Java 获得随机一段字符串

Java获得随机的一定长度的一段字符串方法：

Code：

import java.util.Random;public class Demo {public static void main(String args[]){Demo demo = new Demo();System.out.println(demo.getRandomString(20));}public static String getRandomString(int length) {     StringBuffer buffer = new StringBuffer("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");     StringBuffer sb = new StringBuffer();     Random random = new Random();     int range = buffer.length();     for (int i = 0; i < length; i ++) {         sb.append(buffer.charAt(random.nextInt(range)));     }     return sb.toString(); }}

代码解读：

调用getRandomString（）方法时的length参数为要返回的随机字符串的长度。

StringBuffer buffer = new StringBuffer("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");

0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

此段字符串代表要出现的字符还可以是其他字符

如：- +  = * 。.等等