Move gson to its own folder

[unical.git] / gson / com / google / gson / internal / bind / CollectionTypeAdapterFactory.java

diff --git a/gson/com/google/gson/internal/bind/CollectionTypeAdapterFactory.java b/gson/com/google/gson/internal/bind/CollectionTypeAdapterFactory.java
new file mode 100644 (file)
index 0000000..0b95445
--- /dev/null
+++ b/gson/com/google/gson/internal/bind/CollectionTypeAdapterFactory.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2011 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.gson.internal.bind;
+
+import com.google.gson.Gson;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.internal.$Gson$Types;
+import com.google.gson.internal.ConstructorConstructor;
+import com.google.gson.internal.ObjectConstructor;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.Collection;
+
+/**
+ * Adapt a homogeneous collection of objects.
+ */
+public final class CollectionTypeAdapterFactory implements TypeAdapterFactory {
+  private final ConstructorConstructor constructorConstructor;
+
+  public CollectionTypeAdapterFactory(ConstructorConstructor constructorConstructor) {
+    this.constructorConstructor = constructorConstructor;
+  }
+
+  public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
+    Type type = typeToken.getType();
+
+    Class<? super T> rawType = typeToken.getRawType();
+    if (!Collection.class.isAssignableFrom(rawType)) {
+      return null;
+    }
+
+    Type elementType = $Gson$Types.getCollectionElementType(type, rawType);
+    TypeAdapter<?> elementTypeAdapter = gson.getAdapter(TypeToken.get(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);
+    return result;
+  }
+
+  private static final class Adapter<E> extends TypeAdapter<Collection<E>> {
+    private final TypeAdapter<E> elementTypeAdapter;
+    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<E>(context, elementTypeAdapter, elementType);
+      this.constructor = constructor;
+    }
+
+    public Collection<E> read(JsonReader in) throws IOException {
+      if (in.peek() == JsonToken.NULL) {
+        in.nextNull();
+        return null;
+      }
+
+      Collection<E> collection = constructor.construct();
+      in.beginArray();
+      while (in.hasNext()) {
+        E instance = elementTypeAdapter.read(in);
+        collection.add(instance);
+      }
+      in.endArray();
+      return collection;
+    }
+
+    public void write(JsonWriter out, Collection<E> collection) throws IOException {
+      if (collection == null) {
+        out.nullValue();
+        return;
+      }
+
+      out.beginArray();
+      for (E element : collection) {
+        elementTypeAdapter.write(out, element);
+      }
+      out.endArray();
+    }
+  }
+}