001    /* ========================================================================
002     * JCommon : a free general purpose class library for the Java(tm) platform
003     * ========================================================================
004     *
005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006     * 
007     * Project Info:  http://www.jfree.org/jcommon/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it 
010     * under the terms of the GNU Lesser General Public License as published by 
011     * the Free Software Foundation; either version 2.1 of the License, or 
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but 
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022     * USA.  
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     * 
027     * ---------------
028     * LogContext.java
029     * ---------------
030     * (C)opyright 2004, by Thomas Morgner and Contributors.
031     *
032     * Original Author:  Thomas Morgner;
033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
034     *
035     * $Id: LogContext.java,v 1.3 2005/10/18 13:24:19 mungady Exp $
036     *
037     * Changes 
038     * -------
039     * 26-Apr-2004 : Initial version (TM);
040     *  
041     */
042    
043    package org.jfree.util;
044    
045    /**
046     * A log context.
047     *
048     * @author Thomas Morgner
049     */
050    public class LogContext {
051    
052        /** The prefix string. */
053        private String contextPrefix;
054    
055        /**
056         * Creates a new log context.
057         * 
058         * @param contextPrefix  the prefix.
059         */
060        public LogContext(final String contextPrefix) {
061            this.contextPrefix = contextPrefix;
062        }
063    
064        /**
065         * Returns true, if the log level allows debug messages to be
066         * printed.
067         *
068         * @return true, if messages with an log level of DEBUG are allowed.
069         */
070        public boolean isDebugEnabled() {
071            return Log.isDebugEnabled();
072        }
073    
074        /**
075         * Returns true, if the log level allows informational
076         * messages to be printed.
077         *
078         * @return true, if messages with an log level of INFO are allowed.
079         */
080        public boolean isInfoEnabled() {
081            return Log.isInfoEnabled();
082        }
083    
084        /**
085         * Returns true, if the log level allows warning messages to be
086         * printed.
087         *
088         * @return true, if messages with an log level of WARN are allowed.
089         */
090        public boolean isWarningEnabled() {
091            return Log.isWarningEnabled();
092        }
093    
094        /**
095         * Returns true, if the log level allows error messages to be
096         * printed.
097         *
098         * @return true, if messages with an log level of ERROR are allowed.
099         */
100        public boolean isErrorEnabled() {
101            return Log.isErrorEnabled();
102        }
103    
104    
105        /**
106         * A convenience method for logging a 'debug' message.
107         *
108         * @param message the message.
109         */
110        public void debug(final Object message) {
111            log(LogTarget.DEBUG, message);
112        }
113    
114        /**
115         * A convenience method for logging a 'debug' message.
116         *
117         * @param message the message.
118         * @param e       the exception.
119         */
120        public void debug(final Object message, final Exception e) {
121            log(LogTarget.DEBUG, message, e);
122        }
123    
124        /**
125         * A convenience method for logging an 'info' message.
126         *
127         * @param message the message.
128         */
129        public void info(final Object message) {
130            log(LogTarget.INFO, message);
131        }
132    
133        /**
134         * A convenience method for logging an 'info' message.
135         *
136         * @param message the message.
137         * @param e       the exception.
138         */
139        public void info(final Object message, final Exception e) {
140            log(LogTarget.INFO, message, e);
141        }
142    
143        /**
144         * A convenience method for logging a 'warning' message.
145         *
146         * @param message the message.
147         */
148        public void warn(final Object message) {
149            log(LogTarget.WARN, message);
150        }
151    
152        /**
153         * A convenience method for logging a 'warning' message.
154         *
155         * @param message the message.
156         * @param e       the exception.
157         */
158        public void warn(final Object message, final Exception e) {
159            log(LogTarget.WARN, message, e);
160        }
161    
162        /**
163         * A convenience method for logging an 'error' message.
164         *
165         * @param message the message.
166         */
167        public void error(final Object message) {
168            log(LogTarget.ERROR, message);
169        }
170    
171        /**
172         * A convenience method for logging an 'error' message.
173         *
174         * @param message the message.
175         * @param e       the exception.
176         */
177        public void error(final Object message, final Exception e) {
178            log(LogTarget.ERROR, message, e);
179        }
180    
181        /**
182         * Logs a message to the main log stream.  All attached log targets will also
183         * receive this message. If the given log-level is higher than the given debug-level
184         * in the main config file, no logging will be done.
185         *
186         * @param level   log level of the message.
187         * @param message text to be logged.
188         */
189        public void log(final int level, final Object message) {
190            if (this.contextPrefix != null) {
191                Log.getInstance().doLog(level, new Log.SimpleMessage(this.contextPrefix, ":", message));
192            }
193            else {
194                Log.getInstance().doLog(level, message);
195            }
196        }
197    
198        /**
199         * Logs a message to the main log stream. All attached logTargets will also
200         * receive this message. If the given log-level is higher than the given debug-level
201         * in the main config file, no logging will be done.
202         * <p/>
203         * The exception's stacktrace will be appended to the log-stream
204         *
205         * @param level   log level of the message.
206         * @param message text to be logged.
207         * @param e       the exception, which should be logged.
208         */
209        public void log(final int level, final Object message, final Exception e) {
210            if (this.contextPrefix != null) {
211                Log.getInstance().doLog(
212                    level, new Log.SimpleMessage(this.contextPrefix, ":", message), e
213                );
214            }
215            else {
216                Log.getInstance().doLog(level, message, e);
217            }
218        }
219    
220        /**
221         * Tests this object for equality with an arbitrary object.
222         * 
223         * @param o  the object to test against (<code>null</code> permitted).
224         * 
225         * @return A boolean.
226         */
227        public boolean equals(final Object o) {
228            if (this == o) {
229                return true;
230            }
231            if (!(o instanceof LogContext)) {
232                return false;
233            }
234    
235            final LogContext logContext = (LogContext) o;
236    
237            if (this.contextPrefix != null)
238            {
239                if (!this.contextPrefix.equals(logContext.contextPrefix)) {
240                    return false;
241                }
242            }
243            else {
244                if (logContext.contextPrefix != null) {
245                    return false;
246                }
247            }
248    
249            return true;
250        }
251    
252        /**
253         * Returns a hashcode.
254         * 
255         * @return The hashcode.
256         */
257        public int hashCode() {
258            return (this.contextPrefix != null ? this.contextPrefix.hashCode() : 0);
259        }
260    }