Introduced the Apache Commons Collections KeyValue support

README.md

@@ -98,6 +98,7 @@ No `ext-gson` dependencies are bundled or planned to be bundled, so all dependen
 * `org.apache.commons.collections4.BidiMap`
 * `org.apache.commons.collections4.BoundedCollection`
 * `org.apache.commons.collections4.IterableMap`
+* `org.apache.commons.collections4.KeyValue`
 * `org.apache.commons.collections4.MultiSet`
 * `org.apache.commons.collections4.MultiValuedMap`
 

src/main/java/lsh/ext/gson/ext/org/apache/commons/collections4/ApacheCommonsCollections4Module.java

@@ -11,6 +11,7 @@
 import org.apache.commons.collections4.BidiMap;
 import org.apache.commons.collections4.BoundedCollection;
 import org.apache.commons.collections4.IterableMap;
+import org.apache.commons.collections4.KeyValue;
 import org.apache.commons.collections4.MultiSet;
 import org.apache.commons.collections4.MultiValuedMap;
 
@@ -31,6 +32,9 @@ public final class ApacheCommonsCollections4Module
 	@Setter
 	private ITypeAdapterFactory<? extends IterableMap<String, ?>> iterableMapTypeAdapterFactory = ApacheCommonsCollections4TypeAdapterFactory.defaultForIterableMap;
 
+	@Setter
+	private ITypeAdapterFactory<? extends KeyValue<String, ?>> keyTypeAdapterFactory = ApacheCommonsCollections4TypeAdapterFactory.defaultForKeyValue;
+
 	@Setter
 	private ITypeAdapterFactory<? extends MultiSet<?>> multiSetTypeAdapterFactory = ApacheCommonsCollections4TypeAdapterFactory.defaultForMultiSet;
 
@@ -44,6 +48,7 @@ public IModule build() {
 				bidiMapTypeAdapterFactory,
 				boundedCollectionTypeAdapterFactory,
 				iterableMapTypeAdapterFactory,
+				keyTypeAdapterFactory,
 				multiSetTypeAdapterFactory,
 				multiValuedMapTypeAdapterFactory
 		);

src/main/java/lsh/ext/gson/ext/org/apache/commons/collections4/ApacheCommonsCollections4TypeAdapter.java

@@ -2,6 +2,7 @@
 
 import java.util.AbstractMap;
 import java.util.Map;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -11,11 +12,13 @@
 import lsh.ext.gson.Container2TypeAdapter;
 import lsh.ext.gson.IBuilder1;
 import lsh.ext.gson.IBuilder2;
+import lsh.ext.gson.SingleEntryTypeAdapter;
 import org.apache.commons.collections4.Bag;
 import org.apache.commons.collections4.BidiMap;
 import org.apache.commons.collections4.BoundedCollection;
 import org.apache.commons.collections4.IterableMap;
 import org.apache.commons.collections4.IteratorUtils;
+import org.apache.commons.collections4.KeyValue;
 import org.apache.commons.collections4.MultiSet;
 import org.apache.commons.collections4.MultiValuedMap;
 
@@ -104,6 +107,22 @@ public static <K, V> TypeAdapter<IterableMap<K, V>> forIterableMap(
 		);
 	}
 
+	public static <K, V> TypeAdapter<KeyValue<K, V>> forKeyValue(
+			final TypeAdapter<V> valueTypeAdapter,
+			final BiFunction<? super K, ? super V, ? extends KeyValue<K, V>> createEntry,
+			final Function<? super K, String> encodeKey,
+			final Function<? super String, ? extends K> decodeKey
+	) {
+		return SingleEntryTypeAdapter.getInstance(
+				valueTypeAdapter,
+				KeyValue::getKey,
+				KeyValue::getValue,
+				createEntry,
+				encodeKey,
+				decodeKey
+		);
+	}
+
 	public static <E> TypeAdapter<MultiSet<E>> forMultiSet(
 			final TypeAdapter<E> elementTypeAdapter,
 			final Supplier<? extends IBuilder1<? super E, ? extends MultiSet<E>>> builderFactory

src/main/java/lsh/ext/gson/ext/org/apache/commons/collections4/ApacheCommonsCollections4TypeAdapterFactory.java

@@ -1,5 +1,6 @@
 package lsh.ext.gson.ext.org.apache.commons.collections4;
 
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -13,11 +14,13 @@
 import org.apache.commons.collections4.BidiMap;
 import org.apache.commons.collections4.BoundedCollection;
 import org.apache.commons.collections4.IterableMap;
+import org.apache.commons.collections4.KeyValue;
 import org.apache.commons.collections4.MultiSet;
 import org.apache.commons.collections4.MultiValuedMap;
 import org.apache.commons.collections4.bag.HashBag;
 import org.apache.commons.collections4.bidimap.DualHashBidiMap;
 import org.apache.commons.collections4.bidimap.DualLinkedHashBidiMap;
+import org.apache.commons.collections4.keyvalue.UnmodifiableMapEntry;
 import org.apache.commons.collections4.multimap.ArrayListValuedHashMap;
 import org.apache.commons.collections4.multimap.HashSetValuedHashMap;
 import org.apache.commons.collections4.multiset.HashMultiSet;
@@ -124,6 +127,29 @@ public static <V> Supplier<IBuilder2<String, V, IterableMap<String, V>>> default
 		throw new UnsupportedOperationException(String.valueOf(typeToken));
 	}
 
+	public static final ITypeAdapterFactory<KeyValue<String, Object>> defaultForKeyValue = forKeyValue(UnmodifiableMapEntry::new);
+
+	public static <V> ITypeAdapterFactory<KeyValue<String, V>> forKeyValue(
+			final BiFunction<? super String, ? super V, ? extends KeyValue<String, V>> createEntry
+	) {
+		return forKeyValue(createEntry, Function.identity(), Function.identity());
+	}
+
+	public static <K, V> ITypeAdapterFactory<KeyValue<K, V>> forKeyValue(
+			final BiFunction<? super K, ? super V, ? extends KeyValue<K, V>> createEntry,
+			final Function<? super K, String> toKey,
+			final Function<? super String, ? extends K> fromKey
+	) {
+		return ITypeAdapterFactory.forClassHierarchy(
+				KeyValue.class,
+				provider -> ApacheCommonsCollections4TypeAdapter.forKeyValue(provider.getTypeAdapter(1), createEntry, toKey, fromKey)
+		);
+	}
+
+	public static <V> Supplier<IBuilder2<String, V, KeyValue<String, V>>> defaultBuilderForKeyValue(final TypeToken<? super KeyValue<String, V>> typeToken) {
+		throw new UnsupportedOperationException(String.valueOf(typeToken));
+	}
+
 	public static ITypeAdapterFactory<MultiSet<Object>> defaultForMultiSet = forMultiSet(ApacheCommonsCollections4TypeAdapterFactory::defaultBuilderForMultiSet);
 
 	public static <E> ITypeAdapterFactory<MultiSet<E>> forMultiSet(