com.lonepulse.robozombie.response.Deserializers.java Source code

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Here is the source code for com.lonepulse.robozombie.response.Deserializers.java

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package com.lonepulse.robozombie.response;

/*
 * #%L
 * RoboZombie
 * %%
 * Copyright (C) 2013 - 2014 Lonepulse
 * %%
 * 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.
 * #L%
 */

import java.util.HashMap;
import java.util.Map;

import org.apache.http.HttpResponse;

import com.lonepulse.robozombie.annotation.Entity.ContentType;
import com.lonepulse.robozombie.proxy.InvocationContext;

/**
 * <p>Exposes all available {@link AbstractDeserializer}s, resolves concrete instances of their deserializer 
 * types and mediates communication.</p> 
 * 
 * @version 1.2.0
 * <br><br>
 * @since 1.3.0
 * <br><br>
 * @author <a href="http://sahan.me">Lahiru Sahan Jayasinghe</a>
 */
public enum Deserializers implements Deserializer<Object> {

    /**
     * <p>See {@link PlainDeserializer}.</p>
     * 
     * @since 1.3.0
     */
    RAW(new PlainDeserializer()),

    /**
     * <p>See {@link JsonDeserializer}.</p>
     * 
     * @since 1.3.0
     */
    JSON(new JsonDeserializer()),

    /**
     * <p>See {@link XmlDeserializer}.</p>
     * 
     * @since 1.3.0
     */
    XML(new XmlDeserializer());

    private static final Map<String, AbstractDeserializer<?>> DESERIALIZERS = new HashMap<String, AbstractDeserializer<?>>();

    private final AbstractDeserializer<?> deserializer;

    private Deserializers(AbstractDeserializer<?> deserializer) {

        this.deserializer = deserializer;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Object run(InvocationContext context, HttpResponse response) {

        return this.deserializer.run(context, response);
    }

    /**
     * <p>Retrieves the {@link AbstractDeserializer} which is identified by the given {@link ContentType}.</p>
     * 
     * @param context
     *          the {@link ContentType} whose associated {@link AbstractDeserializer} should be retrieved
     * <br><br>
     * @return the implementation of {@link AbstractDeserializer} which serves the given {@link ContentType}
     * <br><br>
     * @since 1.3.0
     */
    public static final AbstractDeserializer<?> resolve(ContentType deserializerType) {

        switch (deserializerType) {

        case JSON:
            return Deserializers.JSON.deserializer;

        case XML:
            return Deserializers.XML.deserializer;

        case PLAIN:
        case UNDEFINED:
        default:
            return Deserializers.RAW.deserializer;
        }
    }

    /**
     * <p>Retrieves the {@link AbstractDeserializer} which is defined for the given {@link Class}.</p>
     * 
     * @param deserializerType
     *          the {@link Class} whose implementation of {@link AbstractDeserializer} is retrieved
     * <br><br>
     * @return the implementation of {@link AbstractDeserializer} for the given {@link Class}
     * <br><br>
     * @throws DeserializerInstantiationException
     *          if a custom deserializer failed to be instantiated using its <b>default constructor</b> 
     * <br><br>
     * @since 1.3.0
     */
    public static final AbstractDeserializer<?> resolve(Class<? extends AbstractDeserializer<?>> deserializerType) {

        try {

            synchronized (DESERIALIZERS) {

                String key = deserializerType.getName();

                AbstractDeserializer<?> deserializer = DESERIALIZERS.get(key);

                if (deserializer == null) {

                    deserializer = deserializerType.newInstance();
                    DESERIALIZERS.put(key, deserializer);
                }

                return deserializer;
            }
        } catch (Exception e) {

            throw new DeserializerInstantiationException(deserializerType, e);
        }
    }
}