Here you can find the source of convertString(Collection
public static String convertString(Collection<String> strings)
//package com.java2s; /**/*from www .ja v a 2 s .co m*/ * The contents of this file are subject to the OpenMRS Public License * Version 1.0 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://license.openmrs.org * * Software distributed under the License is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the * License for the specific language governing rights and limitations * under the License. * * Copyright (C) OpenMRS, LLC. All Rights Reserved. */ import java.util.*; public class Main { public static String convertString(Collection<String> strings) { StringBuilder builder = new StringBuilder(); for (String string : strings) builder.append(string).append(","); return builder.toString(); } }