1.可以产生10000000 和 99999999之间随机数
2.可以产生规定数字之间的随机数,如25 100之间
3.可以使用algorithm 和 provider产生一个SecureRandom随机数字或字符串
object instead of a Random object: 71
4.可以产生浮点浮点随机数;
5.可以产生a-zA-Z0-9之间的规定长度个字符串
6.可以产生规定长度的小写字母字符串
7.可以产生任意字符串.
以下jsp bean 在Tomcat Win2000 下调试通过:
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随机字符串bean
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package mycollect;
2
3import java.util.*;
4import java.security.SecureRandom;
5import java.security.NoSuchAlgorithmException;
6import java.security.NoSuchProviderException;
7
8![]()
JSP调用语句:2
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1<%@ page contentType="text/html;charset=ISO8859_1" %>
2<%@ page import="java.util.*" %>
3<jsp:useBean id="RNUM" scope="page" class="mycollect.RandomNum" />
4<jsp:useBean id="RSTR" scope="page" class="mycollect.RandomStrg" />
5
6<html>
7<head>
8<title>随机数字 浮点数 字符串</title>
9<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
10</head>
11
12<body>
13<h3>随机数字 浮点数 字符串</h3>
14<%
15//Random generator = new Random();
16//int limit = 10;
17//int randomNumber = (int)(generator.nextDouble() * limit);
18
19
20out.println("<p>创建在10000000 和 99999999之间的随机数:");
21RNUM.setRange("10000000-99999999");
22RNUM.generateRandomObject();
23out.println("<b>"+RNUM.getRandom().intValue()+"</b>");
24
25out.println("<p>在n 25 和 100之间创建一个随机数:");
26RNUM.setRange("25-100");
27RNUM.generateRandomObject();
28out.println("<b>"+RNUM.getRandom().intValue()+"</b>");
29
30%>
31<p>Create the same random number between 25 and 100, only use the <br>
32algorithm and provider attributes to indicate the use of a SecureRandom<br>
33object instead of a Random object:
34<%
35RNUM.setRange("25-100");
36RNUM.setAlgorithm("SHA1PRNG");
37RNUM.setProvider("SUN");
38RNUM.generateRandomObject();
39out.println("<b>"+RNUM.getRandom().intValue()+"</b>");
40
41out.println("<p>Create a random float value:");
42RNUM.setRange("0-1");
43RNUM.generateRandomObject();
44String radio= new java.text.DecimalFormat("###.##########").format(RNUM.getRandom());
45out.println("<b>"+radio+"</b>");
46
47out.println("<p>===========================================");
48
49out.println("<p>在a-zA-Z0-9之间,也就是数字和26个字母混合的随机字符串,(欠缺是8位,该功能适合创建随机密码和sessionid)");
50RSTR.setCharset("a-zA-Z0-9");
51RSTR.generateRandomObject();
52out.println("<b>"+RSTR.getRandom()+"</b>");
53
54
55out.println("<p>Create a random string 15 lowercase letters long:");
56RSTR.setCharset("a-z");
57RSTR.setLength("15");
58RSTR.generateRandomObject();
59out.println("<b>"+RSTR.getRandom()+"</b>");
60
61out.println("<p>Create a random string with only caps:");
62RSTR.setCharset("A-Z");
63RSTR.generateRandomObject();
64out.println("<b>"+RSTR.getRandom()+"</b>");
65
66out.println("<p>Create a random string 10 characters long with the charset a-fF-K ! \\ $ % # ^ - * ? notice that the - and had to be escaped with a :");
67RSTR.setCharset("a-fF-K!\\$%#^-*?");
68RSTR.setLength("10");
69RSTR.generateRandomObject();
70out.println("<b>"+RSTR.getRandom()+"</b>");
71
72
73out.println("<p>Create a random string of all the characters and digits:");
74RSTR.setCharset("all");
75RSTR.generateRandomObject();
76out.println("<b>"+RSTR.getRandom()+" </b>");
77
78%><p>
79Create the same random string of all the characters and digits, only use<br>
80the algorithm and provider attributes to indicate the use of a SecureRandom<br>
81object instead of a Random object:
82<%
83RSTR.setCharset("all");
84RSTR.setAlgorithm("SHA1PRNG");
85RSTR.setProvider("SUN");
86RSTR.generateRandomObject();
87out.println("<b>"+RSTR.getRandom()+"</b>");
88
89%>
90
91</body>
92</html>
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