com.ibm.watson.developer_cloud.util.GsonSingleton.java Source code

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Here is the source code for com.ibm.watson.developer_cloud.util.GsonSingleton.java

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/**
 * Copyright 2017 IBM Corp. All Rights Reserved.
 *
 * 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.ibm.watson.developer_cloud.util;

import java.util.Date;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

/**
 * Gson singleton to be use when transforming from JSON to Java Objects and vise versa. It handles date formatting and
 * pretty print the result
 */
public final class GsonSingleton {

    private static Gson gson;
    private static Gson gsonWithoutPrinting;

    private GsonSingleton() {
        // This is a utility class - no instantiation allowed.
    }

    /**
     * Creates a {@link com.google.gson.Gson} object that can be use to serialize and deserialize Java objects.
     *
     * @param prettyPrint if true the JSON will be pretty printed
     * @return the {@link Gson}
     */
    private static Gson createGson(Boolean prettyPrint) {
        GsonBuilder builder = new GsonBuilder();

        registerTypeAdapters(builder);

        if (prettyPrint) {
            builder.setPrettyPrinting();
        }
        builder.disableHtmlEscaping();
        return builder.create();
    }

    private static void registerTypeAdapters(GsonBuilder builder) {
        // Date serializer and deserializer
        builder.registerTypeAdapter(Date.class, new DateDeserializer());
        builder.registerTypeAdapter(Date.class, new DateSerializer());
    }

    /**
     * Gets the Gson instance.
     *
     * @return the Gson
     */
    public static synchronized Gson getGson() {
        if (gson == null) {
            gson = createGson(true);
        }
        return gson;
    }

    /**
     * Gets the Gson instance.
     *
     * @return the Gson
     */
    public static synchronized Gson getGsonWithoutPrettyPrinting() {
        if (gsonWithoutPrinting == null) {
            gsonWithoutPrinting = createGson(false);
        }
        return gsonWithoutPrinting;
    }
}