simple root using code

Process p; 

try { 

   // Preform su to get root privledges

   p = Runtime.getRuntime().exec("su"); 

   

   // Attempt to write a file to a root-only 

   DataOutputStream os = new DataOutputStream(p.getOutputStream()); 

   os.writeBytes("echo \"Do I have root?\" >/system/sd/temporary.txt\n");

   

   // Close the terminal

   os.writeBytes("exit\n"); 

   os.flush(); 

   try { 

      p.waitFor(); 

           if (p.exitValue() != 255) { 

           // TODO Code to run on success

              toastMessage("root");

           } 

           else { 

            // TODO Code to run on unsuccessful

            toastMessage("not root");    

           } 

   } catch (InterruptedException e) { 

      // TODO Code to run in interrupted exception

    toastMessage("not root"); 

   } 

} catch (IOException e) { 

   // TODO Code to run in input/output exception

 toastMessage("not root"); 

}








source : http://www.stealthcopter.com/blog/2010/01/android-requesting-root-access-in-your-app/