Java tutorial
//package com.java2s; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Main { public static boolean checkCharacter(String character) { boolean flag = false; try { //String check = "[a-zA-Z0-9@.-]{6,20}"; String check = "[1-9][0-9]{5,11}"; Pattern regex = Pattern.compile(check); Matcher matcher = regex.matcher(character); flag = matcher.matches(); } catch (Exception e) { flag = false; } return flag; } }