Java Thread - difficulty while passing value from parent to child thread

Question

Hi All,
I am calling a java program from a unix script .
My oblectives are
1)to pass value from scripts to main java class
2)main class should create a child thread and pass data to child and should return control back to script
3)child thread should run independtly of parent
The calling unix script is part of process and hence should return control back to its calling script immediately.
Findings
1)Without passing data thru setter getter /constructor method to child thread my objectives are met
2)When I pass the data from parent thread to child thread calling unix scripts wait till child thread finishesh its working
call.scr
java Main <list of Arguments>
Main.java
public class Main
             public static void main(String args[]) throws Exception
             String data2="Z";
             String data1=null;
             for(int i=0;i<args.length;i++)
                  data2=data2+","+args;
data1=data2;
Child cu=new Child();
cu.setData(data1);
data2=null;
data1=null;
cu.start();
Child.javaclass Child extends Thread
public String data;
void setData(String data)
this.data=data;
public void run()
----------> processing on data
I think due to passing of data from parent thread to child thread (Inter thread data communication/Inter process communication)
  the threads are not working as desired.
Plz anybody can suggest something.....
Thanx.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

aschin,
You seem to be confusing Java Threads with Operating System Processes.
If you want you're java program to run in the unix background then you'll need to run it in the unix background. Java (being o/s agnostistic) doesn't provide process manipulation functionality (which would include the ability to throw itself into the background, as a C program can) in the standard API, and it's hard to imagine any third party producing anything as low level as a process controler... so yeah, just start the java program in the background... and you'll need to workout some interprocess communication protocol... named pipes have worked well for me in the past, as they doesn't suffer from the quit same performance issues as real disk files.
Good luck. Keith.