java判断ipv4

package exam1;

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

public class Main{
	public static void match(String regex, String sourceText){
		  Pattern pattern = Pattern.compile(regex);
		  Matcher matcher = pattern.matcher(sourceText);
		  if(matcher.find()){
		    System.out.println("true");
		  }else{
			  System.out.println("false");
		  }
		  
		}
		public static void main(String[] args) {
		  String regex = "^(((\\d{1,2})|(1\\d{2})|(2[0-4]\\d)|(25[0-5]))\\.){3}((\\d{1,2})|(1\\d{2})|(2[0-4]\\d)|(25[0-5]))$";
		  Scanner in = new Scanner(System.in);
		  String x = in.next();
		  match(regex, x);
		}
}