java string replace using regular expression

/**
 * @author lautturi.com 
 * Java example: java replace string using regexp
 */

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

public class Lautturi {
	public static void main(String[] args) {
		String str = "hello lautturi python world!";
		
		Pattern p = Pattern.compile("python");
		String res = p.matcher(str).replaceAll("java");
		System.out.println(res);
	}
}

output:

hello lautturi java world!