Java随机生成N位数字验证码
package monserver.utils;import java.util.Random;public class GenerateRandomNumber {public static String generate(int n) {//定义取值范围String str = "0123456789";//容量为4StringBuilder sb = new StringBuilder(n);for (int i = 0; i < n; i++) {//遍历4次，拿到某个字符并且拼接char ch = str.charAt(new Random().nextInt(str.length()));sb.append(ch);}return sb.toString();}public static String generateFour() {return generate(4);}public static void main(String[] args) {System.out.println(generate(10));System.out.println(generateFour());}}
知是行之始，行是知之成
