know the java community is strong, and I hope I won't have to make it with C or C++ :(Hi again :)
I've been focusing on the local part of the stream (no live video, just playing local files and sending them to clients) using NIO.
NIOStreamRelay.java:
package com.RR4;
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.channels.spi.*;
import java.net.*;
import java.util.*;
public class NIOStreamRelay {
static int BUFFER_SIZE = 1024;
LocalFile localFile;
Vector clients;
public NIOStreamRelay() throws IOException {
localFile = new LocalFile(this);
new Thread(localFile).start();
clients = new Vector();
acceptConnections();
public void acceptConnections() throws IOException {
// Selector for incoming requests
Selector acceptSelector = SelectorProvider.provider().openSelector();
// Create a new server socket and set to non blocking mode
ServerSocketChannel ssc = ServerSocketChannel.open();
ssc.configureBlocking(false);
// Bind the server socket to the local host and port
InetAddress lh = InetAddress.getLocalHost();
InetSocketAddress isa = new InetSocketAddress(lh, 8080);
ssc.socket().bind(isa);
// Register accepts on the server socket with the selector. This
// step tells the selector that the socket wants to be put on the
// ready list when accept operations occur, so allowing multiplexed
// non-blocking I/O to take place.
SelectionKey acceptKey = ssc.register(acceptSelector, SelectionKey.OP_ACCEPT);
int keysAdded = 0;
// Here's where everything happens. The select method will
// return when any operations registered above have occurred, the
// thread has been interrupted, etc.
while ((keysAdded = acceptSelector.select()) > 0) {
// Someone is ready for I/O, get the ready keys
Set readyKeys = acceptSelector.selectedKeys();
Iterator i = readyKeys.iterator();
// Walk through the ready keys collection and process date requests.
while (i.hasNext()) {
SelectionKey sk = (SelectionKey)i.next();
i.remove();
// The key indexes into the selector so you
// can retrieve the socket that's ready for I/O
ServerSocketChannel nextReady = (ServerSocketChannel)sk.channel();
// Accept the date request and send back the date string
Socket s = nextReady.accept().socket();
OutputStream socketStream = s.getOutputStream();
StreamClient newClient = new StreamClient(socketStream, this);
localFile.addObserver(newClient);
clients.add(newClient);
public static void main(String[] args) {
try {
NIOStreamRelay streamRelay = new NIOStreamRelay();
} catch (Exception e) {
e.printStackTrace();
LocalFile.java:
package com.RR4;
import java.util.Observable;
import java.io.*;
* LocalFile: class reading local file when no live content is sent to the relay
public class LocalFile extends Observable implements Runnable {
// filenames is an array containing a list of files to be read when no live content is sent
private String[] filenames = {
"test.nsv",
"test2.nsv"
private InputStream stream;
boolean streamOpened;
int fileIndex;
NIOStreamRelay parent;
// Constructor: initialises LocalFile
// sets fileIndex to 0, and sets main StreamRelay as Observer
public LocalFile(NIOStreamRelay parent) {
this.parent = parent;
fileIndex = 0;
initStream();
* initStream: initialises stream to read the next file in 'filenames' array
public void initStream() {
try {
stream = new BufferedInputStream(new FileInputStream(filenames[fileIndex]), NIOStreamRelay.BUFFER_SIZE);
streamOpened = true;
fileIndex++;
if (fileIndex==filenames.length)
fileIndex = 0;
} catch (Exception exp) {
exp.printStackTrace();
streamOpened = false;
* run: main loop of the class.
* the file is actually read: a buffer of BUFFER_SIZE is filled and sent to
* the observer (StreamRelay)
public void run() {
byte[] buffer = new byte[NIOStreamRelay.BUFFER_SIZE];
byte[] bufferToSend;
boolean quit = false;
int actualBufferSize = 0;
while (!quit) {
try {
this.setChanged();
// Bytes are read until the buffer is actually filled with BUFFER_SIZE bytes
// Only then is it sent to the observer...
while (streamOpened && ((actualBufferSize = stream.read(buffer, 0, NIOStreamRelay.BUFFER_SIZE)) > 0)) {
if (parent.clients.size() > 0) {
if (actualBufferSize<NIOStreamRelay.BUFFER_SIZE) {
bufferToSend = new byte[actualBufferSize];
System.arraycopy(buffer, 0, bufferToSend, 0, actualBufferSize);
this.notifyObservers(bufferToSend);
} else
this.notifyObservers(buffer);
this.setChanged();
} else {
try { Thread.sleep(100); } catch (Exception exp) {}
} catch (Exception exp) {
exp.printStackTrace();
try { stream.close(); } catch (Exception exp) {}
initStream();
StreamClient.java:
package com.RR4;
import java.io.*;
import java.net.*;
import java.util.*;
public class StreamClient implements Observer {
OutputStream out;
NIOStreamRelay parent;
public StreamClient(OutputStream out, NIOStreamRelay parent) {
this.out = out;
this.parent = parent;
public void update(Observable observable, Object obj) {
try {
out.write( (byte[]) obj);
out.flush();
} catch (Exception exp) {
// if read bytes couldn't be sent
// remove this client from clients list and observers of StreamRelay
// and try to close OutputStream and Socket
try { parent.localFile.deleteObserver(this); } catch (Exception e) {}
try { parent.clients.remove(this); } catch (Exception e) {}
try { out.close(); } catch (Exception e) {}
}Does it look better to you?
I know I'm still using single threading, but as the IO should be non-blocking, I guess it should be better.
Furthermore, I tried it locally, and was able to launch 30+ clients without buffering problems (huh, ok, my cpu here is only a 1.6GHz, so the display was a bit lagguy, but it didn't seem to buffer at all) -
How to make a peer to peer connection in a network using sockets
My Project is about a multi agent meeting scheduling system.. I've kept the DB in the server and I only use the server to retrieve data from the database. I have used sockets to communicate with the server.
Each peer in the network is an agent for a perticular user and these agents will be communicating with each other for negotiation purposes..
The problem I have is that, I couldnt communicate wit other peers using sockets.. I couldnt find any sample java code of sockets to overcum this problem.f sumone has a sample code plz send me.
And if there is a more efficient and easy way I can connect these peers except sockets, plz tell me and if u have a sample java code plz be kind enough to send.
This is my final year project in the University
Thank you
Sajini De Silva ([email protected])Hi Sajinidesilva,
I think you'll find more support in the [JXTA Community|https://jxta.dev.java.net/] for your project. Also, there's an interesting article to start with : [Introduction to the Peer-to-Peer Sockets Project|http://www.onjava.com/pub/a/onjava/2003/12/03/p2psockets.html]. -
Two applications wants to read on the same port using Socket
I have an application running on one machine using TCP/IP socket. The data transfer with the other application on other machine is in ASCII.
Now I want a new application that can have a copy of data received and sent on the given port, where the previous application is running.
Is it possible in Java using socket and TCP/IP to have two application reading data from the same port and both can read all the data.Even when you don't state the type of app which need to read the data stream (is it a server or a client app???), it's impossible to share a single TCP/IP socket among multiple apps.
Perhaps the best thing to do is to develop something like a proxy server who listens on the nominated port and provides to contact (if your apps are server ones) or to be contacted (if your apps are client ones) by the desired apps.
This way, the only job for the proxy is to duplicate the contents of the data stream and make them available to all the apps engaged.
Hope this helps. -
Using StreamConnection with MMAPI emulator
Hi,
I am using StreamConnection class to establish a socket connection with my server. If I run the application on PalmOS PDA it works fine. But when I run it in the mobile media emulator it does not connect to the server.
Does anyone know why?
These are the things I tried:
1. I tried using HttpConnection instead of StreamConnection and the application is able to connect to the server on the mmapi emulator but unable to retrieve data (as I wrote teh program keeping StreamConnection in mind....this probably can be fixed, but I wanted to make it work with the StreamConnection class using sockets so that I dont have to change my programs.)
2. I checked to see if the StreamConnection class files are present in the api zip file and I found all io classes in this zip file emptymmapi.zip
I really dont know why it wouldn't connect using StreamConnection....
Any answers would be really appreciated....The StreamConnection undoubtedly exists but sockets might not be supported.
MIDP doesn't require sockets to be implemented so maybe opening a socket connection (socket://url:port) is impossible. Aren't you getting some "Connection scheme not supported" type exception when trying to create the StreamConnection?
Maybe you are looking for
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