org.accada.hal.ControllerProperties.java Source code

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Here is the source code for org.accada.hal.ControllerProperties.java

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/*
 * Copyright (C) 2007 ETH Zurich
 *
 * This file is part of Accada (www.accada.org).
 *
 * Accada is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software Foundation.
 *
 * Accada is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Accada; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

package org.accada.hal;

import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;

import org.accada.hal.util.ResourceLocator;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.XMLConfiguration;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * The <code>ControllerProperties</code> class encapsulates the methods responsible for
 * the parameter setting. It can be seen as a helper class that frees the user from implementing
 * the related methods and function calls in his concrete <code>AutoIdController</code> imlementation.
 * As a convention the properties file associated with a certain reader has to be named according to its
 * class name.
 * 
 * @version 19.01.2004
 * @author Stefan Schlegel (schlstef@student.ethz.ch)
 * 
 * Modified 06.10.2004 (Roland Schneider schnerol):
 * Instead of using the class name to locate the properties file newly the reader ID defines
 * the properties file name. see new constructor. 
 * 
 */

public class ControllerProperties {

    //-------------------------------------------fields------------------------------------------//
    /** the logger */
    static private Log log = LogFactory.getLog(ControllerProperties.class);
    /** the name of the configuration file */
    private String configFile = null;
    private String defaultConfigFile = null;
    /** the configuration */
    private XMLConfiguration conf = null;

    //-------------------------------------------constructors--------------------------------------//   

    public ControllerProperties(String configFile, String defaultConfigFile) {
        this.configFile = configFile;
        this.defaultConfigFile = defaultConfigFile;
        log.debug("PropertiesFile: " + configFile + " and " + defaultConfigFile);

    }

    //---------------------------------------------methods--------------------------------------------//   

    /**
     * Gets the parameter with the specified name from the appropriate properties file.
     * 
     * @param param parameter name.
     * @return the value of the parameter or null if parameter not available.
     * @throws Exception.
     */
    public String getParameter(String param) throws Exception {
        String value = null;
        if (conf == null) {
            loadConfig();
        }
        log.debug("Trying to get Parameter " + param);
        value = conf.getString(param, null);
        if (value != null) {
            log.debug("Property found: " + param + " = " + value);
        } else {
            log.debug("Property '" + param + "' not found, returning null.");
        }
        return value;
    }

    /**
     * Sets the specified parameter.
     * 
     * @param param The parameter that has to be set.
     * @param value The new value for the parameter.
     */
    public void setParameter(String param, String value) {
        /* Mit dieser Implemetation wurden alle Kommentare im File berschrieben.
         * Properties file has changed from java properties to xml!
             
        Properties propertyFile = new Properties();
        InputStream input = null;
        OutputStream output = null;
            
        try{
           input = new FileInputStream("./props/"+propsFile);
           propertyFile.load(input);
           input.close();
           if (propertyFile.containsKey(param)){
        output = new FileOutputStream("./props/"+propsFile);
        propertyFile.setProperty(param,value);
        propertyFile.store(output,null);
        output.close();
           }
           else {
        String message ="Unkown Parameter: "+ param + ". Value: "+value+ " not set." 
        log.debug(message);
        throw new Exception(message);
           }
        }catch(IOException ex){
           ex.printStackTrace();
           throw new Exception(ex.getMessage());
        }
        */
    }

    /**
     * Gets the names of the configurable parameters.
     * 
     * @return The parameter names.
     * 
     * @throws Exception
     */
    public String[] getParameterNames() throws Exception {
        String[] names = new String[] { "" };

        if (conf == null) {
            loadConfig();
        }
        log.debug("Trying to get Parameters");
        Iterator keyiterator = conf.getKeys();
        ArrayList<String> arraylist = new ArrayList<String>();
        String element = null;
        Object object = null;
        Class stringclass = Class.forName("java.lang.String");
        while (keyiterator.hasNext()) {
            object = keyiterator.next();
            if (stringclass.isInstance(object)) {
                element = (String) object;
                arraylist.add(element);
            }
        }
        names = arraylist.toArray(names);

        return names;
    }

    /**
     * Loads the configuration file
     * 
     * @param propFile The name of the configuration file
     * @throws IOException
     */
    private void loadConfig() throws IOException {
        conf = new XMLConfiguration();
        URL url = ResourceLocator.getURL(configFile, defaultConfigFile, this.getClass());
        try {
            conf.load(url);
        } catch (ConfigurationException e) {
            log.error("Could not find properties file: " + configFile);
            throw new IOException("Properties file not found.");
        }
    }
}