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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 G&uuml;lc&uuml;
    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://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 }