Invoking external program from Java

To invoke the external programs from Java, the simplest way is to use the capabilities of the Runtime class. Following sample program should illustrate the same:

 import java.io.*;  
 public class Main {  
   public static void main(String args[]) {  
    try {  
    Runtime rt = Runtime.getRuntime();  
    //Process pr = rt.exec("cmd /c dir");  
    Process pr = rt.exec("c:\\helloworld.exe");  
    BufferedReader input = new BufferedReader(new   
     InputStreamReader(pr.getInputStream()));  
    String line=null;  
    while((line=input.readLine()) != null) {  
     System.out.println(line);  
    }  
    int exitVal = pr.waitFor();  
    System.out.println("Exited with error code "+exitVal);  
    } catch(Exception e) {  
     System.out.println(e.toString());  
     e.printStackTrace();  
    }  
   }  

While hunting for this solution, I came across a very elaborate link regarding the same.
http://www.rgagnon.com/javadetails/java-0014.html