Here you can find the source of containsIgnoreCase(Collection
public static boolean containsIgnoreCase(Collection<String> c, String s)
//package com.java2s; //License from project: Apache License import java.util.Collection; public class Main { public static boolean containsIgnoreCase(String[] strArray, String searchStr) { return indexOfIgnoreCase(strArray, searchStr) >= 0; }/*from ww w . ja v a2 s . c o m*/ public static boolean containsIgnoreCase(Collection<String> c, String s) { if (c == null || s == null) { return false; } for (String string : c) { if (string.equalsIgnoreCase(s)) { return true; } } return false; } public static int indexOfIgnoreCase(String[] strArray, String searchStr) { return indexOfString(strArray, searchStr, true); } private static int indexOfString(String[] strArray, String searchStr, boolean ignoreCase) { if ((strArray == null) || (strArray.length == 0)) return -1; boolean found = false; for (int i = 0; i < strArray.length; i++) { if (strArray[i] == null) { if (searchStr == null) found = true; } else { if (ignoreCase) found = strArray[i].equalsIgnoreCase(searchStr); else found = strArray[i].equals(searchStr); } if (found) return i; } return -1; } public static boolean equals(byte[] data1, byte[] data2) { if (data1 == data2) return true; if (data1 == null || data2 == null) return false; if (data1.length != data2.length) return false; for (int i = 0; i < data1.length; i++) { if (data1[i] != data2[i]) return false; } return true; } public static boolean equals(String s0, String s1) { boolean s0Null = s0 == null; boolean s1Null = s1 == null; if (s0Null || s1Null) { return s0Null == s1Null; } return s0.equals(s1); } }