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package com.jm.util;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.util.ArrayList;import java.util.List;import java.util.Random;import Decoder.BASE64Encoder;import com.jm.bean.JmAward;public class RandomUtil {	/**	 * 获取从a至z，长度为length随机数	 * @return	 */	public static String getRandomStr(int length){		String base="abcdefghijklmnopqrstuvwxyz";		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();   	}	/**	 * 获取范围内int值	 * @param 获取范围内int值	 * @return	 */	public static int getRandomRange(int max,int min){		return (int)(Math.random()*(max-min)+min);	}	/**	 * 获取随机长度随机字符	 * @param length base	 * @return	 */	public static String getRandomString(int length,String base) { //length表示生成字符串的长度	    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();   	 }  	/**	 * 获取随机长度随机字符	 * @param length	 * @return	 */	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();   	 }  	/**	 * 获取随机长度随机数字	 * @param length	 * @return	 */	public static String getRandomNumString(int length) { //length表示生成字符串的长度	    String base = "0123456789";   	    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();   	 }  	/**	 * 返回随机数组	 * @param start 开始值	 * @param end  结束值	 * @return	 */	public static int[] getRangRandom(int start, int end) {		return getRangRandom(start, end, end - start + 1);	}		/**	 * 返回指定范围指定个数的不重复随机数。	 * @param start	 * @param end	 * @param num	 * @return	 */	public static int[] getRangRandom(int start, int end, int num) {				int length = end - start + 1;		//参数不合法		if (length < 1 || num > length) {			return null;		}		else {						int[] numbers = new int[length];			int[] result = new int[num];						//循环赋初始值			for (int i = 0; i < length; i ++) {				numbers[i] = i + start;			}						Random random = new Random();						//取randomMax次数			for (int i = 0; i < num; i ++) {								//随机获取取数的位置				int m = random.nextInt(length - i) + i;								result[i] = numbers[m];								//交换位置				int temp = numbers[m];				numbers[m] = numbers[i];				numbers[i] = temp;			}						return result;		}			}		}

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