com.halware.nakedide.eclipse.core.logging.LogController.java Source code

Introduction

Here is the source code for com.halware.nakedide.eclipse.core.logging.LogController.java

Source

package com.halware.nakedide.eclipse.core.logging;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.net.SocketAppender;
import org.apache.log4j.varia.NullAppender;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;

import com.halware.nakedide.eclipse.core.Activator;

/**
 * Sets up and controls logging.
 * 
 * <p>
 * Instantiate once and throw away.  It registers itself with the 
 * {@link IPreferenceStore} which will hold a 
 * strong reference to it.  (Does this constitute a memory leak?)
 * 
 * <p>
 * TODO: factor out the common stuff here into IAppenderController (currently empty).
 * 
 * @author Mike
 */
public class LogController implements IPropertyChangeListener {

    /**
     * Constructor starts listening on preference store and sets up initial
     * logging state
     */
    public LogController() {
        IPreferenceStore store = Activator.getDefault().getPreferenceStore();
        store.setDefault(LogController.SOCKET_APPENDER_HOST_NAME_KEY,
                LogController.SOCKET_APPENDER_DEFAULT_HOST_NAME);
        store.setDefault(LogController.SOCKET_APPENDER_PORT_KEY, LogController.SOCKET_APPENDER_DEFAULT_PORT);

        store.addPropertyChangeListener(this);
        boolean appenderAdded = false;

        if (store.getBoolean(LogController.CONSOLE_APPENDER_KEY)) {
            addConsoleAppender();
            appenderAdded = true;
        }
        if (store.getBoolean(LogController.SOCKET_APPENDER_KEY)) {
            addSocketAppender();
            appenderAdded = true;
        }
        if (!appenderAdded) {
            // prevent 'no appender' error messages by log4j
            Logger.getRootLogger().addAppender(new NullAppender());
        }
        setLevel(store.getString(LogController.LEVEL_KEY));
    }

    /**
     * Adds/removes appenders based on changes to preferences
     * @see org.eclipse.core.runtime.Preferences$IPropertyChangeListener#propertyChange(org.eclipse.core.runtime.Preferences.PropertyChangeEvent)
     */
    public void propertyChange(final org.eclipse.jface.util.PropertyChangeEvent event) {

        String eventProperty = event.getProperty();
        Object eventNewValue = event.getNewValue();

        if (LogController.CONSOLE_APPENDER_KEY.equals(eventProperty)) {
            boolean appendToConsole = asBool(eventNewValue);
            if (appendToConsole) {
                if (_consoleAppender == null) {
                    addConsoleAppender();
                }
            } else {
                if (_consoleAppender != null) {
                    removeConsoleAppender();
                }
            }
        }

        if (LogController.SOCKET_APPENDER_KEY.equals(eventProperty)) {
            boolean appendToSocket = asBool(eventNewValue);
            if (appendToSocket) {
                if (_socketAppender == null) {
                    addSocketAppender();
                }
            } else {
                if (_socketAppender != null) {
                    removeSocketAppender();
                }
            }
        }

        if (LogController.LEVEL_KEY.equals(eventProperty)) {
            assert eventNewValue instanceof String;
            setLevel(asString(eventNewValue));
        }
    }

    private boolean asBool(Object eventNewValue) {
        assert eventNewValue instanceof Boolean;
        return ((Boolean) eventNewValue).booleanValue();
    }

    private String asString(Object eventNewValue) {
        assert eventNewValue instanceof Boolean;
        return (String) eventNewValue;
    }

    ///////////////////////////////////////////////////////////////////
    // ConsoleAppender
    ///////////////////////////////////////////////////////////////////

    public static final String CONSOLE_APPENDER_KEY = "LogController.ShowConsole";

    private MessageConsoleAppender _consoleAppender = null;

    private void addConsoleAppender() {
        assert _consoleAppender == null;
        _consoleAppender = new MessageConsoleAppender();
        Logger.getRootLogger().addAppender(_consoleAppender);
    }

    private void removeConsoleAppender() {
        assert _consoleAppender != null;
        _consoleAppender.close();
        Logger.getRootLogger().removeAppender(_consoleAppender);
        _consoleAppender = null;
    }

    ///////////////////////////////////////////////////////////////////
    // SocketAppender
    ///////////////////////////////////////////////////////////////////

    public static final String SOCKET_APPENDER_KEY = "LogController.SocketAppender";
    public static final String SOCKET_APPENDER_HOST_NAME_KEY = "LogController.SocketAppenderHostName";
    public static final String SOCKET_APPENDER_PORT_KEY = "LogController.SocketAppenderPort";

    public static final String SOCKET_APPENDER_DEFAULT_HOST_NAME = "localhost";
    public static final int SOCKET_APPENDER_DEFAULT_PORT = 4445;

    private SocketAppender _socketAppender = null;

    private void addSocketAppender() {
        assert _socketAppender == null;

        IPreferenceStore store = Activator.getDefault().getPreferenceStore();
        String hostname = store.getString(LogController.SOCKET_APPENDER_HOST_NAME_KEY);
        int port = store.getInt(LogController.SOCKET_APPENDER_PORT_KEY);
        Logger.getRootLogger().addAppender(new SocketAppender(hostname, port));

        _socketAppender = new SocketAppender(hostname, port);
        Logger.getRootLogger().addAppender(_socketAppender);
    }

    private void removeSocketAppender() {
        assert _socketAppender != null;
        _socketAppender.close();
        Logger.getRootLogger().removeAppender(_socketAppender);
        _consoleAppender = null;
    }

    ///////////////////////////////////////////////////////////////////
    // Level
    ///////////////////////////////////////////////////////////////////

    public static final String LEVEL_KEY = "LogController.Level";

    private void setLevel(String levelStr) {
        Level level = Level.toLevel(levelStr);
        Logger.getRootLogger().setLevel(level);
    }

}

/******************************************************************************
 * (c) 2007 Haywood Associates Ltd.
 * 
 * Distributed under Eclipse Public License 1.0, see
 * http://www.eclipse.org/legal/epl-v10.html for full details.
 *
 * In particular:
 * THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR 
 * CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT 
 * LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, 
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * If you require this software under any other type of license, then contact 
 * Dan Haywood through http://www.haywood-associates.co.uk.
 *
 *****************************************************************************/