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authorLiam Fallon <liam.fallon@est.tech>2019-02-13 13:44:37 +0000
committerGerrit Code Review <gerrit@onap.org>2019-02-13 13:44:37 +0000
commit2826996b8637671c68f1ac301a13e37bf445a360 (patch)
tree8f45f11ceb3371ace3b66773cbe2ce879e06dce3 /gson/src/main/java/org/onap
parent15fc9d176360a6cc2f7e7c49b96fdf4142d48159 (diff)
parentd7df51a00c9ec3eca4fa5e6f784ba4d52d4f9f89 (diff)
Merge "Add jackson behavior for fields"
Diffstat (limited to 'gson/src/main/java/org/onap')
-rw-r--r--gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java181
-rw-r--r--gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java72
-rw-r--r--gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java80
3 files changed, 333 insertions, 0 deletions
diff --git a/gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java b/gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java
new file mode 100644
index 00000000..67c51449
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java
@@ -0,0 +1,181 @@
+/*
+ * ============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.Field;
+import java.util.ArrayList;
+import java.util.List;
+import org.onap.policy.common.gson.internal.ClassWalker;
+import org.onap.policy.common.gson.internal.Deserializer;
+import org.onap.policy.common.gson.internal.FieldDeserializer;
+import org.onap.policy.common.gson.internal.FieldSerializer;
+import org.onap.policy.common.gson.internal.Serializer;
+
+/**
+ * Factory that serializes/deserializes class fields following the normal behavior of
+ * jackson. Supports the following annotations:
+ * <ul>
+ * <li>GsonJsonIgnore</li>
+ * <li>GsonJsonProperty</li>
+ * </ul>
+ *
+ * <p>Note: {@link JacksonExclusionStrategy} must also be registered with the gson object.
+ */
+public class JacksonFieldAdapterFactory 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(Field.class).isEmpty() && data.getOutProps(Field.class).isEmpty()) {
+ // no fields to serialize
+ return null;
+ }
+
+ return new JacksonFieldAdapter<>(gson, data, gson.getDelegateAdapter(this, type));
+ }
+
+ /**
+ * Adapter for a single class.
+ *
+ * @param <T> type of class on which the adapter works
+ */
+ private static class JacksonFieldAdapter<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 JacksonFieldAdapter(Gson gson, ClassWalker data, TypeAdapter<T> delegate) {
+ this.delegate = delegate;
+
+ this.elementAdapter = gson.getAdapter(JsonElement.class);
+
+ // create serializers
+ this.serializers = makeSerializers(gson, data).toArray(new Serializer[0]);
+
+ // create deserializers
+ this.deserializers = makeDeserializers(gson, data).toArray(new Deserializer[0]);
+ }
+
+ /**
+ * Creates a complete list of serializers.
+ *
+ * @param gson the associated gson object
+ * @param data data used to configure the serializers
+ * @return a list of all serializers
+ */
+ private List<Serializer> makeSerializers(Gson gson, ClassWalker data) {
+ List<Serializer> ser = new ArrayList<Serializer>();
+
+ data.getOutProps(Field.class).forEach(field -> ser.add(new FieldSerializer(gson, field)));
+
+ return ser;
+ }
+
+ /**
+ * Creates a complete list of deserializers.
+ *
+ * @param gson the associated gson object
+ * @param data data used to configure the deserializers
+ * @return a list of all deserializers
+ */
+ private List<Deserializer> makeDeserializers(Gson gson, ClassWalker data) {
+ List<Deserializer> deser = new ArrayList<Deserializer>();
+
+ data.getInProps(Field.class).forEach(field -> deser.add(new FieldDeserializer(gson, field)));
+
+ 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;
+ }
+ }
+}
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java
new file mode 100644
index 00000000..14a432d1
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java
@@ -0,0 +1,72 @@
+/*
+ * ============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.JsonParseException;
+import java.lang.reflect.Field;
+
+/**
+ * De-serializer for fields that are exposed.
+ */
+public class FieldDeserializer extends Adapter implements Deserializer {
+
+ public static final String SET_ERR = "cannot set field: ";
+
+ /**
+ * Field within the object.
+ */
+ private final Field field;
+
+ /**
+ * Constructs the object.
+ *
+ * @param gson Gson object providing type adapters
+ * @param field field within the object
+ */
+ public FieldDeserializer(Gson gson, Field field) {
+ super(gson, field);
+
+ this.field = field;
+
+ field.setAccessible(true);
+ }
+
+ @Override
+ public void getFromTree(JsonObject source, Object target) {
+ JsonElement jsonEl = source.get(getPropName());
+ if (jsonEl == null || jsonEl.isJsonNull()) {
+ return;
+ }
+
+ Object value = fromJsonTree(jsonEl);
+
+ try {
+ field.set(target, value);
+
+ } catch (IllegalArgumentException | IllegalAccessException e) {
+ throw new JsonParseException(makeError(SET_ERR), e);
+ }
+ }
+
+}
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java
new file mode 100644
index 00000000..1c9d8b37
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java
@@ -0,0 +1,80 @@
+/*
+ * ============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.JsonNull;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import java.lang.reflect.Field;
+
+/**
+ * Serializer for fields that are exposed.
+ */
+public class FieldSerializer extends Adapter implements Serializer {
+
+ public static final String GET_ERR = "cannot get field: ";
+
+ /**
+ * Field within the object.
+ */
+ private final Field field;
+
+ /**
+ * Constructs the object.
+ *
+ * @param gson Gson object providing type adapters
+ * @param field field within the object
+ */
+ public FieldSerializer(Gson gson, Field field) {
+ super(gson, field);
+
+ this.field = field;
+
+ field.setAccessible(true);
+ }
+
+ @Override
+ public void addToTree(Object source, JsonObject target) {
+ Object value;
+ try {
+ value = getFromObject(source);
+
+ } catch (IllegalArgumentException | IllegalAccessException e) {
+ throw new JsonParseException(makeError(GET_ERR), e);
+ }
+
+ JsonElement jsonEl = (value == null ? JsonNull.INSTANCE : toJsonTree(value));
+ target.add(getPropName(), jsonEl);
+ }
+
+ /**
+ * Gets the field from the source object. Overridden during junit testing.
+ *
+ * @param source object containing the field
+ * @return the field's value
+ * @throws IllegalAccessException if an error occurs
+ */
+ protected Object getFromObject(Object source) throws IllegalAccessException {
+ return field.get(source);
+ }
+}