fi.helsinki.cs.iot.kahvihub.conf.ConfigurationFileParser.java Source code

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Here is the source code for fi.helsinki.cs.iot.kahvihub.conf.ConfigurationFileParser.java

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/*
 * fi.helsinki.cs.iot.kahvihub.conf.ConfigurationFileParser
 * v0.1
 * 2015
 *
 * Copyright 2015 University of Helsinki
 * 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 fi.helsinki.cs.iot.kahvihub.conf;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

import org.json.JSONException;
import org.json.JSONObject;

/**
 * 
 * @author Julien Mineraud <julien.mineraud@cs.helsinki.fi>
 * ConfigurationFileParser is a JSON parser to generate the HubConfig
 */
public class ConfigurationFileParser {

    private static String getStringProperty(JSONObject root, String name) throws ConfigurationParsingException {
        String val = null;
        try {
            val = root.getString(name);
            if (val == null) {
                throw new ConfigurationParsingException(
                        "The configuration file needs a " + name + " property (string)");
            }
        } catch (JSONException e) {
            throw new ConfigurationParsingException(
                    "The configuration file needs a " + name + " property (string)");
        }
        return val;
    }

    private static int getIntProperty(JSONObject root, String name) throws ConfigurationParsingException {
        int val = -1;
        try {
            val = root.getInt(name);
            if (val == -1) {
                throw new ConfigurationParsingException(
                        "The configuration file needs a " + name + " property (int)");
            }
        } catch (JSONException e) {
            throw new ConfigurationParsingException("The configuration file needs a " + name + " property (int)");
        }
        return val;
    }

    private static boolean getBooleanProperty(JSONObject root, String name) throws ConfigurationParsingException {
        boolean val = false;
        try {
            val = root.getBoolean(name);
        } catch (JSONException e) {
            throw new ConfigurationParsingException(
                    "The configuration file needs a " + name + " property (boolean)");
        }
        return val;
    }

    public static HubConfig parseConfigurationFile(String filename)
            throws ConfigurationParsingException, IOException {
        FileReader fileReader = new FileReader(filename);
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        StringBuilder stringBuilder = new StringBuilder();
        String line = null;
        while ((line = bufferedReader.readLine()) != null) {
            stringBuilder.append(line);
        }
        bufferedReader.close();
        fileReader.close();

        JSONObject root = null;
        try {
            root = new JSONObject(stringBuilder.toString());
        } catch (JSONException e) {
            throw new ConfigurationParsingException("The configuration file is not a proper JSON object");
        }

        String name = getStringProperty(root, "name");
        int port = getIntProperty(root, "port");
        String host = getStringProperty(root, "host");
        String libdir = getStringProperty(root, "libdir");
        String logdir = getStringProperty(root, "logdir");
        String dbdir = getStringProperty(root, "dbdir");
        String dbname = getStringProperty(root, "dbname");
        int dbversion = getIntProperty(root, "dbversion");
        boolean debugMode = getBooleanProperty(root, "debug");

        return new HubConfig(name, host, port, libdir, logdir, dbdir, dbname, dbversion, debugMode);
    }
}