Package dev.bannmann.labs.core

Class MapExtras

java.lang.Object

dev.bannmann.labs.core.MapExtras

public final class MapExtras
extends Object

Method Summary

Modifier and Type	Method	Description
static <K extends @Nullable Object, V extends @Nullable Object> @NonNull V	obtain(Map<K,V> map, K key)	Gets the value to which the given key is mapped or throws an exception.
static <K extends @Nullable Object, V extends @Nullable Object> Optional<@NonNull V>	tryGet(Map<K,V> map, K key)	Gets the value to which the given key is mapped, if existing.
static <K extends @Nullable Object, V extends @Nullable Object> Optional<@NonNull V>	tryRemove(Map<K,V> map, K key)	Removes a mapping for the given key, if one exists.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

tryGet

public static <K extends @Nullable Object,
V extends @Nullable Object>
Optional<@NonNull V> tryGet(Map<K,V> map,
 K key)

Gets the value to which the given key is mapped, if existing.

Unlike Map.get(Object), with this method the compiler verifies the type of the key argument. Also, as it returns an Optional, calling code can use chained method calls instead of separate if blocks.

Returns:

a present Optional if the given map contains a non-null value for the given key.

tryRemove

public static <K extends @Nullable Object,
V extends @Nullable Object>
Optional<@NonNull V> tryRemove(Map<K,V> map,
 K key)

Removes a mapping for the given key, if one exists.

Returns:

a present Optional of the value associated with the given key, if one existed.

obtain

public static <K extends @Nullable Object,
V extends @Nullable Object>
@NonNull V obtain(Map<K,V> map,
 K key)

Gets the value to which the given key is mapped or throws an exception.

Unlike Map.get(Object), with this method the compiler verifies type of the key argument.

Returns:

the non-null value for the given key

Throws:

IllegalArgumentException - if the given map does not contain a non-null value for the given key.