Problem with running a program from Java file

[Oz Kron]

I am trying to run a program, the program is EXE file written in C#, it should get input from a client in Java, and write to it (simple TCP/IP)
But
When it just doesn't work!
the program get stuck and don't get any thing from the server
But
When I run the server alone (EXE from the command), and connect to it with a client, every thing works fine!
So, what is the problem with "exec" and why isn't it like running a program from the command ?
Thank you

Runtime r=Runtime.getRuntime();
String[] cmd={"DynamicInvocation.exe" , String.valueOf(_port) , name};
Process P=r.exec(cmd);
    

[Ulf Dittmer]

Runtime.exec has a few pitfalls that you need to avoid. In this case it sounds like you may not be handling the input, error and output streams of the child process. You can read all about how to do that in this article.

[Oz Kron]

Amm, but what is the problem?
I have done some of the things in the topic you have gave me, but than I can print like only one line, and when sending anther line to the server, it get stuck again like in the first time

[Ulf Dittmer]

In that case it would help to see the code you're now using.

[Oz Kron]

import java.net.Socket;
import java.net.ServerSocket;
import java.io.IOException;
import java.io.*;
import java.io.BufferedReader;
import java.io.InputStreamReader;
 
/**
 * A simple client implementation
 */
public class DllClient {
 
    protected String _host;
    protected int _port;
    protected Socket _socket;
    protected String _knowledgeFile;
 

/**
     * Creates a new DllClient object
     * @param port the server's port
 * @param name of this component
 * @param knowledgeFile to retrieve knowledge from
 * @throws java.io.IOException if the connection is bad
     */
    public DllClient(int port,String name, String knowledgeFile) {
        _host = "127.0.0.01";
        _port = port;
System.out.println("DllClient in his glory is using PORT "+port);
_knowledgeFile = knowledgeFile;
try {
Runtime r=Runtime.getRuntime();
String[] cmd={"DynamicInvocation.exe" , String.valueOf(_port) , name};
Process P=r.exec(cmd);
 
 //P.waitFor();
 BufferedWriter buffOut = new BufferedWriter(new OutputStreamWriter(P.getOutputStream())); 
 
BufferedReader buffIn = new BufferedReader(new InputStreamReader(P.getInputStream())); 
 
String s;
s = buffIn.readLine();
System.out.println("s successfully retrieved");
System.out.println("s: "+s);
 
  System.out.println("EEEEE");
  connect();
} catch (IOException e) {
e.printStackTrace();
try {
_socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
Runtime.getRuntime().exit(15);
System.exit(2933);
}
//catch (InterruptedException e1)
//{
//}
}
 
/**
     * Connects to the server
     * @throws java.io.IOException in case of a connection failure
     */
    public void connect() throws IOException {
        _socket = new Socket(_host, _port);
    }
 
    /**
     * Disconnects from the server
     * @throws java.io.IOException in the case of a disconnection failure
     */
    public void disconnect() throws IOException {
        _socket.close();
    }
    
    public boolean ack() throws IOException {
        send("ack:");
        String ans = receive();
        return ans.equals("msg:ACK");
    }
 
    /**
     * Sends a message to the server
     * @param message the message to send
     * @throws java.io.IOException in the case of sending failure
     */
    public void send(String message) throws IOException {
        _socket.getOutputStream().write(message.getBytes());
        _socket.getOutputStream().flush();
    }
 
    /**
     * Receives information from the server
     * @return the received message, or null of no message received
     * @throws java.io.IOException in the case of reception failure
     */
    public String receive() throws IOException {
        byte []buff = new byte[8192];
System.out.println("Reading");
int nBytes = _socket.getInputStream().read(buff);
System.out.println("done reading");
if (nBytes>0) {
            String ans = new String(buff, 0, nBytes);
System.out.println("Read "+ans);
return ans;
        }
        else {
System.out.println("Read "+nBytes+" chars. Blachs");
return null;
        }
    }
 
    
 
public void dispose() {
try {
send("STOP:BLA");
disconnect();
} catch (IOException e) {
e.printStackTrace();
}
}
 
public static void main(String[] args) throws IOException {
DllClient dll = new DllClient(8000, "ImplementationOne.dll", "knowledge");
System.out.println("Created a DllClient.");
dll.send("onCall :-P	 rint this, will ya?");
System.out.println("Sent to server a line");
String ans = dll.receive();
System.out.println("Received "+ans);
dll.dispose();
}
}
    

this is the code
Can some one help me out here?
Thank you

[Ulf Dittmer]

So what happens exactly if you execute this code? Also, you don't seem to be handling the error stream.
[ August 13, 2007: Message edited by: Ulf Dittmer ]

[Oz Kron]

What happen is for now that if the client send to the server one line, it kind of works, but if there are more lines, it get stuck