data.JSONDataInserter.java Source code

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Here is the source code for data.JSONDataInserter.java

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/**
 * <copyright>
 *
 * Copyright (c) 2014 http://www.big.tuwien.ac.at All rights reserved. This
 * program and the accompanying materials are made available under the terms of
 * the Eclipse Public License v1.0 which accompanies this distribution, and is
 * available at http://www.eclipse.org/legal/epl-v10.html
 *
 * </copyright>
 */
package data;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.Type;
import java.util.List;

import play.db.jpa.Transactional;
import models.Answer;
import models.Category;
import models.JeopardyDAO;
import models.Question;

import com.google.common.base.Charsets;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.reflect.TypeToken;

public class JSONDataInserter {

    private static Gson createGson() {
        GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder.registerTypeAdapter(Category.class, new CategoryDeserializer());
        gsonBuilder.registerTypeAdapter(Question.class, new QuestionDeserializer());
        gsonBuilder.registerTypeAdapter(Answer.class, new AnswerDeserializer());
        return gsonBuilder.create();
    }

    public static List<Category> loadCategoryData(InputStream inputStream) {
        Gson gson = createGson();
        Type collectionType = new TypeToken<List<Category>>() {
        }.getType();

        List<Category> categories = gson.fromJson(new InputStreamReader(inputStream, Charsets.UTF_8),
                collectionType);

        return categories;
    }

    @Transactional
    public static List<Category> insertData(InputStream inputStream) {
        List<Category> jsonCategories = loadCategoryData(inputStream);
        for (Category category : jsonCategories)
            JeopardyDAO.INSTANCE.persist(category);
        return jsonCategories;
    }
}

class CategoryDeserializer implements JsonDeserializer<Category> {

    @Override
    public Category deserialize(JsonElement json, Type type, JsonDeserializationContext context)
            throws JsonParseException {

        Category category = new Category();
        JsonObject object = json.getAsJsonObject();

        category.setNameDE(object.get("nameDE").getAsString());
        category.setNameEN(object.get("nameEN").getAsString());

        for (JsonElement jsonQuestion : object.get("questions").getAsJsonArray()) {
            Question question = context.deserialize(jsonQuestion, new TypeToken<Question>() {
            }.getType());
            category.addQuestion(question);
        }

        return category;
    }

}

class QuestionDeserializer implements JsonDeserializer<Question> {

    @Override
    public Question deserialize(JsonElement json, Type type, JsonDeserializationContext context)
            throws JsonParseException {

        Question question = new Question();

        JsonObject object = json.getAsJsonObject();
        question.setTextDE(object.get("textDE").getAsString());
        question.setTextEN(object.get("textEN").getAsString());
        question.setValue(object.get("value").getAsInt());

        for (JsonElement wrongAnswer : object.get("wrongAnswers").getAsJsonArray()) {
            Answer answer = context.deserialize(wrongAnswer, new TypeToken<Answer>() {
            }.getType());
            question.addWrongAnswer(answer);
        }

        for (JsonElement correctAnswer : object.get("rightAnswers").getAsJsonArray()) {
            Answer answer = context.deserialize(correctAnswer, new TypeToken<Answer>() {
            }.getType());
            question.addRightAnswer(answer);
        }

        return question;
    }
}

class AnswerDeserializer implements JsonDeserializer<Answer> {

    @Override
    public Answer deserialize(JsonElement json, Type type, JsonDeserializationContext context)
            throws JsonParseException {

        Answer answer = new Answer();
        JsonObject object = json.getAsJsonObject();
        answer.setTextDE(object.get("textDE").getAsString());
        answer.setTextEN(object.get("textEN").getAsString());

        return answer;
    }

}