Here you can find the source of convertStringCollectionToString(Collection
public static String convertStringCollectionToString(Collection<String> value, String separator)
//package com.java2s; //License from project: Open Source License import java.util.Collection; public class Main { public static String convertStringCollectionToString(Collection<String> value, String separator) { if (value.size() == 0) { return ""; }/*w w w. j av a 2 s .c om*/ StringBuilder sb = new StringBuilder(); for (String v : value) { sb.append(v); sb.append(separator); } sb.setLength(sb.length() - separator.length()); return sb.toString(); } }