1、Message.java
public class Message {

 public static void main(String[] args) {
    if (args[0].equals("-h"))
          System.out.print("Hello,");
       else if (args[0].equals("-g"))
          System.out.print("Goodbye,");
       // print the other command line arguments
       for (int i = 1; i < args.length; i++)
          System.out.print(" " + args[i]);
       System.out.println("!");

 }
}

test:
java Message -g cruel world



import java.util.*;
import javax.swing.*;
public class FirstSample {

 public static void main(String[] args) {
       String input = JOptionPane.showInputDialog
          ("How many numbers do you need to draw?");
       int k = Integer.parseInt(input);

       input = JOptionPane.showInputDialog
          ("What is the highest number you can draw?");
       int n = Integer.parseInt(input);

       // fill an array with numbers 1 2 3 . . . n
       int[] numbers = new int[n];
       for (int i = 0; i < numbers.length; i++)
       {    numbers[i] = i + 1;
       System.out.println(numbers[i]);
       }
       // draw k numbers and put them into a second array

       int[] result = new int[k];
       for (int i = 0; i < result.length; i++)
       { 
          // make a random index between 0 and n - 1
          int r = (int)(Math.random() * n);

          // pick the element at the random location
          result[i] = numbers[r];

          // move the last element into the random location
          numbers[r] = numbers[n - 1];
          n--;
       }

       // print the sorted array

       Arrays.sort(result);
       System.out.println
          ("Bet the following combination. It'll make you rich!");
       for (int i = 0; i < result.length; i++)
          System.out.println(result[i]);

       System.exit(0);

 }
}