Java Command problem

[Amir Iqbal]

hi everyone .

i am facing a strange problem basically i want to redirect output "JAVA MYCLASS"
command to my specific file.

Description :

Actually i want to redirect the output of "JAVA MYCLASS" command.
where the MYCLASS would be the name of the compiled class at specific
location.
i tried following but got no output

   
import java.util.*;
import java.io.*;
class StreamGobbler extends Thread
{
    InputStream is;
    String type;
    OutputStream os;
    FileWriter fw;
 
    StreamGobbler()
    { 
    }
    
    StreamGobbler(InputStream is, String type)
    {
        this(is, type, null);
    }
    StreamGobbler(InputStream is, String type, OutputStream redirect)
    {
        this.is = is;
        this.type = type;
        this.os = redirect;
    }
 
    public void run()
    {
        try
        {
    fw=new FileWriter("C:/Documents and Settings/aamir/Desktop/out.txt");
            PrintWriter pw = null;
            
            if (os != null)
                pw = new PrintWriter(os);
 
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String line=null;
            while ( (line = br.readLine()) != null)
            {
                if (pw != null)
                {
                    pw.println(line);
               // System.out.println(type + ">" + line);
                fw.write(type + ">" + line);
                fw.flush();
}
            }
            if (pw != null)
                pw.flush();
            
             ExecuterClass.show(".............in exec after java cmd.............." , true);
        } catch (IOException ioe)
            {
            ioe.printStackTrace();
            }
    }
}
public class ExecuterClass2
{
    FileOutputStream fos;
    public void exec(String class_name,String path)
    {
        if (class_name.length()<=0 || class_name == null)
        {
            System.out.println("Class Name is empty");
        }
        else
        {
            try
            {
                fos = new FileOutputStream(class_name);
                Runtime rt = Runtime.getRuntime();
                
                  
                //Process proc = rt.exec("java  "+class_name+" 1>>output.txt");
                Process proc = rt.exec(cmd);
                
                // any error message?
                StreamGobbler errorGobbler = new StreamGobbler(proc.getErrorStream(), "ERROR");
                
                // any output?
                StreamGobbler outputGobbler = new StreamGobbler(proc.getInputStream(), "OUTPUT", fos);
 
                // kick them off
                errorGobbler.start();
                outputGobbler.start();
               
                // any error???
                int exitVal = proc.waitFor();
          
                fos.flush();
                fos.close();
            }
            catch (Throwable t)
            {
                t.printStackTrace();
            }
            
    }
  }
}
 
 
//**********************************************************************
  

but at the end the output.txt is empty

please help me

waiting for your suggestion

regards
Amir Iqbal

JCE: Please use Code Tags - they preserve your code format and make reading easier.
[ August 14, 2008: Message edited by: Joe Ess ]

[Joe Ess]

Your code does not compile:

    
C:\junk>javac ExecuterClass2.java
ExecuterClass2.java:51: cannot find symbol
symbol  : variable ExecuterClass
location: class StreamGobbler
             ExecuterClass.show(".............in exec after java cmd.............." , true);
             ^
ExecuterClass2.java:76: cannot find symbol
symbol  : variable cmd
location: class ExecuterClass2
                Process proc = rt.exec(cmd);
                                       ^
2 errors

Please Post Real Code.

[Amir Iqbal]

ok so please omitt that line with

System.out.println("..............");
or
basically it is a static method in ExecuterClass
********************************
ExecuterClass.show(String str,boolean b){

if (b == true)
System.out.println(str);
}

[Joe Ess]

That fixes one of the two compile errors.

[Abhijeet Nalawade]

Fail to understand what is to be achieved. Explain it bit more clearly.

[Amir Iqbal]

just comment that line..... yar it will fix all the errors... coz it is just a debugging statment....

[Joe Ess]

Are you going to fix the error on line 76?
Please Show Some Effort. I'm getting the impression that you just want us to do your work for you.

[Nitesh Kant]

Originally posted by Amir Iqbal:
just comment that line..... yar it will fix all the errors... coz it is just a debugging statment....

Joe's intention was not for him to fix your code but to make you realise the importance of Posting real code.
Anyone over here can fix your code of compilation error but the point is that you must post your question clearly.
It wastes the time of the people trying to help you if your code has compilation errors.

The other compilation error Joe is talking about isnt a debug statement, but it is the core of your program execution, you are calling

rt.exec(cmd)

when

cmd

is not defined.

ExecuterClass2.java:76: cannot find symbol
symbol : variable cmd
location: class ExecuterClass2
Process proc = rt.exec(cmd);
^

BTW, this code is directly out of this article
If you are having problems understanding some article or sample code, then please QuoteYourSources
[ August 18, 2008: Message edited by: Nitesh Kant ]