com.clothcat.hpoolauto.JsonFileHelper.java Source code

Introduction

Here is the source code for com.clothcat.hpoolauto.JsonFileHelper.java

Source

/*
 * The MIT License
 *
 * Copyright 2014 Stephen Stafford <clothcat@gmail.com>.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.clothcat.hpoolauto;

import com.google.gson.GsonBuilder;
import com.google.gson.JsonParser;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;

/**
 * Functionality that wraps JSON objects and writes them to the filsystem
 *
 * @author Stephen Stafford <clothcat@gmail.com>
 */
public class JsonFileHelper {

    /**
     * Reads a JSON Object from the filename passed.
     *
     * When we store json files we add three lines of comment in a wrapping array,
     * so we remove them here and return the json object contained in the wrapper.
     *
     * @param filename
     * @return
     */
    public static JSONObject readFromFile(String filename) {
        try {
            HLogger.log(Level.FINEST, "Attempting to reaad JSON from " + filename);
            File f = new File(Constants.JSON_FILEPATH + filename);
            // if the file sn't there then return an empty JSONObject
            if (!f.exists()) {
                HLogger.log(Level.FINEST, "File did not exist, returning an " + "empty JSONObject");
                return new JSONObject();
            }
            HLogger.log(Level.FINEST, "Constructing JSONArray");
            JSONArray ja = new JSONArray(new JSONTokener(new FileReader(f)));
            HLogger.log(Level.FINEST, "Array fetched:\n" + prettify(ja.toString()));
            // the actual JSONObject we want is element 3 since there are three 
            // lines of comment that start the array
            HLogger.log(Level.FINEST, "Unwrapping and returning: \n" + prettify(ja.getJSONObject(3).toString()));
            return ja.getJSONObject(3);
        } catch (FileNotFoundException | JSONException ex) {
            HLogger.log(Level.SEVERE, "Caught exception in JsonFileHelper.readFromFile.", ex);
            Logger.getLogger(JsonFileHelper.class.getName()).log(Level.SEVERE, null, ex);
        }
        // if we get here someting is seriously broken!
        HLogger.log(Level.SEVERE, "Reached the bottom of JsonFileHelper.readFromFile"
                + "(String filename) method.  Something majorly fucked up!");
        throw new RuntimeException(
                "Reached the bottom of JsonFileHelper." + "readFromFile(String filename) method.");
    }

    public static void writeToFile(JSONObject jo, String filename) {
        HLogger.log(Level.FINEST, "Attempting to write json to " + filename + "\n" + jo.toString());
        // an array wrapper that we use to allow us to put a comment at the top
        // of the file to tell people not to edit
        JSONArray ja = new JSONArray();
        ja.put("This file is part of the HyperPool Automation Tool (HAT)");
        ja.put(" 2014 Stephen Stafford  all rights wossnamed");
        ja.put("DO NOT EDIT THIS FILE BY HAND.  BAD THINGS WILL HAPPEN!!");
        ja.put(jo);
        HLogger.log(Level.FINEST,
                "After wrapping with comments array json looks " + "like: \n" + prettify(ja.toString()));
        String s = ja.toString();
        s = prettify(s);

        File f = new File(Constants.JSON_FILEPATH);
        f.mkdirs();
        f = new File(Constants.JSON_FILEPATH + filename);
        HLogger.log(Level.FINEST, "Attempting to write to file: " + filename);
        try (PrintWriter p = new PrintWriter(f)) {
            p.println(s);
            HLogger.log(Level.FINEST, "Wrote to file: " + filename);
        } catch (FileNotFoundException ex) {
            HLogger.log(Level.SEVERE, "Caught exception whilst trying to write to " + "file: " + filename, ex);
            Logger.getLogger(JsonFileHelper.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    /**
     * Pretty print the passed string and return ut as a string
     */
    public static String prettify(String json) {
        return new GsonBuilder().setPrettyPrinting().create().toJson(new JsonParser().parse(json));
    }
}