java随机字符串生成示例

package com.phyl.password;

import java.util.arraylist;
import java.util.arrays;
import java.util.random;
/**
 * 字符随机生成类
 * @author asus
 *
 */
public class password {

 /**
  * 密码类型枚举
  * @author asus
  */
 public static enum type {
  /**
   * 字符型
   */
  letter,
  /**
   * 大写字符型
   */
  capital,
  /**
   * 数字型
   */
  number,
  /**
   * 符号型
   */
  sign,
  /**
   * 大+小字符 型
   */
  letter_capital,
  /**
   * 小字符+数字 型
   */
  letter_number,
  /**
   * 大+小字符+数字 型
   */
  letter_capital_number,
  /**
   * 大+小字符+数字+符号 型
   */
  letter_capital_number_sign
 }

 private static string[] lowercase = {
   "a","b","c","d","e","f","g","h","i","j","k",
   "l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};

 private static string[] capital = {
   "a","b","c","d","e","f","g","h","i","j","k",
   "l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"}; 

 private static string[] number = {
   "1","2","3","4","5","6","7","8","9","0"};

 private static string[] sign = {
   "~","!","@","#","$","%","^","&","*","(",")","_","+","`","-","=",
   "{","}","|",":","\"","<",">","?",
   "[","]","\\",";","'",",",".","/"};

 /**
  * 静态随机数
  */
 private static random random = new random();

 public static void main(string[] args) {
  system.out.println(password.getrandom(24, password.type.capital));
 }

 /**
  * 获取随机组合码
  * @param num 位数
  * @param type 类型
  * @type
  * <br>字符型 letter,
  * <br>大写字符型 capital,
  * <br>数字型 number,
  * <br>符号型 sign,
  * <br>大+小字符 型 letter_capital,
  * <br>小字符+数字 型 letter_number,
  * <br>大+小字符+数字 型 letter_capital_number,
  * <br>大+小字符+数字+符号 型 letter_capital_number_sign
  */
 public static string getrandom(int num,type type){
  arraylist<string> temp = new arraylist<string>();
  stringbuffer code = new stringbuffer();
  if(type == type.letter){
   temp.addall(arrays.aslist(lowercase));
  }else if(type == type.capital){
   temp.addall(arrays.aslist(capital));
  }else if(type == type.number){
   temp.addall(arrays.aslist(number));
  }else if(type == type.sign){
   temp.addall(arrays.aslist(sign));
  }else if(type == type.letter_capital){
   temp.addall(arrays.aslist(lowercase));
   temp.addall(arrays.aslist(capital));
  }else if(type == type.letter_number){
   temp.addall(arrays.aslist(lowercase));
   temp.addall(arrays.aslist(number));
  }else if(type == type.letter_capital_number){
   temp.addall(arrays.aslist(lowercase));
   temp.addall(arrays.aslist(capital));
   temp.addall(arrays.aslist(number));
  }else if(type == type.letter_capital_number_sign){
   temp.addall(arrays.aslist(lowercase));
   temp.addall(arrays.aslist(capital));
   temp.addall(arrays.aslist(number));
   temp.addall(arrays.aslist(sign));
  }
  for (int i = 0; i < num; i++) {
   code.append(temp.get(random.nextint(temp.size())));
  }
  return code.tostring();
 }

}