Java regular expressions match the telephone format

As you all know, a regular expression is a specification that can be used for pattern matching and substitution. A regular expression is a literal pattern composed of ordinary characters (such as characters a through z) and special characters (metacharacters) to describe one or more strings to be matched when looking for a literal body. A regular expression ACTS as a template to match a character pattern to the string being searched for.

  private boolean telCheck(String tel){
    Pattern p = Pattern.compile("^((13\d{9}$)|(15[0,1,2,3,5,6,7,8,9]\d{8}$)|(18[0,2,5,6,7,8,9]\d{8}$)|(147\d{8})$)");
    Matcher m = p.matcher(tel);
    return m.matches();
  }

Java regular expression validation format (mailbox, phone number)

package com.firewolf.utils;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegexValidateUtil {
  public static void main(String[] args) {
    System.out.println(checkEmail("14_8@qw.df"));
    System.out.println(checkMobileNumber("071-3534452"));
  }
  
  public static boolean checkEmail(String email){
    boolean flag = false;
    try{
        String check = "^([a-z0-9A-Z]+[-|_|\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\.)+[a-zA-Z]{2,}$";
        Pattern regex = Pattern.compile(check);
        Matcher matcher = regex.matcher(email);
        flag = matcher.matches();
      }catch(Exception e){
        flag = false;
      }
    return flag;
  }
  
  public static boolean checkMobileNumber(String mobileNumber){
    boolean flag = false;
    try{
        Pattern regex = Pattern.compile("^(((13[0-9])|(15([0-3]|[5-9]))|(18[0,5-9]))\d{8})|(0\d{2}-\d{8})|(0\d{3}-\d{7})$");
        Matcher matcher = regex.matcher(mobileNumber);
        flag = matcher.matches();
      }catch(Exception e){
        flag = false;
      }
    return flag;
  }
}