1 files changed, 202 insertions, 0 deletions
diff --git a/gson/src/main/java/org/onap/policy/common/gson/JacksonMethodAdapterFactory.java b/gson/src/main/java/org/onap/policy/common/gson/JacksonMethodAdapterFactory.java
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+/*
+ * ============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;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import org.onap.policy.common.gson.internal.AnyGetterSerializer;
+import org.onap.policy.common.gson.internal.AnySetterDeserializer;
+import org.onap.policy.common.gson.internal.ClassWalker;
+import org.onap.policy.common.gson.internal.Deserializer;
+import org.onap.policy.common.gson.internal.MethodDeserializer;
+import org.onap.policy.common.gson.internal.MethodSerializer;
+import org.onap.policy.common.gson.internal.Serializer;
+
+/**
+ * Factory that serializes/deserializes class methods following the normal behavior of
+ * jackson. Supports the following annotations:
+ * <ul>
+ * <li>GsonJsonIgnore</li>
+ * <li>GsonJsonProperty</li>
+ * <li>GsonJsonAnyGetter</li>
+ * <li>GsonJsonAnySetter</li>
+ * </ul>
+ */
+public class JacksonMethodAdapterFactory implements TypeAdapterFactory {
+
+    @Override
+    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+        Class<? super T> clazz = type.getRawType();
+
+        if (!JacksonExclusionStrategy.isManaged(clazz)) {
+            return null;
+        }
+
+        ClassWalker data = new ClassWalker();
+        data.walkClassHierarchy(clazz);
+
+        if (data.getInProps(Method.class).isEmpty() && data.getOutProps(Method.class).isEmpty()) {
+            if (data.getAnyGetter() == null && data.getAnySetter() == null) {
+                // no methods to serialize
+                return null;
+            }
+        }
+
+        return new JacksonMethodAdapter<>(gson, data, gson.getDelegateAdapter(this, type));
+    }
+
+    /**
+     * Adapter for a single class.
+     *
+     * @param <T> type of class on which the adapter works
+     */
+    private static class JacksonMethodAdapter<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 data data used to configure the adapter
+         * @param delegate default constructor for the type
+         */
+        public JacksonMethodAdapter(Gson gson, ClassWalker data, TypeAdapter<T> delegate) {
+            this.delegate = delegate;
+
+            this.elementAdapter = gson.getAdapter(JsonElement.class);
+
+            Set<String> unliftedProps = new HashSet<>();
+            unliftedProps.addAll(data.getInNotIgnored());
+            unliftedProps.addAll(data.getOutNotIgnored());
+
+            // create serializers
+            this.serializers = makeSerializers(gson, data, unliftedProps).toArray(new Serializer[0]);
+
+            // create deserializers
+            this.deserializers = makeDeserializers(gson, data, unliftedProps).toArray(new Deserializer[0]);
+        }
+
+        /**
+         * Creates a complete list of serializers.
+         *
+         * @param gson the associated gson object
+         * @param data data used to configure the serializers
+         * @param unliftedProps properties that should not be lowered by "any-getters"
+         * @return a list of all serializers
+         */
+        private List<Serializer> makeSerializers(Gson gson, ClassWalker data, Set<String> unliftedProps) {
+            List<Serializer> ser = new ArrayList<Serializer>();
+
+            if (data.getAnyGetter() != null) {
+                ser.add(new AnyGetterSerializer(gson, unliftedProps, data.getAnyGetter()));
+            }
+
+            data.getOutProps(Method.class).forEach(method -> ser.add(new MethodSerializer(gson, method)));
+
+            return ser;
+        }
+
+        /**
+         * Creates a complete list of deserializers.
+         *
+         * @param gson the associated gson object
+         * @param data data used to configure the deserializers
+         * @param unliftedProps properties that should not be lifted by "any-setters"
+         * @return a list of all deserializers
+         */
+        private List<Deserializer> makeDeserializers(Gson gson, ClassWalker data, Set<String> unliftedProps) {
+            List<Deserializer> deser = new ArrayList<Deserializer>();
+
+            if (data.getAnySetter() != null) {
+                deser.add(new AnySetterDeserializer(gson, unliftedProps, data.getAnySetter()));
+            }
+
+            data.getInProps(Method.class).forEach(method -> deser.add(new MethodDeserializer(gson, method)));
+
+            return deser;
+        }
+
+        @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;
+        }
+    }
+}