package com.ycl.common.util;

import java.util.Random;

public class RandomStringUtil {
	public static final String NUMBERS = "0123456789";
	public static final String LOWER_CASE = "abcdefghijklmnopqrstuvwxyz";
	public static final String CAPITAL = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	public static final String CAPITAL_NUM = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	public static final String CAPITAL_NUM_LOWER = "0123456789abcdefghijklmnopqrstuvwxyz";
	public static final String ALL = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";


	
	/**
	 * 生成指定长度的随机字符串
	 * 
	 * @param length
	 * @return
	 */
	public static String getRandomString(int length, String base) { // length表示生成字符串的长度
		int baseLength = base.length();
		Random random = new Random();
		StringBuffer sb = new StringBuffer("");
		for (int i = 0; i < length; i++) {
			int number = random.nextInt(baseLength);
			sb.append(base.charAt(number));
		}
		return sb.toString();
	}
	
	public static void main(String[] args) {
		System.out.println(getRandomString(6, RandomStringUtil.NUMBERS));
	}
}