java regex to validate phone number

java regex regular expression validate 10 digit number

/**
 * @author lautturi.com 
 * Java example: java match 10 digit number in regex 
 */

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Lautturi {
	public static void main(String[] args) {

		String str = "1234567890";
		String regex = "^\\d{10}$";
		Pattern pattern = Pattern.compile(regex);
		Matcher matcher = pattern.matcher(str);
		Boolean b = matcher.matches();

		System.out.println(b);
	}
}

output:

true