FileWriter fWriter = null;
BufferedWriter writer = null; 
try {
  fWriter = new FileWriter("fileName");
  writer = new BufferedWriter(fWriter);
 
  //WRITES 1 LINE TO FILE AND CHANGES LINE
  writer.write("This line is written");
  writer.newLine();
 
 
   writer.close();
} catch (Exception e) {
 
}

import java.io.*;
/* 
 * Adds 2 integers given by the user, then prints out the sum. 
 */ 
 
 
public class Add2number { 
 
            public static void main(String[] args) throws IOException { 
            BufferedReader stdin = new BufferedReader( 
                  new InputStreamReader(System.in)); 
 
            //asks user for 1st number, then converts it to an integer 
            System.out.print("Enter first integer: "); 
            int x = Integer.parseInt(stdin.readLine()); 
            //asks user for 2nd number, than converts it to an integer 
            System.out.print("Enter second integer: "); 
            int y = Integer.parseInt(stdin.readLine()); 
 
            //add x,y 
            int sum = x + y; 
 
            //Display sum of x,y 
            System.out.println("The sum is: " + sum); 
      }//ends main 
 
}//ends addReadLine

public class Using{
public static void main(String args[]) {
 
 
       try {
Process p = Runtime.getRuntime().exec("java Add2number>C:\\Program Files\\Java\\jdk1.6.0_03\\bin \\out.txt");
} catch(Exception e) {
System.err.println(e);
			System.exit(-1);
} 
 } }

Process p = Runtime.getRuntime().exec("java Add2number>C:\\Program Files\\Java\\jdk1.6.0_03\\bin \\out.txt");

Process p = Runtime.getRuntime().exec("java Add2number>C:\\Program Files\\Java\\jdk1.6.0_03\\bin\\out.txt");