/* package whatever; // don't place package name! */

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

class Ideone {
	public static void main (String[] args) {
		Map<String, String> characterMap = new HashMap<>();
		characterMap.put("&", "\\x26");
		characterMap.put("^", "\\x5e");
		
		String hello = "Hello& World^"; 
		
		String r = Pattern.compile("\\W").matcher(hello).replaceAll(
		   m -> characterMap.getOrDefault(m.group(), m.group())
		        .replaceAll("\\\\", "$0$0"));
		System.out.println(r);
	}
}