UserProperty.java

/* Copyright 2006 VPAC
 * 
 * This file is part of Grix.
 * Grix is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * any later version.

 * Grix 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 General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with Grix; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

package org.vpac.grix.control.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;
import java.util.StringTokenizer;

import org.apache.log4j.Logger;
import org.vpac.common.model.GlobusLocations;

/**
 * This class manages the properties file which is located in the .globus
 * directory. It enables getting and setting of properties. If a property is not
 * set, it returns "no".
 * 
 * @author Markus Binsteiner
 * 
 */
public class UserProperty {

	static final Logger myLogger = Logger.getLogger(UserProperty.class
			.getName());

	private static final File prop_file = new File(GlobusLocations
			.defaultLocations().getGlobusDirectory().getAbsolutePath()
			+ File.separator
			+ GrixProperty.getString("user.properties.filename"));

	private static Properties grix_properties = getGrixProperties();

	private static Properties getGrixProperties() {

		Properties properties = null;

		properties = new Properties();
		try {
			properties.load(new FileInputStream(prop_file));
		} catch (FileNotFoundException fnfe) {
			myLogger.debug("Property file not found. Does not matter, it will be created later on.");
		} catch (IOException ioe) {
			myLogger.debug("Could not read property file. Most likely due to permission issues. Hmm.");
		}

		return properties;
	}

	/**
	 * Appends a value to the end of the list of values for that key (separated
	 * by ",", so "," are not allowed
	 * 
	 * @param key
	 *            the key to which the value is added
	 * @param value
	 *            the value to add
	 * @return true if everything went fine, false if the value already exists
	 */
	public static boolean addToList(String key, String value) {

		// TODO test for ","
		StringTokenizer oldvalues = null;
		try {
			oldvalues = new StringTokenizer(grix_properties.getProperty(key),
					",");
		} catch (NullPointerException npe) {
			setProperty(key, value);
			myLogger.debug("Put \"" + value
					+ "\" in front of the list (only element).");
			return true;
		}
		StringBuffer newvalues = new StringBuffer();
		while (oldvalues.hasMoreTokens()) {
			String oldvalue = oldvalues.nextToken();
			if (oldvalue.equals(value))
				return false;
			newvalues.append(oldvalue + ",");
		}
		newvalues.append(value);
		setProperty(key, newvalues.toString());
		return true;
	}

	public static boolean removeFromList(String key, String value) {
		StringTokenizer oldvalues = null;
		try {
			oldvalues = new StringTokenizer(grix_properties.getProperty(key),
					",");
		} catch (NullPointerException npe) {
			myLogger.debug("Cannot remove element from empty list.");
			return false;
		}

		boolean omitted = false;
		boolean frontposition = true;
		StringBuffer newvalues = new StringBuffer();
		while (oldvalues.hasMoreTokens()) {
			String oldvalue = oldvalues.nextToken();
			if (!oldvalue.equals(value)) {
				if (frontposition) {
					newvalues.append(oldvalue);
					frontposition = false;
				} else
					newvalues.append("," + oldvalue);
			} else
				omitted = true;
		}

		if (omitted) {
			setProperty(key, newvalues.toString());
			return true;
		} else
			return false;

	}

	/**
	 * Checks whether an element is in the according list of the key or not
	 * 
	 * @param key
	 *            the key
	 * @param value
	 *            the element
	 * @return true if element is in list, false if not
	 */
	public static boolean isInList(String key, String value) {
		StringTokenizer values = null;
		try {
			values = new StringTokenizer(grix_properties.getProperty(key), ",");
		} catch (NullPointerException npe) {
			myLogger.debug("Cannot check element in empty list.");
			return false;
		}
		while (values.hasMoreTokens()) {
			if (values.nextToken().equals(value))
				return true;
		}

		return false;
	}

	/**
	 * Get the property for the specified key.
	 * 
	 * @param key
	 *            the key
	 * @return the property, if no property is found, it returns null
	 */
	public static String getProperty(String key) {

		String result = grix_properties.getProperty(key);
		// if ( result == null ) result = "no";

		return result;
	}

	/**
	 * Get the properties in a list as String array
	 * 
	 * @param key
	 *            the key
	 * @return the property as a String array or null
	 */
	public static String[] getPropertyList(String key) {

		String result = getProperty(key);

		if (result != null) {
			return result.split(",");
		}

		return null;
	}

	/**
	 * Sets the property for the specified key
	 * 
	 * @param key
	 *            the key
	 * @param value
	 *            the value (use lowercase if possible)
	 */
	public static void setProperty(String key, String value) {

		grix_properties.setProperty(key, value);

		try {
			if (!GlobusLocations.defaultLocations().globusDirectoryExists()) {
				GlobusLocations.defaultLocations().createGlobusDirectory();
			}
			grix_properties.store(new FileOutputStream(prop_file), null);
		} catch (IOException e) {
			myLogger.error("Can not store properties file. This is pretty serious, so I am exiting. Please check the permissions for the folder: "
					+ GlobusLocations.defaultLocations().getGlobusDirectory()
							.toString());
			System.exit(-1);
		}
	}

	/**
	 * Returns the file in which the properties are stored.
	 * 
	 * @return the prop_file
	 */
	public static File getPropFile() {

		return prop_file;
	}

}