Runtime.exec() - 01

2. The sub process get inputting message from the main process
 
// testSubProcess.java
import java.io.*;
public class testSubProcess{
  public static void main(String[] args){
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("From the main process:"+ br.readLine());
  }
}

//testMainProcess.java
import java.io.*;
public class testMainProcess{
   public static void main(String[] args){
      Runtime rt = Runtime.getRuntime();
      Process p = rt.exec("java testSubProcess");
     //ProcessBuilder pb = new ProcessBuilder("java", "testSubProcess");
     //Process p = pb.start();
      BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
      bw.flush();
      bw.close();
   }
}