cc.pinel.mangue.storage.AbstractStorage.java Source code

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Here is the source code for cc.pinel.mangue.storage.AbstractStorage.java

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/*
 * Copyright 2014 Roque Pinel
 *
 * 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 cc.pinel.mangue.storage;

import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.io.IOUtils;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

import com.amazon.kindle.kindlet.KindletContext;

/**
 * The abstract classes for storages.
 * 
 * @author Roque Pinel
 *
 */
public abstract class AbstractStorage {
    private final KindletContext context;

    private final String storageFile;

    /**
     * @param context the kindlet context
     * @param storageFile the storage file
     */
    public AbstractStorage(KindletContext context, String storageFile) {
        this.context = context;
        this.storageFile = storageFile;
    }

    /**
     * Clears the storage.
     * 
     * @throws IOException
     */
    public void clear() throws IOException {
        writeJSON(new JSONObject());
    }

    /**
     * @return the storage path
     */
    protected String getPath() {
        return this.context.getHomeDirectory().getAbsolutePath() + "/" + this.storageFile;
    }

    /**
     * Reads the storage JSON.
     * 
     * @return the JSON object
     * @throws ParseException
     * @throws IOException
     */
    protected JSONObject readJSON() throws ParseException, IOException {
        InputStream is = getClass().getResourceAsStream(getPath());

        JSONParser parser = new JSONParser();

        return (JSONObject) parser.parse(IOUtils.toString(is));
    }

    /**
     * Writes the JSON object to the storage.
     * 
     * @param json the JSON object
     * @throws IOException
     */
    protected void writeJSON(JSONObject json) throws IOException {
        FileWriter fw = null;

        try {
            fw = new FileWriter(getPath());

            json.writeJSONString(fw);
        } finally {
            if (fw != null)
                fw.close();
        }
    }

    /**
     * Finds the manga JSON object from the array
     * based on the manga id provided.
     * 
     * @param jsonMangas the array
     * @param mangaId the manga id
     * @return the manga, if found
     */
    protected static JSONObject findManga(JSONArray jsonMangas, String mangaId) {
        for (int i = 0; i < jsonMangas.size(); i++) {
            JSONObject jsonManga = (JSONObject) jsonMangas.get(i);
            Object id = jsonManga == null ? null : jsonManga.get("id");
            if (id.equals(mangaId))
                return jsonManga;
        }
        return null;
    }
}