Here you can find the source of isEmpty(final Collection values)
public static boolean isEmpty(final Collection values)
//package com.java2s; //License from project: Apache License import java.util.Collection; import java.util.Map; public class Main { public static boolean isEmpty(final String value) { if (value == null) { return true; } else {//from w w w.j a va2 s. c o m return value.trim().isEmpty(); } } public static boolean isEmpty(final Collection values) { return (values == null) || values.isEmpty(); } public static boolean isEmpty(final Map values) { return (values == null) || values.isEmpty(); } }