Here you can find the source of isEquals(String str1, String str2)
public static boolean isEquals(String str1, String str2)
//package com.java2s; public class Main { public static boolean isEquals(String str1, String str2) { if (str1 == str2) { return true; }/*from www . j a va2 s . co m*/ if (str1 != null) { return str1.equals(str2); } else { return false; } } }