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      1 /**
      2  * Copyright (c) 2004-2011 QOS.ch
      3  * All rights reserved.
      4  *
      5  * Permission is hereby granted, free  of charge, to any person obtaining
      6  * a  copy  of this  software  and  associated  documentation files  (the
      7  * "Software"), to  deal in  the Software without  restriction, including
      8  * without limitation  the rights to  use, copy, modify,  merge, publish,
      9  * distribute,  sublicense, and/or sell  copies of  the Software,  and to
     10  * permit persons to whom the Software  is furnished to do so, subject to
     11  * the following conditions:
     12  *
     13  * The  above  copyright  notice  and  this permission  notice  shall  be
     14  * included in all copies or substantial portions of the Software.
     15  *
     16  * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
     17  * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
     18  * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
     19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     21  * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
     22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     23  *
     24  */
     25 package org.slf4j.ext;
     26 
     27 import org.slf4j.Logger;
     28 import org.slf4j.Marker;
     29 import org.slf4j.MarkerFactory;
     30 import org.slf4j.helpers.FormattingTuple;
     31 import org.slf4j.helpers.MessageFormatter;
     32 import org.slf4j.spi.LocationAwareLogger;
     33 
     34 /**
     35  * A utility that provides standard mechanisms for logging certain kinds of
     36  * activities.
     37  *
     38  * @author Ralph Goers
     39  * @author Ceki Gülcü
     40  */
     41 public class XLogger extends LoggerWrapper implements Logger {
     42 
     43     private static final String FQCN = XLogger.class.getName();
     44     static Marker FLOW_MARKER = MarkerFactory.getMarker("FLOW");
     45     static Marker ENTRY_MARKER = MarkerFactory.getMarker("ENTRY");
     46     static Marker EXIT_MARKER = MarkerFactory.getMarker("EXIT");
     47 
     48     static Marker EXCEPTION_MARKER = MarkerFactory.getMarker("EXCEPTION");
     49     static Marker THROWING_MARKER = MarkerFactory.getMarker("THROWING");
     50     static Marker CATCHING_MARKER = MarkerFactory.getMarker("CATCHING");
     51 
     52     static String EXIT_MESSAGE_0 = "exit";
     53     static String EXIT_MESSAGE_1 = "exit with ({})";
     54 
     55     static String ENTRY_MESSAGE_0 = "entry";
     56     static String ENTRY_MESSAGE_1 = "entry with ({})";
     57     static String ENTRY_MESSAGE_2 = "entry with ({}, {})";
     58     static String ENTRY_MESSAGE_3 = "entry with ({}, {}, {})";
     59     static String ENTRY_MESSAGE_4 = "entry with ({}, {}, {}, {})";
     60     static int ENTRY_MESSAGE_ARRAY_LEN = 5;
     61     static String[] ENTRY_MESSAGE_ARRAY = new String[ENTRY_MESSAGE_ARRAY_LEN];
     62     static {
     63         ENTRY_MARKER.add(FLOW_MARKER);
     64         EXIT_MARKER.add(FLOW_MARKER);
     65         THROWING_MARKER.add(EXCEPTION_MARKER);
     66         CATCHING_MARKER.add(EXCEPTION_MARKER);
     67 
     68         ENTRY_MESSAGE_ARRAY[0] = ENTRY_MESSAGE_0;
     69         ENTRY_MESSAGE_ARRAY[1] = ENTRY_MESSAGE_1;
     70         ENTRY_MESSAGE_ARRAY[2] = ENTRY_MESSAGE_2;
     71         ENTRY_MESSAGE_ARRAY[3] = ENTRY_MESSAGE_3;
     72         ENTRY_MESSAGE_ARRAY[4] = ENTRY_MESSAGE_4;
     73     }
     74 
     75     public enum Level {
     76         TRACE("TRACE", LocationAwareLogger.TRACE_INT), DEBUG("DEBUG", LocationAwareLogger.DEBUG_INT), INFO("INFO", LocationAwareLogger.INFO_INT), WARN("WARN",
     77                         LocationAwareLogger.WARN_INT), ERROR("ERROR", LocationAwareLogger.ERROR_INT);
     78 
     79         private final String name;
     80         private final int level;
     81 
     82         public String toString() {
     83             return this.name;
     84         }
     85 
     86         public int intValue() {
     87             return this.level;
     88         }
     89 
     90         private Level(String name, int level) {
     91             this.name = name;
     92             this.level = level;
     93         }
     94     }
     95 
     96     /**
     97      * Given an underlying logger, construct an XLogger
     98      *
     99      * @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://bugzilla.slf4j.org/show_bug.cgi?id=114
    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 }
    217