Java随机数

 1 　　@Test
 2     public void test1(){
 3         Random rd=new Random();
 4         System.out.println(rd.nextInt());      //2110276222
 5         System.out.println(rd.nextInt(10));    //5
 6         System.out.println(rd.nextFloat());    //0.92339724
 7         System.out.println(rd.nextDouble());   //0.12333168823610974
 8         System.out.println(rd.nextLong());     //-993158337391878589
 9         System.out.println(rd.nextBoolean());  //true
10     }

 1 　　@Test
 2     public void test2(){
 3         Random rd=new Random();
 4         int max=50;
 5         int min=20;
 6         for (int i = 0; i < 20; i++) {
 7             int j=rd.nextInt(max-min+1)+min;
 8             System.out.println(j);
 9         }
10     }