java remove non numeric characters from string

/**
 * @author lautturi.com 
 * Java example: remove all non digit characters in java string
 */

import java.util.*;

public class Lautturi {

	public static void main(String[] args) {

		String str = "hello 123 world 1auttur12456 ";
		str = str.replaceAll("\\D", "");
		System.out.println(str);
	}
}

output:

123112456