上一篇是StringUtils 链接http://www.cnblogs.com/tele-share/p/8060129.html
1.RandomStringUtils
1.1模拟实现random(count,str);
1 //模拟实现random(5,"helloworld")
2 public static String getRandomString(int count,String str) {
3 if(str != null) {
4 if(!StringUtils.isBlank(str)) {
5 if(count <= 0) {
6 return "";
7 }
8 char[] charArray = str.toCharArray();
9 int index;
10 char[] newArray = new char[count];
11 for(int i=0;i<count;i++) {
12 index = RandomUtils.nextInt(0,charArray.length);
13 newArray[i] = str.charAt(index);
14 }
15 return new String(newArray);
16 }
17 }
18 return null;
19 }
1.2模拟实现randomAlphanumeric(字母与数字混合,可能没有数字)
1 //模拟实现randomAlphanumeric(字母与数字混合)
2 public static String getRandomAlphanumeric(int count) {
3 if(count <=0) {
4 return "";
5 }
6 String letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
7 int number = RandomUtils.nextInt(0,100000);
8 String str = letters + number;
9 return getRandomString(count, str);
10 }
1.3模拟实现可以指定数字个数的randomAlphanumeric
1 //指定数字的个数
2 public static String getRandomAlphanumeric(int count,int numbers) {
3 if(count <=0 || numbers <=0) {
4 return "";
5 }
6 //纯数字
7 if(numbers>=count) {
8 return RandomStringUtils.randomNumeric(numbers);
9 }
10 String letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
11 String str = RandomStringUtils.random(count-numbers, letters) + RandomStringUtils.randomNumeric(numbers);
12 //打乱位置
13 char[] charArray = str.toCharArray();
14 List<Character> list = new ArrayList<Character>();
15 for (Character character : charArray) {
16 list.add(character);
17 }
18 Collections.shuffle(list);
19 for(int i=0;i<list.size();i++) {
20 charArray[i] = list.get(i);
21 }
22 return new String(charArray);
23 }
24
总结:RandomStringUtils中的方法可以用于生成随机的验证字符串
2.RandomUtils
这个类感觉与java.util包下的Random类差别不大,还是那几个类似的方法(注意左闭右开)
相比较来说还是RandomStringUtils用处更多一点