com.splicemachine.derby.ddl.InterfaceSerializer.java Source code

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Here is the source code for com.splicemachine.derby.ddl.InterfaceSerializer.java

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/*
 * Copyright 2012 - 2016 Splice Machine, 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.splicemachine.derby.ddl;

import com.google.gson.*;

import java.lang.reflect.Type;

/**
 * Custom gson serializer for interface
 *
 * @author jyuan
 */
public class InterfaceSerializer<T> implements JsonSerializer<T>, JsonDeserializer<T> {

    @Override
    public JsonElement serialize(T object, Type interfaceType, JsonSerializationContext context) {
        final JsonObject wrapper = new JsonObject();
        wrapper.addProperty("type", object.getClass().getName());
        wrapper.add("data", context.serialize(object));
        return wrapper;
    }

    @Override
    public T deserialize(JsonElement elem, Type interfaceType, JsonDeserializationContext context)
            throws JsonParseException {
        final JsonObject wrapper = (JsonObject) elem;
        final JsonElement typeName = get(wrapper, "type");
        final JsonElement data = get(wrapper, "data");
        final Type actualType = typeForName(typeName);
        return context.deserialize(data, actualType);
    }

    private Type typeForName(final JsonElement typeElem) {
        try {
            return Class.forName(typeElem.getAsString());
        } catch (ClassNotFoundException e) {
            throw new JsonParseException(e);
        }
    }

    private JsonElement get(final JsonObject wrapper, String memberName) {
        final JsonElement elem = wrapper.get(memberName);
        if (elem == null)
            throw new JsonParseException(
                    "no '" + memberName + "' member found in what was expected to be an interface wrapper");
        return elem;
    }
}