001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software GmbH & Co. KG, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.main;
029
030import java.io.File;
031import java.io.IOException;
032import java.io.InterruptedIOException;
033import java.io.LineNumberReader;
034import java.io.PrintWriter;
035import java.io.StringReader;
036import java.io.StringWriter;
037import java.net.URL;
038import java.net.URLDecoder;
039import java.nio.charset.Charset;
040import java.util.ArrayList;
041
042import org.apache.commons.logging.Log;
043import org.apache.commons.logging.LogFactory;
044import org.apache.logging.log4j.core.config.ConfigurationSource;
045import org.apache.logging.log4j.core.config.Configurator;
046import org.apache.logging.log4j.core.util.Loader;
047
048/**
049 * Provides the OpenCms logging mechanism.<p>
050 *
051 * The OpenCms logging mechanism is based on Apache Commons Logging.
052 * However, log4j is shipped with OpenCms and assumed to be used as default logging mechanism.
053 * Since apparently Commons Logging may cause issues in more complex classloader scenarios,
054 * we may switch the logging interface to log4j <code>UGLI</code> once the final release is available.<p>
055 *
056 * The log4j configuration file shipped with OpenCms is located
057 * in <code>${opencms.WEB-INF}/classes/log4j2.xml</code>. OpenCms will auto-configure itself
058 * to write it's log file to <code>${opencms.WEB-INF}/logs/opencms.log</code>. This default behaviour
059 * can be supressed by either using a log4j configuration file from another location, or by setting the
060 * special property <code>${opencms.set.logfile}</code> in the log4j configuration file to <code>false</code>.
061 *
062 * @since 6.0.0
063 */
064public final class CmsLog {
065
066    /** The name of the opencms.log file. */
067    public static final String FILE_LOG = "opencms.log";
068
069    /** Path to the "logs" folder relative to the "WEB-INF" directory of the application. */
070    public static final String FOLDER_LOGS = "logs" + File.separatorChar;
071
072    /** Log for initialization messages. */
073    public static Log INIT;
074
075    /** The absolute path to the folder of the main OpenCms log file (in the "real" file system). */
076    private static String m_logFileRfsFolder;
077
078    /** The absolute path to the OpenCms log file (in the "real" file system). */
079    private static String m_logFileRfsPath;
080
081    /**
082     * Initializes the OpenCms logger configuration.<p>
083     */
084    static {
085        //
086        // DO NOT USE ANY OPENCMS CLASSES THAT USE STATIC LOGGER INSTANCES IN THIS STATIC BLOCK
087        // OTHERWISE THEIR LOGGER WOULD NOT BE INITIALIZED PROPERLY
088        //
089        try {
090            // look for the log4j2.xml that shipped with OpenCms
091            URL url = Loader.getResource("log4j2.xml", null);
092            if (url != null) {
093                // found some log4j properties, let's see if these are the ones used by OpenCms
094                File log4jProps = new File(URLDecoder.decode(url.getPath(), Charset.defaultCharset().name()));
095                String path = log4jProps.getAbsolutePath();
096                // in a default OpenCms configuration, the following path would point to the OpenCms "WEB-INF" folder
097                String webInfPath = log4jProps.getParent();
098                webInfPath = webInfPath.substring(0, webInfPath.lastIndexOf(File.separatorChar) + 1);
099
100                // check for the OpenCms configuration file
101                // check for the OpenCms tld file
102                String tldFilePath = webInfPath + CmsSystemInfo.FILE_TLD;
103                File tldFile = new File(tldFilePath);
104                if (tldFile.exists()) {
105                    // check if OpenCms should set the log file environment variable
106                    boolean setLogFile = Boolean.parseBoolean(System.getProperty("opencms.set.logfile", "true"));
107                    if (setLogFile) {
108                        // set "opencms.log" variable
109                        String logFilePath = webInfPath + FOLDER_LOGS + FILE_LOG;
110                        File logFile = new File(logFilePath);
111                        m_logFileRfsPath = logFile.getAbsolutePath();
112                        m_logFileRfsFolder = logFile.getParent() + File.separatorChar;
113                        System.setProperty("opencms.logfile", m_logFileRfsPath);
114                        System.setProperty("opencms.logfolder", m_logFileRfsFolder);
115                        // re-read the configuration with the new environment variable available
116                        ConfigurationSource source = ConfigurationSource.fromUri(
117                            Loader.getResource("log4j2.xml", null).toURI());
118                        Configurator.initialize(null, source);
119                    }
120                }
121                // can't localize this message since this would end in an endless logger init loop
122                INIT = LogFactory.getLog("org.opencms.init");
123                INIT.info(". Log4j config file    : " + path);
124            }
125        } catch (SecurityException e) {
126            // may be caused if environment can't be written
127            e.printStackTrace(System.err);
128        } catch (Exception e) {
129            // unexpected but nothing we can do about it, print stack trace and continue
130            e.printStackTrace(System.err);
131        }
132    }
133
134    /**
135     * Hides the public constructor.<p>
136     */
137    private CmsLog() {
138
139        // hides the public constructor
140    }
141
142    /**
143     * Returns the log for the selected object.<p>
144     *
145     * If the provided object is a String, this String will
146     * be used as channel name. Otherwise the objects
147     * class name will be used as channel name.<p>
148     *
149     * @param obj the object channel to use
150     * @return the log for the selected object channel
151     */
152    public static Log getLog(Object obj) {
153
154        if (obj instanceof String) {
155            return LogFactory.getLog((String)obj);
156        } else if (obj instanceof Class<?>) {
157            return LogFactory.getLog((Class<?>)obj);
158        } else {
159            return LogFactory.getLog(obj.getClass());
160        }
161    }
162
163    /**
164     * Render throwable using Throwable.printStackTrace.
165     * <p>This code copy from "org.apache.log4j.DefaultThrowableRenderer.render(Throwable throwable)"</p>
166     * @param throwable throwable, may not be null.
167     * @return string representation.
168     */
169    public static String[] render(final Throwable throwable) {
170
171        StringWriter sw = new StringWriter();
172        PrintWriter pw = new PrintWriter(sw);
173        try {
174            throwable.printStackTrace(pw);
175        } catch (RuntimeException ex) {
176            // nothing to do
177        }
178        pw.flush();
179        LineNumberReader reader = new LineNumberReader(new StringReader(sw.toString()));
180        ArrayList<String> lines = new ArrayList<>();
181        try {
182            String line = reader.readLine();
183            while (line != null) {
184                lines.add(line);
185                line = reader.readLine();
186            }
187        } catch (IOException ex) {
188            if (ex instanceof InterruptedIOException) {
189                Thread.currentThread().interrupt();
190            }
191            lines.add(ex.toString());
192        }
193        //String[] tempRep = new String[lines.size()];
194        return lines.toArray(new String[0]);
195    }
196
197    /**
198     * Returns the filename of the log file (in the "real" file system).<p>
199     *
200     * If the method returns <code>null</code>, this means that the log
201     * file is not managed by OpenCms.<p>
202     *
203     * @return the filename of the log file (in the "real" file system)
204     */
205    protected static String getLogFileRfsPath() {
206
207        return m_logFileRfsPath;
208    }
209}