Java: sample code to run system command from servlet

package my.application.helloWorld;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class HelloWorldServlet
 */
@WebServlet("/HelloWorldServlet")
public class HelloWorldServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public HelloWorldServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // response.getOutputStream().println("Hello World at " + (new
        // Date()).toString());

        try {
            Runtime rt = Runtime.getRuntime();

            Process pr = rt.exec("ls");

            BufferedReader input = new BufferedReader(new InputStreamReader(
                    pr.getInputStream()));

            String line = null;
            response.getOutputStream().println("Hellow World!");

            while ((line = input.readLine()) != null) {
                response.getOutputStream().println(line);

            }

            int exitVal = pr.waitFor();
            response.getOutputStream().println("This is Exited with error code " + exitVal);

        } catch (Exception e) {
            response.getOutputStream().println(e.toString());
            e.printStackTrace();
        }
    }

    public static void executeShellCommand( String command ) throws InterruptedException, IOException {
        Runtime.getRuntime().exec( command.split( " " ) ).waitFor();
      }
   
    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}