package net.javaguides.lang; import java.util.HashMap; import java.util.Map; public class MapNullOrEmptyExample { public static void main(String[] args) { // return true System.out.println(isNullOrEmptyMap(null)); System.out.println(isNullOrEmptyMap(new HashMap < > ())); Map < String, String > map = new HashMap < > (); map.put("key1", "value1"); map.put("key2", "value2"); // return true System.out.println(isNotNullOrEmptyMap(map)); // return false System.out.println(isNullOrEmptyMap(map)); } public static boolean isNullOrEmptyMap(Map << ? , ? > map) { return (map == null || map.isEmpty()); } public static boolean isNotNullOrEmptyMap(Map << ? , ? > map) { return !isNullOrEmptyMap(map); } }