diff options
Diffstat (limited to 'gson/src/main/java/org/onap/policy/common/gson/internal/JacksonTypeAdapter.java')
-rw-r--r-- | gson/src/main/java/org/onap/policy/common/gson/internal/JacksonTypeAdapter.java | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/JacksonTypeAdapter.java b/gson/src/main/java/org/onap/policy/common/gson/internal/JacksonTypeAdapter.java new file mode 100644 index 00000000..1171fd4d --- /dev/null +++ b/gson/src/main/java/org/onap/policy/common/gson/internal/JacksonTypeAdapter.java @@ -0,0 +1,108 @@ +/* + * ============LICENSE_START======================================================= + * ONAP + * ================================================================================ + * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved. + * ================================================================================ + * 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. + * ============LICENSE_END========================================================= + */ + +package org.onap.policy.common.gson.internal; + +import com.google.gson.Gson; +import com.google.gson.JsonElement; +import com.google.gson.JsonObject; +import com.google.gson.TypeAdapter; +import com.google.gson.stream.JsonReader; +import com.google.gson.stream.JsonWriter; +import java.io.IOException; +import java.util.List; + + +/** + * Adapter for a single class that implements a jackson-style behavior. + * + * @param <T> type of class on which the adapter works + */ +public class JacksonTypeAdapter<T> extends TypeAdapter<T> { + + /** + * Used to create an object of the given class. + */ + private final TypeAdapter<T> delegate; + + /** + * Used to serialize/deserialize a JsonElement. + */ + private final TypeAdapter<JsonElement> elementAdapter; + + /** + * Serializers for each item within the object. + */ + private final Serializer[] serializers; + + /** + * Deserializers for each item within the object. + */ + private final Deserializer[] deserializers; + + /** + * Constructs the object. + * + * @param gson the associated gson object + * @param delegate default constructor for the type + * @param serializers the serializers to use to serialize items within the object + * @param deserializers the deserializers to use to deserialize items into the object + */ + public JacksonTypeAdapter(Gson gson, TypeAdapter<T> delegate, List<Serializer> serializers, + List<Deserializer> deserializers) { + this.delegate = delegate; + this.elementAdapter = gson.getAdapter(JsonElement.class); + this.serializers = serializers.toArray(new Serializer[0]); + this.deserializers = deserializers.toArray(new Deserializer[0]); + } + + @Override + public void write(JsonWriter out, T value) throws IOException { + JsonElement tree = delegate.toJsonTree(value); + + if (tree.isJsonObject()) { + JsonObject jsonObj = tree.getAsJsonObject(); + + // serialize each item from the value into the target tree + for (Serializer serializer : serializers) { + serializer.addToTree(value, jsonObj); + } + } + + elementAdapter.write(out, tree); + } + + @Override + public T read(JsonReader in) throws IOException { + JsonElement tree = elementAdapter.read(in); + T object = delegate.fromJsonTree(tree); + + if (tree.isJsonObject()) { + JsonObject jsonObj = tree.getAsJsonObject(); + + // deserialize each item from the tree into the target object + for (Deserializer dser : deserializers) { + dser.getFromTree(jsonObj, object); + } + } + + return object; + } +} |