org.vertx.java.http.eventbusbridge.util.SerializationHelper.java Source code

Introduction

Here is the source code for org.vertx.java.http.eventbusbridge.util.SerializationHelper.java

Source

/**
 * Copyright (c) 2014 j2ro
 *
 * 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 org.vertx.java.http.eventbusbridge.util;

import java.io.StringWriter;

import javax.ws.rs.core.MediaType;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

import org.vertx.java.http.eventbusbridge.model.EventBusBridgeResponse;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

/**
 * Class provides some utility methods for serialisation to JSON and XML.
 *
 * @author j2ro
 */
public final class SerializationHelper {

    private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
    private static final JAXBContext JAXB_CONTEXT;

    static {
        try {
            JAXB_CONTEXT = JAXBContext.newInstance(EventBusBridgeResponse.class);
            JSON_MAPPER.setSerializationInclusion(Include.NON_NULL);
            JSON_MAPPER.enable(SerializationFeature.INDENT_OUTPUT);
        } catch (JAXBException e) {
            throw new RuntimeException("Class initialization failed due to JAXBException", e);
        }
    }

    private SerializationHelper() {
    }

    /**
     * Serialises object to JSON or XML depending on the media type provided.
     * @param object Object to serialise
     * @param mediaType Media type to serialise to ('application/xml' or 'application/json')
     * @return Serialised object
     * @throws JsonProcessingException if there was a problem serializing to Json
     * @throws JAXBException if there was a problem serializing to XML
     */
    public static String serialize(final Object object, final String mediaType)
            throws JsonProcessingException, JAXBException {
        if (MediaType.APPLICATION_JSON.equals(mediaType)) {
            return toJson(object);
        } else if (MediaType.APPLICATION_XML.equals(mediaType)) {
            return toXml(object);
        } else {
            throw new IllegalArgumentException(
                    "Unsupported media type serialization requested for response: " + mediaType);
        }
    }

    private static String toJson(final Object jsonObject) throws JsonProcessingException {
        return JSON_MAPPER.writeValueAsString(jsonObject);
    }

    private static String toXml(final Object xmlObject) throws JAXBException {
        StringWriter writer = new StringWriter();
        Marshaller jaxbMarshaller = JAXB_CONTEXT.createMarshaller();
        jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        jaxbMarshaller.marshal(xmlObject, writer);
        return writer.toString();
    }
}