cn.junit.util.RandomUtil 本人测试用的工具类

package cn.junit.util; import java.util.Random; public class RandomUtil { private static final String allChar = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; private static final String letterChar = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; private static final String digitChar = "0123456789"; /** * 返回一个定长的随机字符串 (只包含数字) * @param length * 随机字符串长度 * @return 随机字符串 */ public static String generateDigitString(int length){ StringBuilder sb = new StringBuilder(); Random random = new Random(); for(int i=0;i<length;i++){ sb.append(digitChar.charAt(random.nextInt(digitChar.length()))); } return sb.toString(); } /** * 生成一个位于最小值与最大值之间的整数 * @param min * 最小值 * @param max * 最大值 * @return * 数 */ public static int generateIntBetweenMinMax(int min,int max){ Random random = new Random(); if(min > max){ int tmp = 0; tmp = min; min = max; max = tmp; } return random.nextInt(max - min) + min; } /** * 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) { StringBuilder sb = new StringBuilder(); Random random = new Random(); for (int i = 0; i < length; i++) { sb.append(allChar.charAt(random.nextInt(allChar.length()))); } return sb.toString(); } /** * 生成一个位于两数值之间的随机长度字符串 * @param minLen 最小长度值 * @param maxLen 最大长度值 * @return 字符串 */ public static String generateString(int minLen,int maxLen){ Random random = new Random(); if(minLen > maxLen){ int tmp = 0; tmp = minLen; minLen = maxLen; maxLen = tmp; } return generateString(random.nextInt(maxLen - minLen) + minLen); } /** * 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) { StringBuilder sb = new StringBuilder(); 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小写字母字符串(只包含小写字母) * * @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大写字母字符串(只包含大写字母) * * @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) { StringBuilder sb = new StringBuilder(); 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) { StringBuilder sb = new StringBuilder(); 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(); } /** * 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(int num, int fixdlenth) { StringBuilder sb = new StringBuilder(); 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(); } public static void main(String[] args) { System.out.println(generateString(15)); System.out.println(generateMixString(15)); System.out.println(generateLowerString(15)); System.out.println(generateUpperString(15)); System.out.println(generateZeroString(15)); System.out.println(toFixdLengthString(123, 15)); System.out.println(toFixdLengthString(123L, 15)); } }