Check if Map is Null or Empty in Java

In this short article, we will discuss how to check if the Map is empty or null in Java. Let's create a standard utility method to check if the Map is empty or null in Java.

Check if Map is Empty or Null in Java - Utility Methods

1. isNullOrEmptyMap(Map, ?> map) - Return true if the supplied Map is null or empty. Otherwise, return false.
2. isNotNullOrEmptyMap(Map, ?> map) - Return true if the supplied Map is not null or not empty. Otherwise, return false.

1. isNullOrEmptyMap(Map, ?> map)

Return true if the supplied Map is null or empty. Otherwise, return false.

public static boolean isNullOrEmptyMap(Map << ? , ? > map) {
    return (map == null || map.isEmpty());
}

2. isNotNullOrEmptyMap(Map, ?> map)

Return true if the supplied Map is not null or not empty. Otherwise, return false.

public static boolean isNotNullOrEmptyMap(Map << ? , ? > map) {
    return !isNullOrEmptyMap(map);
}

Complete Example

Here is a complete example to test the above utility methods:

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);
    }

}

Output:

true
true
true
false