Execute a command prompt command and view output in Java

Execute a command prompt command & view output in Java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class RuntimeExec {
 public StreamWrapper getStreamWrapper(InputStream is, String type) {
  return new StreamWrapper(is, type);
 }

 private class StreamWrapper extends Thread {
  InputStream is = null;
  String type = null;
  String message = null;

  public String getMessage() {
   return message;
  }

  StreamWrapper(InputStream is, String type) {
   this.is = is;
   this.type = type;
  }

  public void run() {
   try {
    BufferedReader br = new BufferedReader(
      new InputStreamReader(is));
    StringBuffer buffer = new StringBuffer();
    String line = null;
    while ((line = br.readLine()) != null) {
     buffer.append(line);// .append("\n");
    }
    message = buffer.toString();
   } catch (IOException ioe) {
    ioe.printStackTrace();
   }
  }
 }

 // this is where the action is
 public static void main(String[] args) {
  System.out.println("--Process started--");
  Runtime rt = Runtime.getRuntime();
  RuntimeExec rte = new RuntimeExec();
  StreamWrapper error, output;

  try {
   Process proc = rt.exec("ping localhost");
   error = rte.getStreamWrapper(proc.getErrorStream(), "ERROR");
   output = rte.getStreamWrapper(proc.getInputStream(), "OUTPUT");
   int exitVal = 0;

   error.start();
   output.start();
   error.join(3000);
   output.join(3000);
   exitVal = proc.waitFor();
   System.out.println("Output: " + output.message + "\nError: "
     + error.message);
   System.out.println("--Process ended--");
  } catch (IOException e) {
   e.printStackTrace();
  } catch (InterruptedException e) {
   e.printStackTrace();
  }
 }
}