edu.wright.daselab.linkgen.ConfigurationLoader.java Source code

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Here is the source code for edu.wright.daselab.linkgen.ConfigurationLoader.java

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/**
 * 
 * @author Amit Joshi, github.com/akjoshi
 * Data Semantics Lab, Wright State University, Dayton, Ohio, US
 * Copyright (c) 2016
 * License GPL
 * If you use this software, please use following citation:
 * Joshi, A.K., Hitzler, P., Dong, G.: Multi-purpose Synthetic Linked Data Generator https://bitbucket.org/akjoshi/linked-data-generator/
 * Web Id for the resource: http://w3id.org/linkgen
 */
package edu.wright.daselab.linkgen;

import java.io.File;
import java.io.FileNotFoundException;
import java.net.URISyntaxException;

import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.jena.tdb.base.file.FileException;

public final class ConfigurationLoader {
    //this class should only use System.err and no logger/Monitor
    private static ConfigurationLoader _instance = null;

    private static final String DEFAULT_CONFIG_FILE_LOCATION = "config.properties";
    public static String CONFIG_FILE_LOCATION = DEFAULT_CONFIG_FILE_LOCATION;

    // make sure that no more than one instance is instantiated.
    public synchronized static ConfigurationLoader getInstance() {
        if (_instance == null)
            _instance = new ConfigurationLoader();
        return _instance;
    }

    public final Configuration getConfig(String filePath) throws FileException {
        //at this point, we haven't loaded the path of log4j.properties file, so ignore any logger errors.
        org.apache.log4j.Logger.getRootLogger().setLevel(org.apache.log4j.Level.OFF);
        Configuration config = null;
        String message = "";
        try {
            File configFile = new File(filePath); // outside the jar file
            if (!configFile.exists()) {
                message = ErrorCodes.Error.CONFIG_FILE_NOT_EXISTS.toString() + "FAILED - " + configFile;
                Monitor.error(message);
                throw new FileNotFoundException(message);
            }
            config = new PropertiesConfiguration(configFile);
            if (config.isEmpty()) {
                message = ErrorCodes.Error.CONFIG_FILE_EMPTY.toString();
                Monitor.error(message);
                throw new FileException(message);
            }
        } catch (Exception e) {
            message = ErrorCodes.Error.CONFIG_FILE_LOAD_ERROR.toString();
            Monitor.error(message);
            throw new FileException(message);
        }
        return (Configuration) config;
    }

    public final Configuration getConfig() throws FileException {
        if (!DEFAULT_CONFIG_FILE_LOCATION.equals(CONFIG_FILE_LOCATION)) {
            return getConfig(CONFIG_FILE_LOCATION);
        }

        File configFile = null;
        File base;
        try {
            base = new File(this.getClass().getProtectionDomain().getCodeSource().getLocation().toURI())
                    .getParentFile();
        } catch (URISyntaxException e) {
            throw new FileException(ErrorCodes.Error.CONFIG_FILE_LOAD_ERROR.toString());
        }
        configFile = new File(base, DEFAULT_CONFIG_FILE_LOCATION);
        return getConfig(configFile.getAbsolutePath());
    }

}