Java sockets and winsock

when I use java socket to talk to my proxy, without going through a winsock, my java applet runs fine. However, when I patch winsock in between my java gui and my other proxy, I dont receive anything in the gui. I snoop at packets coming from my other proxy through winsock to my gui and the data is all there. I just cannot receive it.
I use java class DatagramSocket() to establish a socket connection and use class DatagramPacket to get the packets coming. This works if I dont go through a ms proxy.
Can anyone tell me why?

How can you snoop at packets comming? I need to know so bad. :-)
Thank you

Similar Messages

Java sockets and raw sockets

Hello!
I have made my own file sharing program with Java sockets
and i have read a litle bit about raw sockets also.
What are the differences between Java sockets and raw sockets?

raw socket can have packet types which Java does not.
Generally if you need something useful which Java cannot do there is a utility already written which does what you want, e.g. ping and you can call that.

Java Sockets and Output Streams

Hi All,
I am beginning sockets programming and I have a problem. If there is a server listening in the background for incoming connections and say for example 4 client programs programs which we shall call client1...client4 connect. How best can I capture the output streams associated with these newly created sockets so that the server can send back isome nformation to say clients1 and client4 only which is not seen by clients 2 and 3. Similarly I would like the server to send some infor to clients 2 and 3 only which is not seen by client1 and client 4.
Currently I have the server listening part as shown below, but not too sure how to add DISTINCT output streams for 1 and 4 on one hand and 2 and 3 on the other.
Thanks:
// bind socket to a port number
ServerSocket serverSocket = new ServerSocket(portNo);
// create socket to listen to client connection
while (true) {
//listen to an incoming connection
System.out.println("chatroom server waiting for incoming connections");
Socket incomingSocket = serverSocket.accept();
//launch new thread to take care of new connection
chatRoomThread chatThread = new chatRoomThread(incomingSocket);
chatThread.start();
//go back and wait for next connection
Please help.
Thanks,
Bleak

HouseofHunger wrote:
yes thats exactly the way I have my in and out streams, in the run method, but that doesn't help me in filtering traffic, in other words I am saying 2 clients, client1 and client4 for example should share a common in and out stream so that they will see eact other's messages... makes sense.....?No, doesn't make sense. That's the wrong design. Each socket should have its own input and output stream (yes, I know, that's been said several times before). If messages going to client1 should also be sent to client4, then whatever writes the messages to client1's output stream must also write them to client4's output stream. Trying to make those two output streams actually be the same output stream is the wrong way to do that. Just have the controller send the messages to whoever is supposed to get them.

Java WD and Socket Communication

Hi,
Is it possible to use Java Socket Communication with Java Web Dynpro. Or if not what is the best approach to have a Java Socket program integrated with a Web Dynpro Communication.
Basically, I have an application which provides API for communication via Java Sockets.And this needs to be integrated in our SAP application.
Thanks,
CD

Hi,
You are currently using JCO to "Connect to a Remote System" - JCO will connect to a back-end with the main purpose of "executing BAPI's" in it.
When you move to WebDynpro, you have what SAP calls Adaptive RFC Model - this will create a "Model Entity" in you WD Project that will do the same thing your JCO does.
Assume your JCO now calls "BAPI_GET_FLIGHTS", to return the Flights that are currently available - In your newly create WDP Project, you will manually specify what back-end you wanna use when "Importing" and you will tell also the BAPI name. WDP will generate the class structure that you need in order to execute that function.
JCO is what SAP created to execute BAPI's. JCO can be used by any "Java" like application that needs to connect to the back-end. But when you move to WDP, you don't need to use this anymore - You will use WDP Models.
Youi will still need your JCO Destinations created in the Application Server, so behind the scenes WDP creates a "layer" so you don't need to code the JCO calls manually.
Regards,
Daniel

Java Sockets - help with using objects

I am new to java sockets, and need to come up with a way to send a user defined instance of a class across a basic client/server application.
I can not find out how to do this. I read the tutorials, but my class can not be serialized. How can I send/recieve this instance of a user defined class?

right off the top of my head, doesn't serialver just spit out a UID for a given set of classes?
To mark a class as Serializable, just implement the java.io.Serializable class - then you could use the readObject/writeObject methods of the ObjectInputStream/ObjectOutputStream classes.
Good luck
Lee

Java socket run on localhost against outside server

Hi everyone,
I am newbie to Java socket and networking. By spending this weekend over the internet reading and researching I have made my first Server-Client java socket program run sucessfully on my localhost 127.0.0.1. They can be connected and ok to communicate.
However, when I put my server program to the LIVE server outside the network the client side says cannot connect to the server because: Connection Error, Connection refused: connect. So I read some stuff about firewall and NAT on the web but i was shamed that I don't understand there is any solution to this.
It is great appreciated if someone can point me out how can I resolve this or make a step out because I am running out of time to give out the program against the deadline. But I really thank you anyone has been reading this.
The server code:
* To change this template, choose Tools | Templates
* and open the template in the editor.
package instantmessenger;
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
    public class Server extends JFrame implements ActionListener {
        JTextArea textreceive   =new JTextArea();
        JTextArea textsend      =new JTextArea();
        JButton button          =new JButton("Send");
        BufferedReader in;
        PrintWriter out;
        public Server () {
                //init   controls
                setTitle("Server");
                setBounds(50,50,500,400);
                getContentPane().setLayout(null);
                getContentPane().add(textreceive);
                getContentPane().add(textsend);
                getContentPane().add(button);
                textreceive.setBounds(10,10,450,300);
                textsend.setBounds(10,320,350,30);
                button.setBounds(370,320,70,30);
                button.addActionListener(this);
        public void listenClient() throws IOException {
                ServerSocket   server=new   ServerSocket(9999);
                System.out.println("start:"+server);
                textreceive.append("start"+server+"\n");
                try {
                        Socket s = server.accept();
                        try {
                                System.out.println("connecting   :"+s);
                                textreceive.append("connecting   :"+s+"\n");
                                in = new BufferedReader(new InputStreamReader(s.getInputStream()));
                                    out=new   PrintWriter(
                                    new   BufferedWriter(
                                    new   OutputStreamWriter(s.getOutputStream())));
                                out = new PrintWriter(s.getOutputStream());
                                String str=null;
                                while(true) {
                                        str = in.readLine();
                                        System.out.println(str);
                                        textreceive.append(str+"\n");
                        finally {
                            s.close();
                finally {
                    server.close();
        } // end function
        public void actionPerformed(ActionEvent event) {
                String str = textsend.getText();
                if( !str.equals("")) {
                        out.println(textsend.getText());
                        //out.println(textsend.getText());
                        out.flush();
                        textreceive.append(textsend.getText()+"\n");
                        textsend.setText("");
        } // end function
        public   static   void   main(String   args[])   throws   IOException {
            Server   s=new   Server();
            s.show();
            s.listenClient();
        } // end function
    } // end classThe client source code:
package instantmessenger;
    import   java.net.*;
    import   java.io.*;
    import   javax.swing.*;
    import   java.awt.*;
    import   java.awt.event.*;
    public   class   Client   extends   JFrame implements   ActionListener {
        JTextArea   textreceive=new   JTextArea();
        JTextArea   textsend   =new   JTextArea();
        JButton     button   =new   JButton   ("Send");
        BufferedReader in;
        PrintWriter     out;
        public Client(){
                //init   controls
                setTitle("Client");
                setBounds(50,50,500,400);
                getContentPane().setLayout(null);
                getContentPane().add(textreceive);
                getContentPane().add(textsend);
                getContentPane().add(button);
                button.addActionListener(this);
                textreceive.setBounds(10,10,450,300);
                textsend.setBounds(10,320,350,30);
                button.setBounds(370,320,70,30);
       } // init
        public void startNet() throws IOException {
              //Socket client=new Socket("localhost",9999);
              Socket client=new Socket("222.33.444.5555",9999); // NOT REAL SERVER IP
              try {
                      System.out.println("Socket="   +client);
                      in    =   new BufferedReader(new InputStreamReader(client.getInputStream()));
                      out   =   new PrintWriter(new BufferedWriter(new OutputStreamWriter(client.getOutputStream())),true);
                      String str=null;
                      while(true) {
                          str   =   in.readLine();
                          System.out.println(str);
                          textreceive.append(str+"\n");
              finally {
                    client.close();
        } // end function
        public void actionPerformed(ActionEvent   event) {
            String str=textsend.getText();
            if(!str.equals("")) {
                out.println(textsend.getText());
                //out.println(textsend.getText());
                out.flush();
                textreceive.append(textsend.getText()+"\n");
                textsend.setText("");
        } // function
        public static void main(String args[]) throws IOException {
            Client c=new Client();
            c.show();
            c.startNet();
        } // function
} // end classThank you
Morris Lee

However, when I put my server program to the LIVE server outside the network the client side says cannot connect to the server because: Connection Error, Connection refused: connect. So I read some stuff about firewall and NAT on the web but i was shamed that I don't understand there is any solution to this.What do you want us to do? You already know that the problem probably is that you need to open port 9999 in the firewall, and you probably also need to configure it for port forwarding.
Most clients will be able to connect after that, but some might still have problems. E.g. some companies don't allow clients to connect to other ports than a few well known ones (e.g. 21, 80 and 443)

Error in the Socket Communication between Java Client and VC++ Server

In my application, using Java Client to do socket bi-communication with VC++ Server, which is done by somebody else.
The error is after the application properly running one or two days, the VC++ Server cannot receive the messages passed by java Client, but at Java client, everything is the same, although using CheckError() after every print(), there is no exception thrown.
The JVM is jdk1.3.1, platform is Win2k Server.
The outputstream is PrintWriter().
Please help me to settle down this problem. Thanks in advance.

I read some thread in the forum, and found somebody had the similar problem with me. Just want to know how to settle this problem.
In the client/server program. Client is a JAVA program and Server a
VC++ program. The connection works, and the problem appears after some time. The Client sends a lots of requests to Serverm, the server seems receive nothing. But at the same time, the server is able to send messages to Client. The Client also can get the messages and handle them. Don't understand why there this problem and why it appears when it wants.
The client is a Win2k platorm with JDK1.3.1 and the server is also a Win2K platform with VC++ 6.0.
In the Client, using:
inputFromServer = new BufferedReader(new InputStreamReader(socket.getInputStream()));
outputToServer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
Hope can get your help.

C# socket and java socket

hello
i am a java programmer,recently we got a project,that need the c# app to communicate with java app ,i select the socket as intermediate.
i notice that java socket term is divided into " blocking" and "non-blocking",the latter come from jdk1.4, the c# socket is devided into "synchronized" and "asynchronized" and both of them are blocking,
in my project,i have tried synchronized c# socket coorperating to blocking java socket,it works well..but when i modify the c# app to ASYNCHRONIZED socket,my system DON'T works well,i don't know why? i can't find asynchronized socket in java,.i learn that nio socket is nonblocking, is it asynchronized?
who can tell me what's is the best solution for the socket communication between java and c#?

yes,i have read them,but it only tell me the communication between java apps,and DON'T tell me any clue about c# socket.

Need help on Socket and HTTP

Hi,
I need help ... please ... I have to use socket and not HTTPURLConnection
I try to connect with a socket to a web server (apache2) and request one page but two times.
The first time it works well but the second one it doesn't ... I get a null message.
Why ?
Does the server close the socket as soon as the page is sent ?
If it doesn't how I can continue sending and receiving data on the same socket ?
Here is my code:
package test;
import java.net.*;
import java.io.*;
public class Test
private String laRequete = new String(
"POST http://localhost:5577/Test/ HTTP/1.0\r\n"+
"Host:localhost:5577\r\n"+
"\r\n");
PrintWriter laSortie;
BufferedReader lEntree;
Socket laSocketTCP;
public Test()
String tmp;
try
laSocketTCP = new Socket("localhost", 5577);
laSortie = new PrintWriter(laSocketTCP.getOutputStream());
lEntree = new BufferedReader(new InputStreamReader(laSocketTCP.getInputStream()));
laSortie.println(laRequete);
laSortie.flush();
// Premier essai OK
System.out.println(lEntree.readLine());
while((tmp = lEntree.readLine()) != null)
System.out.println(tmp);
// Second essai => Not OK
laSortie.println(laRequete);
laSortie.flush();
System.out.println(lEntree.readLine());
while((tmp = lEntree.readLine()) != null)
System.out.println(tmp);
catch (Exception e)
e.printStackTrace();
public static void main(String args[])
Test tp = new Test();
Here is the result of the execution
HTTP/1.1 200 OK
Date: Wed, 29 Sep 2004 08:35:35 GMT
Server: Apache/2.0.51 (Win32)
Last-Modified: Wed, 29 Sep 2004 08:27:57 GMT
ETag: "23a46-9a-56c93f9a"
Accept-Ranges: bytes
Content-Length: 154
Connection: close
Content-Type: text/html; charset=ISO-8859-1
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> Index Test 1 </TITLE>
</HEAD>
<BODY>
Test 1
</BODY>
</HTML>
null
Thanks, bye.

Send an HTTP 1.1 request instead of a 1.0 request.
HTTP 1.0 does not support keeping the connection open, so yes, the server closes the connection.
Dave.

Conflict between socket and RMI

Hi
I wrote a program in client-server using socket and it was fine. I also wrote a client-server program using RMI. Fine as well. But after I connected the client-server using socket (open socket, send-receive messages, close socket), then use RMI. I got java.rmi.NotBoundException.
Would anyone have a look and provide your feedback please? Thanks.
big J
*****************this is Server.java ***************************
package single;
import java.io.*;
import java.rmi.Naming;
import java.rmi.RemoteException;
import java.net.*;
import java.rmi.*;
public class Server
extends Thread {
public static final int SOCKETPORT = 5555;
private String serverName;
public Server() throws IOException {
System.out.println("*** socket opened ***");
serverName = new String("localhost");
ServerSocket serverSocket = new ServerSocket(SOCKETPORT);
Socket socket = serverSocket.accept();
InputStream is = socket.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
System.out.println(bufferedReader.readLine());
OutputStream os = socket.getOutputStream();
PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(os), true);
printWriter.println("from server");
os.close();
is.close();
socket.close();
System.out.println("*** socket closed ***");
public void runServer() {
System.out.println("*** start of run():RMI ***");
System.setSecurityManager(new SecurityManager());
try {
RMIInterfaceImpl rMIInterfaceImpl = new RMIInterfaceImpl();
Naming.bind("//" + serverName + ":9999/RMIInterface", rMIInterfaceImpl);
catch (RemoteException ex) {
catch (MalformedURLException ex) {
catch (AlreadyBoundException ex) {
System.out.println("*** end of run():RMI ***");
public static void main(String args[]) throws Exception {
Server server = new Server();
server.runServer();
******************this is Client.java **************************
package single;
import java.io.*;
import java.net.*;
import java.rmi.Naming;
public class Client {
private String serverName;
private final static int SOCKETPORT = 5555;
public Client() throws IOException {
serverName = new String("localhost");
Socket socket = new Socket(serverName, SOCKETPORT);
OutputStream os = socket.getOutputStream();
PrintWriter printWriter=new PrintWriter(os, true);
printWriter.println("from client");
InputStream is = socket.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
System.out.println(bufferedReader.readLine());
is.close();
os.close();
socket.close();
public void runClient() throws Exception {
System.out.println("*** start of runClient():RMI ***");
System.setSecurityManager(new SecurityManager());
RMIInterface rMIInterfaceImpl = (RMIInterface) Naming.lookup(
"//" + serverName + ":9999/RMIInterface");
String str = rMIInterfaceImpl.print();
System.out.println(str);
rMIInterfaceImpl.serverSide();
System.out.println("*** end of runClient():RMI ***");
public static void main(String args[]) throws Exception {
Client client = new Client();
client.runClient();
***************** this is RMIInterface.java ***********************
package single;
import java.rmi.Remote;
import java.rmi.RemoteException;
interface RMIInterface
extends Remote {
String print() throws RemoteException;
void serverSide() throws RemoteException;
********************* this is RMIInterfaceImpl.java ***************
package single;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
public class RMIInterfaceImpl
extends UnicastRemoteObject
implements RMIInterface {
public RMIInterfaceImpl() throws RemoteException {}
public String print() {
return new String("hello world");
public void serverSide(){
System.out.println("this should appear in serverside");

I think you have a timing problem between your client and server. As soon as your client and server programs have finished their socket communication, they will both do their "runServer"/"runClient" methods. If the client attempts to lookup the server before the server has registered itself via Naming.bind(), I would expect that's why you're getting a NotBoundException in the client.
You probably wouldn't use the design of your test client/server for something significant, but a quick and dirty way to make this work might be to have the client call Thread.sleep() for a few seconds before trying to do the lookup.

Problem with the socket and the standard output stream

Hy, I have a little problem with a socket program. It has the server and the client. The problem is that the client at one point in the program, cannot print messages in the console.
My program does the next: the server waits connections, when a client connects to it, the server gets outputstream to the socket and writes two strings on it. Meanwhile, the client gets the inputstream to the socket and reads on it with a loop the two strings written by the server . The strings are printed by the client in the console. The problem starts here; once the read strings are printed ,I mean, after the loop, there are other System.out.println in the client but the console doesnt print anything . It curious that only when I comment on the server code the line that says: "br.readLine()" just before the catch, the client prints all the System.out.println after the loop but why?
Here is the code:
Server code:
public class MyServerSocket {
public MyServerSocket() {
try{
ServerSocket server= new ServerSocket(2000);
System.out.println("servidor iniciado");
Socket client=server.accept();
System.out.println("Client connected");
OutputStream os=client.getOutputStream();
PrintWriter pw= new PrintWriter(os);
String cadena1="cadena1";
String cadena2="cadena2";
pw.println(cadena1);
pw.println(cadena2);
pw.flush();
InputStream is=client.getInputStream();
InputStreamReader isr= new InputStreamReader(is);
BufferedReader br= new BufferedReader(isr);
br.readLine(); //If a comment this line, the client prints after the loop, all the System.out....
catch (IOException e) {
// TODO: handle exception
public static void main(String[] args) {
new MyServerSocket
Client code:
public class MyClientSocket {
public MyClientSocket () {
try{
Socket client= new Socket("localhost",2000);
InputStream is=client.getInputStream();
InputStreamReader isr= new InputStreamReader(is);
BufferedReader br= new BufferedReader(isr);
String read;
while((read=br.readLine())!=null){
System.out.println(read);
//These messages are not printed unless I comment the line I talked about in the server code
System.out.println("leido");
System.out.println("hola");
}catch (IOException e) {
public static void main(String[] args) {
new MyClientSocket
}

You are right but with this program the loop ends. As you see, the first class, the Server, writes to the socket one text file. The second class, the client, reads the text file in his socket written by the server and writes it to a file in his machine.
NOTE: The loop in the client ends and the server doesnt make any close() socket or shutdownOutput() .
public class ServidorSocketFicheromio {
     public ServidorSocketFicheromio() {
try{
     ServerSocket servidor= new ServerSocket(2000);
     System.out.println("servidor iniciado");
     Socket cliente=servidor.accept();
     System.out.println("cliente conectado");
     OutputStream os=cliente.getOutputStream();
     PrintWriter pw= new PrintWriter(os);
     File f = new File("c:\\curso java\\DUDAS.TXT");
     FileReader fr= new FileReader(f);
     BufferedReader br= new BufferedReader(fr);
     String leido;
     while((leido=br.readLine())!=null){
          pw.println(leido);
     pw.flush();
     }catch (IOException e) {
     * @param args
     public static void main(String[] args) {
          new ServidorSocketFicheromio();
public class ClienteSocketFicheromio {
     public ClienteSocketFicheromio() {
try{
     Socket cliente= new Socket("localhost",2000);
     File f = new File("G:\\pepe.txt");
     FileWriter fw= new FileWriter(f);
     PrintWriter pw= new PrintWriter(fw);
     InputStream is=cliente.getInputStream();
     InputStreamReader isr= new InputStreamReader(is);
     BufferedReader br= new BufferedReader(isr);
     String leido;
     while((leido=br.readLine())!=null){
          pw.println(leido);
          System.out.println(leido);
          System.out.println("leido");
          System.out.println("hola");
          pw.flush();
     }catch (IOException e) {
     public static void main(String[] args) {
     new ClienteSocketFicheromio();/
}

JDK 1.6 on Solaris. Multiple java processes and thread freezes

Hi, we've come across a really weird behavior on the Solaris JVM, reported by a customer of ours.
Our server application consists of multiple threads. Normally we see them all running within a single Java process, and all is fine.
At some point in time, and only on Solaris 10, it seems that the main Java process starts a second Java process. This is not our code trying to execute some other application/command. It's the JVM itself forking a new copy of itself. I assumed this was because of some JVM behaviour on Solaris that uses multiple processes if the number of threads is > 128. However at the time of spawn there are less than 90 threads running.
In any case, once this second process starts, some of the threads of the application (incidentally, they're the first threads created by the application at startup, in the first threadgroup) stop working. Our application dumps a list of all threads in the system every ten minutes, and even when they're not working, the threads are still there. Our logs also show that when the second process starts, these threads were not in the running state. They had just completed their operations and were sleeping in their thread pool, in a wait() call. Once the second process starts, jobs for these threads just queue up, and the wait() does not return, even after another thread has done a notify() to inform them of the new jobs.
Even more interesting, when the customer manually kills -9 the second process, without doing anything in our application, all threads that were 'frozen' start working again, immediately. This (and the fact that this never happens on other OSes) makes us think that this is some sort of problem (or misconfiguration) specific to the Solaris JVM, and not our application.
The customer initially reported this with JDK 1.5.0_12 , we told them to upgrade to the latest JDK 1.6 update 6, but the problem remains. There are no special JVM switches (apart from -Xms32m -Xmx256m) used. We're really at a dead end here in diagnosing this problem, as it clearly seems to be outside our app. Any suggestion?

Actually, we've discovered that that's not really what was going on. I still believe there's a bug in the JVM, but the fork was happening because our Java code tries to exec a command line tool once a minute. After hours of this, we get a rogue child process with this stack (which is where we are forking this command line tool once a minute):
JVM version is 1.5.0_08-b03
Thread t@38: (state = IN_NATIVE)
- java.lang.UNIXProcess.forkAndExec(byte[], byte[], int, byte[], int, byte[], boolean, java.io.FileDescriptor, java.io.FileDescriptor, java.io.FileDescriptor) @bci=168980456 (Interpreted frame)
- java.lang.UNIXProcess.forkAndExec(byte[], byte[], int, byte[], int, byte[], boolean, java.io.FileDescriptor, java.io.FileDescriptor, java.io.FileDescriptor) @bci=0 (Interpreted frame)
- java.lang.UNIXProcess.<init>(byte[], byte[], int, byte[], int, byte[], boolean) @bci=62, line=53 (Interpreted frame)
- java.lang.ProcessImpl.start(java.lang.String[], java.util.Map, java.lang.String, boolean) @bci=182, line=65 (Interpreted frame)
- java.lang.ProcessBuilder.start() @bci=112, line=451 (Interpreted frame)
- java.lang.Runtime.exec(java.lang.String[], java.lang.String[], java.io.File) @bci=16, line=591 (Interpreted frame)
- java.lang.Runtime.exec(java.lang.String, java.lang.String[], java.io.File) @bci=69, line=429 (Interpreted frame)
- java.lang.Runtime.exec(java.lang.String) @bci=4, line=326 (Interpreted frame)
- java.lang.Thread.run() @bci=11, line=595 (Interpreted frame)There are also several dozen other threads all with the same stack:
Thread t@32: (state = BLOCKED)
Error occurred during stack walking:
sun.jvm.hotspot.debugger.DebuggerException: can't map thread id to thread handle!
 at sun.jvm.hotspot.debugger.proc.ProcDebuggerLocal.getThreadIntegerRegisterSet0(Native Method)
 at sun.jvm.hotspot.debugger.proc.ProcDebuggerLocal.getThreadIntegerRegisterSet(ProcDebuggerLocal.java:364)
 at sun.jvm.hotspot.debugger.proc.sparc.ProcSPARCThread.getContext(ProcSPARCThread.java:35)
 at sun.jvm.hotspot.runtime.solaris_sparc.SolarisSPARCJavaThreadPDAccess.getCurrentFrameGuess(SolarisSPARCJavaThreadPDAccess.java:108)
 at sun.jvm.hotspot.runtime.JavaThread.getCurrentFrameGuess(JavaThread.java:252)
 at sun.jvm.hotspot.runtime.JavaThread.getLastJavaVFrameDbg(JavaThread.java:211)
 at sun.jvm.hotspot.tools.StackTrace.run(StackTrace.java:50)
 at sun.jvm.hotspot.tools.JStack.run(JStack.java:41)
 at sun.jvm.hotspot.tools.Tool.start(Tool.java:204)
 at sun.jvm.hotspot.tools.JStack.main(JStack.java:58)I'm pretty sure this is because the fork part of the UnixProcess.forkAndExec is using the Solaris fork1 system call, and thus all the Java context thinks all those threads exist, whereas the actual threads don't exist in that process.
It seems to me that something is broken in UnixProcess.forkAndExec in native code; it did the fork, but not the exec, and this exec thread just sits there forever. And of course, it's still holding all the file descriptors of the original process, which means that if we decide to restart our process, we can't reopen our sockets for listening or whatever else we want to do.
There is another possibility, which I can't completely rule out: this child process just happened to be the one that was fork'd when the parent process called Runtime.halt(), which is how the Java process exits. We decided to exit halfway through a Runtime.exec(), and got this child process stuck. But I don't think that's what happens... from what I understand that we collected, we see this same child process created at some point in time, and it doesn't go away.
Yes, I realize that my JVM is very old, but I cannot find any bug fixes in the release notes that claim to fix something like this. And since this only happens once every day or two, I'm reluctant to just throw a new JVM at this--although I'm sure I will shortly.
Has anyone else seen anything like this?

What is ABAP/JAVA Proxy and whats the use of it?

Hello All,
What is ABAP/JAVA Proxy. And why do we need to use them? I am not sure of the definitions given on help.sap.com. Thats the reason I am posting this question. Right answer will be rewarded. Thanks in advance.
Regards,
Farooq.

HI Farooq
ABAP Proxy
ABAP server proxy is created for the inbound interface creted in XI's Integration repository proxy should be created in the business system for which the interface is created .
U can reference following link :
http://help.sap.com/saphelp_nw2004s/helpdata/en/02/265c3cf311070ae10000000a114084/frameset.htm
Server Proxies are generated for Inbound Message Interfaces. These are used to Process the Data coming into SAP System from an external application.
Sproxy is the transaction to generate Proxies.
Plz refer to this blog on abap server proxies
/people/siva.maranani/blog/2005/04/03/abap-server-proxies
Java Proxy
Java Proxoies are used to allows your java Applications ( j2ee, j2se applications )to interact directly to the Integration Server of XI without any special adapters.
All documents are available on SDN itself .
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/7d4db211-0d01-0010-1e8e-9b07fc2113ab - How To Work with XI 3.0 Java Proxies
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/a068cf2f-0401-0010-2aa9-f5ae4b2096f9- Java Proxies and SAP XI - The Inside Story, Part 1
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/f272165e-0401-0010-b4a1-e7eb8903501d - Java Proxies and SAP XI - The Inside Story, Part 2
Proxies help you achieve non-standard functionality for which the out of box XI adapters do not suffice. Just to give you an example, consider a system with which XI has to integrate , the only interface the system offers is a TCP / IP socket based interface. You could write a Java proxy which would interact over sockets with your target system, which is not possible with other standard adapters which are shipped with your XI installation
You can refer demo on SDN TV, on this link
https://www.sdn.sap.com/irj/sdn?rid=/webcontent/uuid/110ff05d-0501-0010-a19d-958247c9f798 [original link is broken]
Cheers..
Vasu
** Reward Points if found useful **

Using plain Java Sockets(not RMI) how..?

hi!
1. Using plain Java Sockets(not RMI) how can the client detect when its server
goes down?
There is a long time interval between client requests and the client wants
to retain a live connection rather than disconnect after every reqest.
Please also cc your reply to [email protected]
Thanks,
\Raghu

If you try to send data when the host is gone, it throws an exception. I don'thow to check if it is alive though. I'm having the same problem right now.

Problems with sockets and InputsStreams

Hi,
I ve this code:
InputStream is = null;
boolean ok=true;
while(ok){
//sc is an object instance of socketConnection
is = sc.openInputStream();
return this.parse(is);
//is.close();
return "";
and this exception is produced:
java.io.IOException: no more Input Streams available.
This exception is produced in the line:
is = sc.openInputStream();
I m connecting to a server and this server sends data throw a socket... but the problem is that when i m reading from this socket and this socket doesn t have data in it...
how could i solve this problem...?
Thanks,
Diego

That would be the "real" code:
public String process()throws IOException{
InputStream is = null;
is = sc.openInputStream();
String result= this.parse(is);
is.close();
any suggestions?
Thanks,
Diego

Java sockets and winsock

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