Java生成随机字符串的代码

public static String getRandomString(int length) { //length表示生成字符串的长度
     String base = "abcdefghijklmnopqrstuvwxyz0123456789";  
     Random random = new Random();  
     StringBuffer sb = new StringBuffer();  
     for (int i = 0; i < length; i++) {  
         int number = random.nextInt(base.length());  
         sb.append(base.charAt(number));  
     }  
     return sb.toString();  
  }