001/*
002 * jPOS Project [http://jpos.org]
003 * Copyright (C) 2000-2026 jPOS Software SRL
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
017 */
018
019package org.jpos.util;
020
021import org.jpos.core.Configurable;
022import org.jpos.core.Configuration;
023import org.jpos.core.ConfigurationException;
024import org.jpos.q2.Q2;
025
026import java.util.ArrayList;
027import java.util.Collections;
028import java.util.ConcurrentModificationException;
029import java.util.Iterator;
030import java.util.List;
031
032/**
033 * Peer class Logger forwards LogEvents generated by LogSources 
034 * to LogListeners.
035 * <br>
036 * This little <a href="/doc/LoggerGuide.html">tutorial</a>
037 * give you additional information on how to extend the jPOS's
038 * Logger subsystem.
039 *
040 * @author apr@cs.com.uy
041 * @version $Id$
042 * @see LogEvent
043 * @see LogSource
044 * @see LogListener
045 * @see Loggeable
046 * @see SimpleLogListener
047 * @see RotateLogListener
048 */
049@SuppressWarnings("unchecked")
050public class Logger implements LogProducer,Configurable
051{
052    Configuration cfg;
053    String name;
054    List<LogListener> listeners;
055    public static final String NRPREFIX = "logger.";
056
057    public Logger () {
058        super();
059        listeners = Collections.synchronizedList(new ArrayList<>());
060        name = "";
061    }
062
063    public Configuration getConfiguration()
064    {
065        return cfg;
066    }
067
068    @Override
069    public void setConfiguration(Configuration cfg) throws ConfigurationException
070    {
071        this.cfg = cfg;
072    }
073
074    public void addListener (LogListener l) {
075        listeners.add(l);
076    }
077    public void removeListener (LogListener l) {
078        listeners.remove(l);
079    }
080    public void removeAllListeners () {
081        for (Object l : listeners) {
082            if (l instanceof Destroyable) {
083                ((Destroyable) l).destroy();
084            }
085        }
086        listeners.clear ();
087    }
088    public static void log (LogEvent evt) {
089        Logger l = null;
090        LogSource source = evt.getSource();
091        if (source != null)
092            l = source.getLogger();
093        if (l == null && !evt.isHonorSourceLogger()) {
094            l = getLogger(Q2.LOGGER_NAME);
095        }
096        if (l != null && l.hasListeners ()) {
097            Iterator<LogListener> i = l.listeners.iterator();
098            while (i.hasNext() && evt != null) {
099                try {
100                    evt = i.next().log(evt);
101                } catch (ConcurrentModificationException e) {
102                    break;
103                } catch (Throwable t) {
104                    evt.addMessage (t);
105                }
106            }
107        }
108    }
109    /**
110     * associates this Logger with a name using NameRegistrar
111     * @param name name to register
112     * @see NameRegistrar
113     */
114    public void setName (String name) {
115        this.name = name;
116        NameRegistrar.register (NRPREFIX+name, this);
117    }
118    /**
119     * destroy logger
120     */
121    public void destroy () {
122        NameRegistrar.unregister (NRPREFIX+name);
123        removeAllListeners ();
124    }
125    /**
126     * @return logger instance with given name. Creates one if necessary
127     * @see NameRegistrar
128     */
129    public synchronized static Logger getLogger (String name) {
130        Logger l;
131        try {
132            l = NameRegistrar.get (NRPREFIX+name);
133        } catch (NameRegistrar.NotFoundException e) {
134            l = new Logger();
135            l.setName (name);
136        }
137        return l;
138    }
139    /**
140     * @return this logger's name ("" if no name was set)
141     */
142    public String getName() {
143        return this.name;
144    }
145    /**
146     * Used by heavy used methods to avoid LogEvent creation 
147     * @return true if Logger has associated LogListsners
148     */
149    public boolean hasListeners() {
150        return !listeners.isEmpty();
151    }
152}