Here you can find the source of createArrayFromUsers(List
public static String createArrayFromUsers(List<String> userList)
//package com.java2s; import java.util.List; public class Main { public static String createArrayFromUsers(List<String> userList) { StringBuilder builder = new StringBuilder(); builder.append(","); for (String user : userList) { builder.append(user);// ww w.j a va2s . c om builder.append(","); } return builder.toString(); } }