Here you can find the source of isCollectionType(Object obj)
public static boolean isCollectionType(Object obj)
//package com.java2s; //License from project: Apache License import java.util.*; public class Main { public static boolean isCollectionType(Object obj) { return (obj.getClass().isArray() || (obj instanceof Collection) || (obj instanceof Hashtable) || (obj instanceof HashMap) || (obj instanceof HashSet) || (obj instanceof List) || (obj instanceof AbstractMap)); }// w ww.j a v a 2s.c o m }