org.apache.streams.data.MoreoverXmlActivitySerializer.java Source code

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Here is the source code for org.apache.streams.data.MoreoverXmlActivitySerializer.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 *
 *   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 org.apache.streams.data;

import com.moreover.api.Article;
import com.moreover.api.ArticlesResponse;
import com.moreover.api.ObjectFactory;
import org.apache.commons.lang.SerializationException;
import org.apache.streams.data.util.MoreoverUtils;
import org.apache.streams.pojo.json.Activity;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import java.io.StringReader;
import java.util.LinkedList;
import java.util.List;

/**
 * Deserializes the Moreover Article XML and converts it to an instance of {@link Activity}
 */
public class MoreoverXmlActivitySerializer implements ActivitySerializer<String> {

    //JAXBContext is threadsafe (supposedly)
    private final JAXBContext articleContext;
    private final JAXBContext articlesContext;

    public MoreoverXmlActivitySerializer() {
        articleContext = createContext(Article.class);
        articlesContext = createContext(ArticlesResponse.class);
    }

    @Override
    public String serializationFormat() {
        return "application/xml+vnd.moreover.com.v1";
    }

    @Override
    public String serialize(Activity deserialized) {
        throw new UnsupportedOperationException("Cannot currently serialize to Moreover");
    }

    @Override
    public Activity deserialize(String serialized) {
        Article article = deserializeMoreover(serialized);
        return MoreoverUtils.convert(article);
    }

    @Override
    public List<Activity> deserializeAll(List<String> serializedList) {
        List<Activity> activities = new LinkedList<Activity>();
        for (String item : serializedList) {
            ArticlesResponse response = deserializeMoreoverResponse(item);
            for (Article article : response.getArticles().getArticle()) {
                activities.add(MoreoverUtils.convert(article));
            }
        }
        return activities;
    }

    private Article deserializeMoreover(String serialized) {
        try {
            Unmarshaller unmarshaller = articleContext.createUnmarshaller();
            return (Article) unmarshaller.unmarshal(new StringReader(serialized));
        } catch (JAXBException e) {
            throw new SerializationException("Unable to deserialize Moreover data", e);
        }
    }

    private ArticlesResponse deserializeMoreoverResponse(String serialized) {
        try {
            Unmarshaller unmarshaller = articlesContext.createUnmarshaller();
            return ((JAXBElement<ArticlesResponse>) unmarshaller.unmarshal(new StringReader(serialized)))
                    .getValue();
        } catch (JAXBException e) {
            throw new SerializationException("Unable to deserialize Moreover data", e);
        }
    }

    private JAXBContext createContext(Class articleClass) {
        JAXBContext context;
        try {
            context = JAXBContext.newInstance(articleClass.getPackage().getName(),
                    ObjectFactory.class.getClassLoader());
        } catch (JAXBException e) {
            throw new IllegalStateException("Unable to create JAXB Context for Moreover data", e);
        }
        return context;
    }
}