Rondom的用法

package com.designer;

import java.util.Random;

public class TestRandom
{
   public  static String source = "abcdefghijklmnopqrskuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    
    //獲得指定長度的隨機字符串  
    public  String getRandString(int maxLength)
    {
        StringBuffer sb = new StringBuffer();
        Random rand = new Random();
        for (int i = 0; i < maxLength; i++)
        {
            //返回rand.nextInt(source.length()))這個範圍內的隨機數
            sb.append(source.charAt(rand.nextInt(source.length())));
        }
        return sb.toString();
    }
    
    public static void main(String[] args)
    {
        TestRandom trn = new TestRandom();
//        System.out.println(trn.getRandString(5));
        System.out.println(trn.getRandString(5));
        //靜態方法裏面  不能訪問非靜態的成員（靜態成員優先於對象加載）
       
        StringBuffer sb = new StringBuffer();
        Random rand1 = new Random();
        print(source.charAt(0));
        int i=3;
        while(i<10)
        {
         print(rand1.nextInt(3)); //0 1 2 (3以內的隨機數，但是不包括3)
         i++;
        }
//        sb.append(source.charAt(rand.nextInt(source.length())));
    }
    
    public static void print(Object abc)
    {
        System.out.println(abc);
    }
    
}