Random类，是数学中的随机类，在产生实例时，可以通过无参构造器，以及有参构造器来进行产生，但是2者之间是有区别的
    区别在于：有参构造器产生的实例，随机数是可以复盘的。

    1. public static void main(String[] args) {
    2.         // TODO Auto-generated method stub
    3.         Random random = new Random();
    4.         //产生一定范围的随机值，比如0-5之间的数据
    5.         System.out.println(random.nextInt(5) + 1);
    6.         // 产生随机数
    7.         System.out.println(random.nextInt());
    8.         System.out.println(random.nextInt());
    9.         System.out.println(random.nextInt());
    10.         System.out.println(random.nextInt());
    11.         System.out.println(random.nextDouble());
    12.         System.out.println(random.nextDouble());
    13.         System.out.println(random.nextBoolean());
    14.         System.out.println(random.nextBoolean());
    15.         System.out.println(random.nextBoolean());
    16.         System.out.println("-----------------------");
    17.         Random random04 = new Random();
    18.         // 产生随机数
    19.         System.out.println(random04.nextInt());
    20.         System.out.println(random04.nextInt());
    21.         System.out.println(random04.nextInt());
    22.         System.out.println(random04.nextInt());
    23.         System.out.println(random04.nextDouble());
    24.         System.out.println(random04.nextDouble());
    25.         System.out.println(random04.nextBoolean());
    26.         System.out.println(random04.nextBoolean());
    27.         System.out.println(random04.nextBoolean());
    28. //        Random random02 = new Random(10000);
    29. //
    30. //        // 产生随机数
    31. //        System.out.println(random02.nextInt());
    32. //        System.out.println(random02.nextInt());
    33. //        System.out.println(random02.nextInt());
    34. //        System.out.println(random02.nextInt());
    35. //
    36. //        System.out.println(random02.nextDouble());
    37. //        System.out.println(random02.nextDouble());
    38. //
    39. //        System.out.println(random02.nextBoolean());
    40. //        System.out.println(random02.nextBoolean());
    41. //        System.out.println(random02.nextBoolean());
    42. //
    43. //        System.out.println("--------------------");
    44. //        Random random03 = new Random(10000);
    45. //
    46. //        // 产生随机数
    47. //        System.out.println(random03.nextInt());
    48. //        System.out.println(random03.nextInt());
    49. //        System.out.println(random03.nextInt());
    50. //        System.out.println(random03.nextInt());
    51. //
    52. //        System.out.println(random03.nextDouble());
    53. //        System.out.println(random03.nextDouble());
    54. //
    55. //        System.out.println(random03.nextBoolean());
    56. //        System.out.println(random03.nextBoolean());
    57. //        System.out.println(random03.nextBoolean());
    58. //        
    59.     }

    Random（seed）中，seed是int类型的参数，相同的seed，随机出来的结果也相同