com.talvish.tales.serialization.json.translators.JsonObjectToVoidTranslator.java Source code

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Here is the source code for com.talvish.tales.serialization.json.translators.JsonObjectToVoidTranslator.java

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// ***************************************************************************
// *  Copyright 2014 Joseph Molnar
// *
// *  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.talvish.tales.serialization.json.translators;

import com.google.gson.JsonNull;
import com.google.gson.JsonObject;
import com.talvish.tales.parts.translators.TranslationException;
import com.talvish.tales.parts.translators.Translator;

/**
 * Translator is meant to fail if data is being sent for a void.
 * @author jmolnar
 *
 */
public class JsonObjectToVoidTranslator implements Translator {
    /**
     * Empty default constructor.
     */
    public JsonObjectToVoidTranslator() {
    }

    /**
     * Called when a translation is to occur for void, but generally
     * it will only ever receive null, JsonNull or empty JsonObject's
     * and that is fine, anything else is a problem (since this is for
     * void)
     */
    @Override
    public Object translate(Object anObject) {
        if (anObject == null || anObject.equals(JsonNull.INSTANCE)) {
            return null;
        } else {
            try {
                JsonObject jsonObject = (JsonObject) anObject;

                if (jsonObject.entrySet().size() != 0) {
                    throw new TranslationException("should not be receiving void data");
                } else {
                    return null; // no data here, so let's return null
                }

            } catch (ClassCastException e) {
                throw new TranslationException(e);
            }
        }
    }
}