Here you can find the source of convertListToString(List
public static String convertListToString(List<String> strList)
//package com.java2s; // are made available under the terms of the Eclipse Public License v1.0 import java.util.List; public class Main { public static final String COMMA_SEPARATOR = ","; public static String convertListToString(List<String> strList) { String string = ""; //$NON-NLS-1$ int i = 0; if (strList != null) { for (String aString : strList) { if (i++ > 0) string = string.concat(COMMA_SEPARATOR); string = string.concat(aString); }/*from w w w . ja v a 2 s . c om*/ } return string; } }