com.googlecode.wicketcontinuouscalendar.jackson.JsonRenderer.java Source code

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Here is the source code for com.googlecode.wicketcontinuouscalendar.jackson.JsonRenderer.java

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/**
 *   Copyright (C) ${year} Wicket Continuous Calendar (http://Wicket-Continuous-Calendar.GoogleCode.com/)
 *
 *   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.googlecode.wicketcontinuouscalendar.jackson;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.googlecode.wicketcontinuouscalendar.options.Function;

/**
 * A renderer for rendering jQueryContinuousCalendar options into JSON objects based on the
 * Jackson Mapping library.
 * 
 * @author Paul Bors (Paul@Bors.ws)
 * 
 */
public class JsonRenderer {

    private final ObjectMapper jacksonMapper;

    private final ContinuousCalendarJacksonModule jacksonModule;

    /**
     * The default mapper can be used to bypass the serializers registered in the
     * {@link ContinuousCalendarJacksonModule}.
     */
    public final static ObjectMapper DEFAULT_MAPPER = createDefaultObjectMapper();

    public JsonRenderer() {
        this.jacksonModule = new ContinuousCalendarJacksonModule();
        this.jacksonModule.addSerializer(Function.class, new FunctionSerializer());
        this.jacksonMapper = createJacksonMapper();
    }

    /**
     * This method gives the opportunity to add a custom serializer to serializer
     * one of the ContinuousCalendar option classes. It may be necessary to serialize
     * certain option classes differently for different web frameworks.
     * 
     * @param clazz
     *          the option class
     * @param serializer
     *          the serializer responsible for serializing objects of the option
     *          class.
     */
    public <T> void addSerializer(final Class<T> clazz, final JsonSerializer<T> serializer) {
        this.jacksonModule.addSerializer(clazz, serializer);
    }

    private ObjectMapper createJacksonMapper() {
        ObjectMapper mapper = createDefaultObjectMapper();
        mapper.registerModule(this.jacksonModule);
        return mapper;
    }

    private static ObjectMapper createDefaultObjectMapper() {
        ObjectMapper mapper = new ObjectMapper();
        mapper.enable(SerializationFeature.INDENT_OUTPUT);
        mapper.disable(SerializationFeature.WRITE_NULL_MAP_VALUES);
        mapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
        mapper.setSerializationInclusion(Include.NON_NULL);
        return mapper;
    }

    public String toJson(final Object object) {
        try {
            return this.jacksonMapper.writeValueAsString(object);
        } catch (Exception e) {
            throw new RuntimeException(
                    "Error trying to serialize object of type " + object.getClass().getName() + " into JSON!", e);
        }
    }
}