生成指定长度带数字和字母的

来源：互联网发布：淘宝免费模板代码编辑：程序博客网时间：2024/04/29 15:07
package com.test.util;import java.util.Random;public class RandomUtil {private static final String ALLCHAR = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";private static final String LETTERCHAR = "abcdefghijkllmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";private static final String NUMBERCHAR = "0123456789";/** * 返回一个定长的随机字符串(只包含大小写字母、数字) *  * @param length *            随机字符串长度 * @return 随机字符串 */public static String generateString(int length) {StringBuffer sb = new StringBuffer();Random random = new Random();for (int i = 0; i < length; i++) {sb.append(ALLCHAR.charAt(random.nextInt(ALLCHAR.length())));}return sb.toString();}/** * 返回一个定长的随机纯字母字符串(只包含大小写字母) *  * @param length *            随机字符串长度 * @return 随机字符串 */public static String generateMixString(int length) {StringBuffer sb = new StringBuffer();Random random = new Random();for (int i = 0; i < length; i++) {sb.append(ALLCHAR.charAt(random.nextInt(LETTERCHAR.length())));}return sb.toString();}/** * 返回一个定长的随机纯大写字母字符串(只包含大小写字母) *  * @param length *            随机字符串长度 * @return 随机字符串 */public static String generateLowerString(int length) {return generateMixString(length).toLowerCase();}/** * 返回一个定长的随机纯小写字母字符串(只包含大小写字母) *  * @param length *            随机字符串长度 * @return 随机字符串 */public static String generateUpperString(int length) {return generateMixString(length).toUpperCase();}/** * 生成一个定长的纯0字符串 *  * @param length *            字符串长度 * @return 纯0字符串 */public static String generateZeroString(int length) {StringBuffer sb = new StringBuffer();for (int i = 0; i < length; i++) {sb.append('0');}return sb.toString();}/** * 根据数字生成一个定长的字符串，长度不够前面补0 *  * @param num *            数字 * @param fixdlenth *            字符串长度 * @return 定长的字符串 */public static String toFixdLengthString(long num, int fixdlenth) {StringBuffer sb = new StringBuffer();String strNum = String.valueOf(num);if (fixdlenth - strNum.length() >= 0) {sb.append(generateZeroString(fixdlenth - strNum.length()));} else {throw new RuntimeException("将数字" + num + "转化为长度为" + fixdlenth+ "的字符串发生异常！");}sb.append(strNum);return sb.toString();}/** * 每次生成的len位数都不相同 *  * @param param * @return 定长的数字 */public static int getNotSimple(int[] param, int len) {Random rand = new Random();for (int i = param.length; i > 1; i--) {int index = rand.nextInt(i);int tmp = param[index];param[index] = param[i - 1];param[i - 1] = tmp;}int result = 0;for (int i = 0; i < len; i++) {result = result * 10 + param[i];}return result;}public static void main(String[] args) {System.out.println("返回一个定长的随机字符串(只包含大小写字母、数字):" + generateString(20));System.out.println("返回一个定长的随机纯字母字符串(只包含大小写字母):" + generateMixString(10));System.out.println("返回一个定长的随机纯大写字母字符串(只包含大小写字母):"+ generateLowerString(10));System.out.println("返回一个定长的随机纯小写字母字符串(只包含大小写字母):"+ generateUpperString(10));System.out.println("生成一个定长的纯0字符串:" + generateZeroString(10));System.out.println("根据数字生成一个定长的字符串，长度不够前面补0:"+ toFixdLengthString(123, 10));int[] in = { 1, 2, 3, 4, 5, 6, 7 };System.out.println("每次生成的len位数都不相同:" + getNotSimple(in, 3));}}
0 0