NumberUtils.java 963 B

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  1. package com.ruoyi.common.utils;
  2. import java.util.Random;
  3. public class NumberUtils {
  4. public static String getRandom(int len) {
  5. int rs = (int) ((Math.random() * 9 + 1) * Math.pow(10, len - 1));
  6. return String.valueOf(rs);
  7. }
  8. public static String getRandom1(int len) {
  9. Random r = new Random();
  10. StringBuilder rs = new StringBuilder();
  11. for (int i = 0; i < len; i++) {
  12. rs.append(r.nextInt(10));
  13. }
  14. return rs.toString();
  15. }
  16. public static boolean isNumeric(String str){
  17. if(StringUtils.isNotEmpty(str)){
  18. str = str.trim();
  19. }
  20. for(int i=str.length();--i>=0;){
  21. int chr=str.charAt(i);
  22. if(chr<48 || chr>57){
  23. return false;
  24. }
  25. }
  26. return true;
  27. }
  28. public static void main(String[] args) {
  29. System.out.println(getRandom1(8));
  30. System.out.println(getRandom(8));
  31. }
  32. }