Java join arraylist to string

/**
 * @author lautturi.com 
 * Java example: join elements of arraylist into string
 */

import java.util.*;

public class Lautturi {
	public static void main(String[] args) {
		ArrayList<String> al = new ArrayList<String>();
	      al.add("Hello");
	      al.add("Java");
	      al.add("World");
	      StringBuffer sb = new StringBuffer();
	      
	      for (String s : al) {
	         sb.append(s);
	         sb.append(" ");
	      }
	      String str = sb.toString();
	      System.out.println(str);
	}
}

output:

Hello Java World