001/**
002 * Copyright (c) 2004-2011 QOS.ch
003 * All rights reserved.
004 *
005 * Permission is hereby granted, free  of charge, to any person obtaining
006 * a  copy  of this  software  and  associated  documentation files  (the
007 * "Software"), to  deal in  the Software without  restriction, including
008 * without limitation  the rights to  use, copy, modify,  merge, publish,
009 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
010 * permit persons to whom the Software  is furnished to do so, subject to
011 * the following conditions:
012 *
013 * The  above  copyright  notice  and  this permission  notice  shall  be
014 * included in all copies or substantial portions of the Software.
015 *
016 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
017 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
018 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
019 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
020 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
021 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
022 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
023 *
024 */
025package org.slf4j.ext;
026
027import org.slf4j.Logger;
028import org.slf4j.Marker;
029import org.slf4j.MarkerFactory;
030import org.slf4j.helpers.FormattingTuple;
031import org.slf4j.helpers.MessageFormatter;
032import org.slf4j.spi.LocationAwareLogger;
033
034/**
035 * A utility that provides standard mechanisms for logging certain kinds of
036 * activities.
037 * 
038 * @author Ralph Goers
039 * @author Ceki Gülcü
040 */
041public class XLogger extends LoggerWrapper implements Logger {
042
043    private static final String FQCN = XLogger.class.getName();
044    static Marker FLOW_MARKER = MarkerFactory.getMarker("FLOW");
045    static Marker ENTRY_MARKER = MarkerFactory.getMarker("ENTRY");
046    static Marker EXIT_MARKER = MarkerFactory.getMarker("EXIT");
047
048    static Marker EXCEPTION_MARKER = MarkerFactory.getMarker("EXCEPTION");
049    static Marker THROWING_MARKER = MarkerFactory.getMarker("THROWING");
050    static Marker CATCHING_MARKER = MarkerFactory.getMarker("CATCHING");
051
052    static String EXIT_MESSAGE_0 = "exit";
053    static String EXIT_MESSAGE_1 = "exit with ({})";
054
055    static String ENTRY_MESSAGE_0 = "entry";
056    static String ENTRY_MESSAGE_1 = "entry with ({})";
057    static String ENTRY_MESSAGE_2 = "entry with ({}, {})";
058    static String ENTRY_MESSAGE_3 = "entry with ({}, {}, {})";
059    static String ENTRY_MESSAGE_4 = "entry with ({}, {}, {}, {})";
060    static int ENTRY_MESSAGE_ARRAY_LEN = 5;
061    static String[] ENTRY_MESSAGE_ARRAY = new String[ENTRY_MESSAGE_ARRAY_LEN];
062    static {
063        ENTRY_MARKER.add(FLOW_MARKER);
064        EXIT_MARKER.add(FLOW_MARKER);
065        THROWING_MARKER.add(EXCEPTION_MARKER);
066        CATCHING_MARKER.add(EXCEPTION_MARKER);
067
068        ENTRY_MESSAGE_ARRAY[0] = ENTRY_MESSAGE_0;
069        ENTRY_MESSAGE_ARRAY[1] = ENTRY_MESSAGE_1;
070        ENTRY_MESSAGE_ARRAY[2] = ENTRY_MESSAGE_2;
071        ENTRY_MESSAGE_ARRAY[3] = ENTRY_MESSAGE_3;
072        ENTRY_MESSAGE_ARRAY[4] = ENTRY_MESSAGE_4;
073    }
074
075    public enum Level {
076        TRACE("TRACE", LocationAwareLogger.TRACE_INT), DEBUG("DEBUG", LocationAwareLogger.DEBUG_INT), INFO("INFO", LocationAwareLogger.INFO_INT), WARN("WARN",
077                        LocationAwareLogger.WARN_INT), ERROR("ERROR", LocationAwareLogger.ERROR_INT);
078
079        private final String name;
080        private final int level;
081
082        public String toString() {
083            return this.name;
084        }
085
086        public int intValue() {
087            return this.level;
088        }
089
090        private Level(String name, int level) {
091            this.name = name;
092            this.level = level;
093        }
094    }
095
096    /**
097     * Given an underlying logger, construct an XLogger
098     * 
099     * @param logger
100     *          underlying logger
101     */
102    public XLogger(Logger logger) {
103        // If class B extends A, assuming B does not override method x(), the caller
104        // of new B().x() is A and not B, see also
105        // http://jira.qos.ch/browse/SLF4J-105
106        super(logger, LoggerWrapper.class.getName());
107    }
108
109    /**
110     * Log method entry.
111     * 
112     * @param argArray
113     *          supplied parameters
114     */
115    public void entry(Object... argArray) {
116        if (instanceofLAL && logger.isTraceEnabled(ENTRY_MARKER)) {
117            String messagePattern = null;
118            if (argArray.length < ENTRY_MESSAGE_ARRAY_LEN) {
119                messagePattern = ENTRY_MESSAGE_ARRAY[argArray.length];
120            } else {
121                messagePattern = buildMessagePattern(argArray.length);
122            }
123            FormattingTuple tp = MessageFormatter.arrayFormat(messagePattern, argArray);
124            ((LocationAwareLogger) logger).log(ENTRY_MARKER, FQCN, LocationAwareLogger.TRACE_INT, tp.getMessage(), argArray, tp.getThrowable());
125        }
126    }
127
128    /**
129     * Log method exit
130     */
131    public void exit() {
132        if (instanceofLAL && logger.isTraceEnabled(ENTRY_MARKER)) {
133            ((LocationAwareLogger) logger).log(EXIT_MARKER, FQCN, LocationAwareLogger.TRACE_INT, EXIT_MESSAGE_0, null, null);
134        }
135    }
136
137    /**
138     * Log method exit
139     * 
140     * @param result
141     *          The result of the method being exited
142     */
143    public <T> T exit(T result) {
144        if (instanceofLAL && logger.isTraceEnabled(ENTRY_MARKER)) {
145            FormattingTuple tp = MessageFormatter.format(EXIT_MESSAGE_1, result);
146            ((LocationAwareLogger) logger).log(EXIT_MARKER, FQCN, LocationAwareLogger.TRACE_INT, tp.getMessage(), new Object[] { result }, tp.getThrowable());
147        }
148        return result;
149    }
150
151    /**
152     * Log an exception being thrown. The generated log event uses Level ERROR.
153     * 
154     * @param throwable
155     *          the exception being caught.
156     */
157    public <T extends Throwable> T throwing(T throwable) {
158        if (instanceofLAL) {
159            ((LocationAwareLogger) logger).log(THROWING_MARKER, FQCN, LocationAwareLogger.ERROR_INT, "throwing", null, throwable);
160        }
161        return throwable;
162    }
163
164    /**
165     * Log an exception being thrown allowing the log level to be specified.
166     * 
167     * @param level
168     *          the logging level to use.
169     * @param throwable
170     *          the exception being caught.
171     */
172    public <T extends Throwable> T throwing(Level level, T throwable) {
173        if (instanceofLAL) {
174            ((LocationAwareLogger) logger).log(THROWING_MARKER, FQCN, level.level, "throwing", null, throwable);
175        }
176        return throwable;
177    }
178
179    /**
180     * Log an exception being caught. The generated log event uses Level ERROR.
181     * 
182     * @param throwable
183     *          the exception being caught.
184     */
185    public void catching(Throwable throwable) {
186        if (instanceofLAL) {
187            ((LocationAwareLogger) logger).log(CATCHING_MARKER, FQCN, LocationAwareLogger.ERROR_INT, "catching", null, throwable);
188        }
189    }
190
191    /**
192     * Log an exception being caught allowing the log level to be specified.
193     * 
194     * @param level
195     *          the logging level to use.
196     * @param throwable
197     *          the exception being caught.
198     */
199    public void catching(Level level, Throwable throwable) {
200        if (instanceofLAL) {
201            ((LocationAwareLogger) logger).log(CATCHING_MARKER, FQCN, level.level, "catching", null, throwable);
202        }
203    }
204
205    private static String buildMessagePattern(int len) {
206        StringBuilder sb = new StringBuilder();
207        sb.append(" entry with (");
208        for (int i = 0; i < len; i++) {
209            sb.append("{}");
210            if (i != len - 1)
211                sb.append(", ");
212        }
213        sb.append(')');
214        return sb.toString();
215    }
216}