The method Map.getOrDefault(key, defaultValue) returns mapped value for the given key or defaultValue if there is no such mapping.

The signature of the java.util.Map.getOrDefault(key, defaultValue) method is as follows:

default V getOrDefault(Object key,
                       V defaultValue)

The method is available since Java 8.

• Object key: the key whose associated value is to be returned
• V defaultValue: the default mapping of the key

Returns the value for given key or defaultValue if there is no mapping for the given key.

• ClassCastException: if the key is of an inappropriate type for this map (optional)
• NullPointerException: if the specified key is null and this map does not permit null keys (optional)

In the following code we use java.util.Map.getOrDefault(key, defaultValue) to simplify getting values from a map:

package com.farenda.java.util;

import java.util.HashMap;
import java.util.Map;

public class MapExamples {

    public static void main(String[] args) {
        Map<Integer,String> vilians = new HashMap<>();
        vilians.put(1, "Kajko");
        System.out.println("Original map: " + vilians);

        // pre Java 8 version:
        String name;
        if (vilians.containsKey(2)) {
            name = vilians.get(2);
        } else {
            name = "Kokosz";
        }
        System.out.println("Name: " + name);

        // Java 8 version:
        name = vilians.getOrDefault(2, "Kokosz");
        System.out.println("Name: " + name);
    }
}

The above code produces the following output:

Original map: {1=Kajko}
Name: Kokosz
Name: Kokosz

• Java 8 Map API