Simplify collection type adapters slightly. (#2791)

* Simplify collection type adapters slightly. By moving some computations to the factory, we can pass fewer parameters to the constructor. * Fix formatting.

Author: eamonnmcmanus

gson/src/main/java/com/google/gson/internal/bind/CollectionTypeAdapterFactory.java

@@ -49,10 +49,12 @@ public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
 
  Type elementType = $Gson$Types.getCollectionElementType(type, rawType);
  TypeAdapter<?> elementTypeAdapter = gson.getAdapter(TypeToken.get(elementType));
+ TypeAdapter<?> wrappedTypeAdapter =
+ new TypeAdapterRuntimeTypeWrapper<>(gson, elementTypeAdapter, elementType);
  ObjectConstructor<T> constructor = constructorConstructor.get(typeToken);
 
  @SuppressWarnings({"unchecked", "rawtypes"}) // create() doesn't define a type parameter
- TypeAdapter<T> result = new Adapter(gson, elementType, elementTypeAdapter, constructor);
+ TypeAdapter<T> result = new Adapter(wrappedTypeAdapter, constructor);
  return result;
  }
 
@@ -61,12 +63,8 @@ private static final class Adapter<E> extends TypeAdapter<Collection<E>> {
  private final ObjectConstructor<? extends Collection<E>> constructor;
 
  public Adapter(
- Gson context,
- Type elementType,
- TypeAdapter<E> elementTypeAdapter,
- ObjectConstructor<? extends Collection<E>> constructor) {
- this.elementTypeAdapter =
- new TypeAdapterRuntimeTypeWrapper<>(context, elementTypeAdapter, elementType);
+ TypeAdapter<E> elementTypeAdapter, ObjectConstructor<? extends Collection<E>> constructor) {
+ this.elementTypeAdapter = elementTypeAdapter;
  this.constructor = constructor;
  }
 

gson/src/main/java/com/google/gson/internal/bind/MapTypeAdapterFactory.java

@@ -132,15 +132,19 @@ public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
  }
 
  Type[] keyAndValueTypes = $Gson$Types.getMapKeyAndValueTypes(type, rawType);
- TypeAdapter<?> keyAdapter = getKeyAdapter(gson, keyAndValueTypes[0]);
- TypeAdapter<?> valueAdapter = gson.getAdapter(TypeToken.get(keyAndValueTypes[1]));
+ Type keyType = keyAndValueTypes[0];
+ Type valueType = keyAndValueTypes[1];
+ TypeAdapter<?> keyAdapter = getKeyAdapter(gson, keyType);
+ TypeAdapter<?> wrappedKeyAdapter =
+ new TypeAdapterRuntimeTypeWrapper<>(gson, keyAdapter, keyType);
+ TypeAdapter<?> valueAdapter = gson.getAdapter(TypeToken.get(valueType));
+ TypeAdapter<?> wrappedValueAdapter =
+ new TypeAdapterRuntimeTypeWrapper<>(gson, valueAdapter, valueType);
  ObjectConstructor<T> constructor = constructorConstructor.get(typeToken);
 
  @SuppressWarnings({"unchecked", "rawtypes"})
  // we don't define a type parameter for the key or value types
- TypeAdapter<T> result =
- new Adapter(
- gson, keyAndValueTypes[0], keyAdapter, keyAndValueTypes[1], valueAdapter, constructor);
+ TypeAdapter<T> result = new Adapter(wrappedKeyAdapter, wrappedValueAdapter, constructor);
  return result;
  }
 
@@ -157,15 +161,11 @@ private final class Adapter<K, V> extends TypeAdapter<Map<K, V>> {
  private final ObjectConstructor<? extends Map<K, V>> constructor;
 
  public Adapter(
- Gson context,
- Type keyType,
  TypeAdapter<K> keyTypeAdapter,
- Type valueType,
  TypeAdapter<V> valueTypeAdapter,
  ObjectConstructor<? extends Map<K, V>> constructor) {
- this.keyTypeAdapter = new TypeAdapterRuntimeTypeWrapper<>(context, keyTypeAdapter, keyType);
- this.valueTypeAdapter =
- new TypeAdapterRuntimeTypeWrapper<>(context, valueTypeAdapter, valueType);
+ this.keyTypeAdapter = keyTypeAdapter;
+ this.valueTypeAdapter = valueTypeAdapter;
  this.constructor = constructor;
  }