Problem with running an external program via java

**g123456** · 12-30-2009, 03:26 PM

Java Code:

import java.io.*;
import java.util.*;


public class execute {
      
	
		//main method
	public static void main(String[] args) 
	{ 
 
     try
     {
     
      Runtime rt = Runtime.getRuntime() ;

      Process p = rt.exec("duck.exe") ;
      }
      catch(IOException e)
      {
	      
	      
      }

     
      
      
  }
  
}

duck.exe is in the same folder with the java class

no compile errors, no execution errors

but the problem is that it opens it in the backround. is there some way to make execute it on the desktop and not in the background?

**travishein** · 12-30-2009, 04:27 PM

I'm not sure what is meant by on the desktop, an application launched by Java runtime will show up on the desktop of the current user if it is a graphical desktop application. Do you mean, to make it execute in a way that causes the Java application to launch it to wait for it to finish ?

The Runtime.exec() facility is now deprecated, prefering the ProcessBuilder facility now instead.

Java Code:

ProcessBuilder builder = new ProcessBuilder("duck.exe");
Process process = builder.start();
int result = process.waitFor();

Where exception handling has been omitted for clarity here.

The process builder allows you to set up input and output streams, to allow your java application to interact with the child process, and allows you to set up the working directory, and environment variables to be present in the child process execution context.

But more immedately, it that Process object has that waitFor() method to allow the calling Java thread to block until the child process completes.