Here you can find the source of containsIgnoreCase4Collections(Collection
public static boolean containsIgnoreCase4Collections(Collection<String> c, String s)
//package com.java2s; //License from project: Apache License import java.util.Collection; public class Main { public static boolean containsIgnoreCase4Collections(Collection<String> c, String s) { if (c == null || s == null) { return false; }// w ww . java 2 s . c o m for (String string : c) { if (string.equalsIgnoreCase(s)) { return true; } } return false; } }