    001/*
    002 * Copyright 2001-2004 The Apache Software Foundation.
    003 *
    004 * Licensed under the Apache License, Version 2.0 (the "License");
    005 * you may not use this file except in compliance with the License.
    006 * You may obtain a copy of the License at
    007 *
    008 *      http://www.apache.org/licenses/LICENSE-2.0
    009 *
    010 * Unless required by applicable law or agreed to in writing, software
    011 * distributed under the License is distributed on an "AS IS" BASIS,
    012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    013 * See the License for the specific language governing permissions and
    014 * limitations under the License.
    015 */
    016
    017package org.apache.commons.logging.impl;
    018
    019import java.io.InputStream;
    020import java.io.Serializable;
    021import java.lang.reflect.InvocationTargetException;
    022import java.lang.reflect.Method;
    023import java.security.AccessController;
    024import java.security.PrivilegedAction;
    025import java.text.DateFormat;
    026import java.text.SimpleDateFormat;
    027import java.util.Date;
    028import java.util.Properties;
    029
    030import org.apache.commons.logging.Log;
    031import org.apache.commons.logging.LogConfigurationException;
    032
    033/**
    034 * <p>
    035 * Simple implementation of Log that sends all enabled log messages, for all
    036 * defined loggers, to System.err. The following system properties are supported
    037 * to configure the behavior of this logger:
    038 * </p>
    039 * <ul>
    040 * <li><code>org.apache.commons.logging.simplelog.defaultlog</code> - Default
    041 * logging detail level for all instances of SimpleLog. Must be one of ("trace",
    042 * "debug", "info", "warn", "error", or "fatal"). If not specified, defaults to
    043 * "info".</li>
    044 * <li><code>org.apache.commons.logging.simplelog.log.xxxxx</code> - Logging
    045 * detail level for a SimpleLog instance named "xxxxx". Must be one of ("trace",
    046 * "debug", "info", "warn", "error", or "fatal"). If not specified, the default
    047 * logging detail level is used.</li>
    048 * <li><code>org.apache.commons.logging.simplelog.showlogname</code> - Set to
    049 * <code>true</code> if you want the Log instance name to be included in output
    050 * messages. Defaults to <code>false</code>.</li>
    051 * <li><code>org.apache.commons.logging.simplelog.showShortLogname</code> - Set
    052 * to <code>true</code> if you want the last component of the name to be
    053 * included in output messages. Defaults to <code>true</code>.</li>
    054 * <li><code>org.apache.commons.logging.simplelog.showdatetime</code> - Set to
    055 * <code>true</code> if you want the current date and time to be included in
    056 * output messages. Default is <code>false</code>.</li>
    057 * <li><code>org.apache.commons.logging.simplelog.dateTimeFormat</code> - The
    058 * date and time format to be used in the output messages. The pattern
    059 * describing the date and time format is the same that is used in
    060 * <code>java.text.SimpleDateFormat</code>. If the format is not specified or is
    061 * invalid, the default format is used. The default format is
    062 * <code>yyyy/MM/dd HH:mm:ss:SSS zzz</code>.</li>
    063 * </ul>
    064 *
    065 * <p>
    066 * In addition to looking for system properties with the names specified above,
    067 * this implementation also checks for a class loader resource named
    068 * <code>"simplelog.properties"</code>, and includes any matching definitions
    069 * from this resource (if it exists).
    070 * </p>
    071 *
    072 * @author <a href="mailto:sanders@apache.org">Scott Sanders</a>
    073 * @author Rod Waldhoff
    074 * @author Robert Burrell Donkin
    075 *
    076 * @version $Id: SimpleLog.java,v 1.21 2004/06/06 20:47:56 rdonkin Exp $
    077 */
    078public class SimpleLog implements Log, Serializable {
    079
    080    private static final long serialVersionUID = 136942970684951178L;
    081
    082    // ------------------------------------------------------- Class Attributes
    083
    084    /** All system properties used by <code>SimpleLog</code> start with this */
    085    static protected final String systemPrefix = "org.apache.commons.logging.simplelog.";
    086
    087    /** Properties loaded from simplelog.properties */
    088    static protected final Properties simpleLogProps = new Properties();
    089
    090    /** The default format to use when formatting dates */
    091    static protected final String DEFAULT_DATE_TIME_FORMAT = "yyyy/MM/dd HH:mm:ss:SSS zzz";
    092
    093    /** Include the instance name in the log message? */
    094    static protected boolean showLogName = false;
    095    /**
    096     * Include the short name ( last component ) of the logger in the log message.
    097     * Defaults to true - otherwise we'll be lost in a flood of messages without
    098     * knowing who sends them.
    099     */
    100    static protected boolean showShortName = true;
    101    /** Include the current time in the log message */
    102    static protected boolean showDateTime = false;
    103    /** The date and time format to use in the log message */
    104    static protected String dateTimeFormat = DEFAULT_DATE_TIME_FORMAT;
    105    /** Used to format times */
    106    static protected DateFormat dateFormatter = null;
    107
    108    // ---------------------------------------------------- Log Level Constants
    109
    110    /** "Trace" level logging. */
    111    public static final int LOG_LEVEL_TRACE = 1;
    112    /** "Debug" level logging. */
    113    public static final int LOG_LEVEL_DEBUG = 2;
    114    /** "Info" level logging. */
    115    public static final int LOG_LEVEL_INFO = 3;
    116    /** "Warn" level logging. */
    117    public static final int LOG_LEVEL_WARN = 4;
    118    /** "Error" level logging. */
    119    public static final int LOG_LEVEL_ERROR = 5;
    120    /** "Fatal" level logging. */
    121    public static final int LOG_LEVEL_FATAL = 6;
    122
    123    /** Enable all logging levels */
    124    public static final int LOG_LEVEL_ALL = (LOG_LEVEL_TRACE - 1);
    125
    126    /** Enable no logging levels */
    127    public static final int LOG_LEVEL_OFF = (LOG_LEVEL_FATAL + 1);
    128
    129    // ------------------------------------------------------------ Initializer
    130
    131    private static String getStringProperty(String name) {
    132        String prop = null;
    133        try {
    134            prop = System.getProperty(name);
    135        } catch (SecurityException e) {
    136            ; // Ignore
    137        }
    138        return (prop == null) ? simpleLogProps.getProperty(name) : prop;
    139    }
    140
    141    private static String getStringProperty(String name, String dephault) {
    142        String prop = getStringProperty(name);
    143        return (prop == null) ? dephault : prop;
    144    }
    145
    146    private static boolean getBooleanProperty(String name, boolean dephault) {
    147        String prop = getStringProperty(name);
    148        return (prop == null) ? dephault : "true".equalsIgnoreCase(prop);
    149    }
    150
    151    // Initialize class attributes.
    152    // Load properties file, if found.
    153    // Override with system properties.
    154    static {
    155        // Add props from the resource simplelog.properties
    156        InputStream in = getResourceAsStream("simplelog.properties");
    157        if (null != in) {
    158            try {
    159                simpleLogProps.load(in);
    160            } catch (java.io.IOException e) {
    161                // ignored
    162            } finally {
    163                try {
    164                    in.close();
    165                } catch (java.io.IOException e) {
    166                    // ignored
    167                }
    168            }
    169        }
    170
    171        showLogName = getBooleanProperty(systemPrefix + "showlogname", showLogName);
    172        showShortName = getBooleanProperty(systemPrefix + "showShortLogname", showShortName);
    173        showDateTime = getBooleanProperty(systemPrefix + "showdatetime", showDateTime);
    174
    175        if (showDateTime) {
    176            dateTimeFormat = getStringProperty(systemPrefix + "dateTimeFormat", dateTimeFormat);
    177            try {
    178                dateFormatter = new SimpleDateFormat(dateTimeFormat);
    179            } catch (IllegalArgumentException e) {
    180                // If the format pattern is invalid - use the default format
    181                dateTimeFormat = DEFAULT_DATE_TIME_FORMAT;
    182                dateFormatter = new SimpleDateFormat(dateTimeFormat);
    183            }
    184        }
    185    }
    186
    187    // ------------------------------------------------------------- Attributes
    188
    189    /** The name of this simple log instance */
    190    protected String logName = null;
    191    /** The current log level */
    192    protected int currentLogLevel;
    193    /** The short name of this simple log instance */
    194    private String shortLogName = null;
    195
    196    // ------------------------------------------------------------ Constructor
    197
    198    /**
    199     * Construct a simple log with given name.
    200     *
    201     * @param name
    202     *          log name
    203     */
    204    public SimpleLog(String name) {
    205
    206        logName = name;
    207
    208        // Set initial log level
    209        // Used to be: set default log level to ERROR
    210        // IMHO it should be lower, but at least info ( costin ).
    211        setLevel(SimpleLog.LOG_LEVEL_INFO);
    212
    213        // Set log level from properties
    214        String lvl = getStringProperty(systemPrefix + "log." + logName);
    215        int i = String.valueOf(name).lastIndexOf(".");
    216        while (null == lvl && i > -1) {
    217            name = name.substring(0, i);
    218            lvl = getStringProperty(systemPrefix + "log." + name);
    219            i = String.valueOf(name).lastIndexOf(".");
    220        }
    221
    222        if (null == lvl) {
    223            lvl = getStringProperty(systemPrefix + "defaultlog");
    224        }
    225
    226        if ("all".equalsIgnoreCase(lvl)) {
    227            setLevel(SimpleLog.LOG_LEVEL_ALL);
    228        } else if ("trace".equalsIgnoreCase(lvl)) {
    229            setLevel(SimpleLog.LOG_LEVEL_TRACE);
    230        } else if ("debug".equalsIgnoreCase(lvl)) {
    231            setLevel(SimpleLog.LOG_LEVEL_DEBUG);
    232        } else if ("info".equalsIgnoreCase(lvl)) {
    233            setLevel(SimpleLog.LOG_LEVEL_INFO);
    234        } else if ("warn".equalsIgnoreCase(lvl)) {
    235            setLevel(SimpleLog.LOG_LEVEL_WARN);
    236        } else if ("error".equalsIgnoreCase(lvl)) {
    237            setLevel(SimpleLog.LOG_LEVEL_ERROR);
    238        } else if ("fatal".equalsIgnoreCase(lvl)) {
    239            setLevel(SimpleLog.LOG_LEVEL_FATAL);
    240        } else if ("off".equalsIgnoreCase(lvl)) {
    241            setLevel(SimpleLog.LOG_LEVEL_OFF);
    242        }
    243
    244    }
    245
    246    // -------------------------------------------------------- Properties
    247
    248    /**
    249     * <p>
    250     * Set logging level.
    251     * </p>
    252     *
    253     * @param currentLogLevel
    254     *          new logging level
    255     */
    256    public void setLevel(int currentLogLevel) {
    257
    258        this.currentLogLevel = currentLogLevel;
    259
    260    }
    261
    262    /**
    263     * <p>
    264     * Get logging level.
    265     * </p>
    266     */
    267    public int getLevel() {
    268
    269        return currentLogLevel;
    270    }
    271
    272    // -------------------------------------------------------- Logging Methods
    273
    274    /**
    275     * <p>
    276     * Do the actual logging. This method assembles the message and then calls
    277     * <code>write()</code> to cause it to be written.
    278     * </p>
    279     *
    280     * @param type
    281     *          One of the LOG_LEVEL_XXX constants defining the log level
    282     * @param message
    283     *          The message itself (typically a String)
    284     * @param t
    285     *          The exception whose stack trace should be logged
    286     */
    287    protected void log(int type, Object message, Throwable t) {
    288        // Use a string buffer for better performance
    289        StringBuffer buf = new StringBuffer();
    290
    291        // Append date-time if so configured
    292        if (showDateTime) {
    293            buf.append(dateFormatter.format(new Date()));
    294            buf.append(" ");
    295        }
    296
    297        // Append a readable representation of the log level
    298        switch (type) {
    299        case SimpleLog.LOG_LEVEL_TRACE:
    300            buf.append("[TRACE] ");
    301            break;
    302        case SimpleLog.LOG_LEVEL_DEBUG:
    303            buf.append("[DEBUG] ");
    304            break;
    305        case SimpleLog.LOG_LEVEL_INFO:
    306            buf.append("[INFO] ");
    307            break;
    308        case SimpleLog.LOG_LEVEL_WARN:
    309            buf.append("[WARN] ");
    310            break;
    311        case SimpleLog.LOG_LEVEL_ERROR:
    312            buf.append("[ERROR] ");
    313            break;
    314        case SimpleLog.LOG_LEVEL_FATAL:
    315            buf.append("[FATAL] ");
    316            break;
    317        }
    318
    319        // Append the name of the log instance if so configured
    320        if (showShortName) {
    321            if (shortLogName == null) {
    322                // Cut all but the last component of the name for both styles
    323                shortLogName = logName.substring(logName.lastIndexOf(".") + 1);
    324                shortLogName = shortLogName.substring(shortLogName.lastIndexOf("/") + 1);
    325            }
    326            buf.append(String.valueOf(shortLogName)).append(" - ");
    327        } else if (showLogName) {
    328            buf.append(String.valueOf(logName)).append(" - ");
    329        }
    330
    331        // Append the message
    332        buf.append(String.valueOf(message));
    333
    334        // Append stack trace if not null
    335        if (t != null) {
    336            buf.append(" <");
    337            buf.append(t.toString());
    338            buf.append(">");
    339
    340            java.io.StringWriter sw = new java.io.StringWriter(1024);
    341            java.io.PrintWriter pw = new java.io.PrintWriter(sw);
    342            t.printStackTrace(pw);
    343            pw.close();
    344            buf.append(sw.toString());
    345        }
    346
    347        // Print to the appropriate destination
    348        write(buf);
    349
    350    }
    351
    352    /**
    353     * <p>
    354     * Write the content of the message accumulated in the specified
    355     * <code>StringBuffer</code> to the appropriate output destination. The
    356     * default implementation writes to <code>System.err</code>.
    357     * </p>
    358     *
    359     * @param buffer
    360     *          A <code>StringBuffer</code> containing the accumulated text to be
    361     *          logged
    362     */
    363    protected void write(StringBuffer buffer) {
    364
    365        System.err.println(buffer.toString());
    366
    367    }
    368
    369    /**
    370     * Is the given log level currently enabled?
    371     *
    372     * @param logLevel
    373     *          is this level enabled?
    374     */
    375    protected boolean isLevelEnabled(int logLevel) {
    376        // log level are numerically ordered so can use simple numeric
    377        // comparison
    378        return (logLevel >= currentLogLevel);
    379    }
    380
    381    // -------------------------------------------------------- Log Implementation
    382
    383    /**
    384     * <p>
    385     * Log a message with debug log level.
    386     * </p>
    387     */
    388    public final void debug(Object message) {
    389
    390        if (isLevelEnabled(SimpleLog.LOG_LEVEL_DEBUG)) {
    391            log(SimpleLog.LOG_LEVEL_DEBUG, message, null);
    392        }
    393    }
    394
    395    /**
    396     * <p>
    397     * Log an error with debug log level.
    398     * </p>
    399     */
    400    public final void debug(Object message, Throwable t) {
    401
    402        if (isLevelEnabled(SimpleLog.LOG_LEVEL_DEBUG)) {
    403            log(SimpleLog.LOG_LEVEL_DEBUG, message, t);
    404        }
    405    }
    406
    407    /**
    408     * <p>
    409     * Log a message with trace log level.
    410     * </p>
    411     */
    412    public final void trace(Object message) {
    413
    414        if (isLevelEnabled(SimpleLog.LOG_LEVEL_TRACE)) {
    415            log(SimpleLog.LOG_LEVEL_TRACE, message, null);
    416        }
    417    }
    418
    419    /**
    420     * <p>
    421     * Log an error with trace log level.
    422     * </p>
    423     */
    424    public final void trace(Object message, Throwable t) {
    425
    426        if (isLevelEnabled(SimpleLog.LOG_LEVEL_TRACE)) {
    427            log(SimpleLog.LOG_LEVEL_TRACE, message, t);
    428        }
    429    }
    430
    431    /**
    432     * <p>
    433     * Log a message with info log level.
    434     * </p>
    435     */
    436    public final void info(Object message) {
    437
    438        if (isLevelEnabled(SimpleLog.LOG_LEVEL_INFO)) {
    439            log(SimpleLog.LOG_LEVEL_INFO, message, null);
    440        }
    441    }
    442
    443    /**
    444     * <p>
    445     * Log an error with info log level.
    446     * </p>
    447     */
    448    public final void info(Object message, Throwable t) {
    449
    450        if (isLevelEnabled(SimpleLog.LOG_LEVEL_INFO)) {
    451            log(SimpleLog.LOG_LEVEL_INFO, message, t);
    452        }
    453    }
    454
    455    /**
    456     * <p>
    457     * Log a message with warn log level.
    458     * </p>
    459     */
    460    public final void warn(Object message) {
    461
    462        if (isLevelEnabled(SimpleLog.LOG_LEVEL_WARN)) {
    463            log(SimpleLog.LOG_LEVEL_WARN, message, null);
    464        }
    465    }
    466
    467    /**
    468     * <p>
    469     * Log an error with warn log level.
    470     * </p>
    471     */
    472    public final void warn(Object message, Throwable t) {
    473
    474        if (isLevelEnabled(SimpleLog.LOG_LEVEL_WARN)) {
    475            log(SimpleLog.LOG_LEVEL_WARN, message, t);
    476        }
    477    }
    478
    479    /**
    480     * <p>
    481     * Log a message with error log level.
    482     * </p>
    483     */
    484    public final void error(Object message) {
    485
    486        if (isLevelEnabled(SimpleLog.LOG_LEVEL_ERROR)) {
    487            log(SimpleLog.LOG_LEVEL_ERROR, message, null);
    488        }
    489    }
    490
    491    /**
    492     * <p>
    493     * Log an error with error log level.
    494     * </p>
    495     */
    496    public final void error(Object message, Throwable t) {
    497
    498        if (isLevelEnabled(SimpleLog.LOG_LEVEL_ERROR)) {
    499            log(SimpleLog.LOG_LEVEL_ERROR, message, t);
    500        }
    501    }
    502
    503    /**
    504     * <p>
    505     * Log a message with fatal log level.
    506     * </p>
    507     */
    508    public final void fatal(Object message) {
    509
    510        if (isLevelEnabled(SimpleLog.LOG_LEVEL_FATAL)) {
    511            log(SimpleLog.LOG_LEVEL_FATAL, message, null);
    512        }
    513    }
    514
    515    /**
    516     * <p>
    517     * Log an error with fatal log level.
    518     * </p>
    519     */
    520    public final void fatal(Object message, Throwable t) {
    521
    522        if (isLevelEnabled(SimpleLog.LOG_LEVEL_FATAL)) {
    523            log(SimpleLog.LOG_LEVEL_FATAL, message, t);
    524        }
    525    }
    526
    527    /**
    528     * <p>
    529     * Are debug messages currently enabled?
    530     * </p>
    531     *
    532     * <p>
    533     * This allows expensive operations such as <code>String</code> concatenation
    534     * to be avoided when the message will be ignored by the logger.
    535     * </p>
    536     */
    537    public final boolean isDebugEnabled() {
    538
    539        return isLevelEnabled(SimpleLog.LOG_LEVEL_DEBUG);
    540    }
    541
    542    /**
    543     * <p>
    544     * Are error messages currently enabled?
    545     * </p>
    546     *
    547     * <p>
    548     * This allows expensive operations such as <code>String</code> concatenation
    549     * to be avoided when the message will be ignored by the logger.
    550     * </p>
    551     */
    552    public final boolean isErrorEnabled() {
    553
    554        return isLevelEnabled(SimpleLog.LOG_LEVEL_ERROR);
    555    }
    556
    557    /**
    558     * <p>
    559     * Are fatal messages currently enabled?
    560     * </p>
    561     *
    562     * <p>
    563     * This allows expensive operations such as <code>String</code> concatenation
    564     * to be avoided when the message will be ignored by the logger.
    565     * </p>
    566     */
    567    public final boolean isFatalEnabled() {
    568
    569        return isLevelEnabled(SimpleLog.LOG_LEVEL_FATAL);
    570    }
    571
    572    /**
    573     * <p>
    574     * Are info messages currently enabled?
    575     * </p>
    576     *
    577     * <p>
    578     * This allows expensive operations such as <code>String</code> concatenation
    579     * to be avoided when the message will be ignored by the logger.
    580     * </p>
    581     */
    582    public final boolean isInfoEnabled() {
    583
    584        return isLevelEnabled(SimpleLog.LOG_LEVEL_INFO);
    585    }
    586
    587    /**
    588     * <p>
    589     * Are trace messages currently enabled?
    590     * </p>
    591     *
    592     * <p>
    593     * This allows expensive operations such as <code>String</code> concatenation
    594     * to be avoided when the message will be ignored by the logger.
    595     * </p>
    596     */
    597    public final boolean isTraceEnabled() {
    598
    599        return isLevelEnabled(SimpleLog.LOG_LEVEL_TRACE);
    600    }
    601
    602    /**
    603     * <p>
    604     * Are warn messages currently enabled?
    605     * </p>
    606     *
    607     * <p>
    608     * This allows expensive operations such as <code>String</code> concatenation
    609     * to be avoided when the message will be ignored by the logger.
    610     * </p>
    611     */
    612    public final boolean isWarnEnabled() {
    613
    614        return isLevelEnabled(SimpleLog.LOG_LEVEL_WARN);
    615    }
    616
    617    /**
    618     * Return the thread context class loader if available. Otherwise return null.
    619     *
    620     * The thread context class loader is available for JDK 1.2 or later, if
    621     * certain security conditions are met.
    622     *
    623     * @exception LogConfigurationException
    624     *              if a suitable class loader cannot be identified.
    625     */
    626    private static ClassLoader getContextClassLoader() {
    627        ClassLoader classLoader = null;
    628
    629        if (classLoader == null) {
    630            try {
    631                // Are we running on a JDK 1.2 or later system?
    632                Method method = Thread.class.getMethod("getContextClassLoader");
    633
    634                // Get the thread context class loader (if there is one)
    635                try {
    636                    classLoader = (ClassLoader) method.invoke(Thread.currentThread());
    637                } catch (IllegalAccessException e) {
    638                    ; // ignore
    639                } catch (InvocationTargetException e) {
    640                    /**
    641                     * InvocationTargetException is thrown by 'invoke' when the method
    642                     * being invoked (getContextClassLoader) throws an exception.
    643                     *
    644                     * getContextClassLoader() throws SecurityException when the context
    645                     * class loader isn't an ancestor of the calling class's class loader,
    646                     * or if security permissions are restricted.
    647                     *
    648                     * In the first case (not related), we want to ignore and keep going.
    649                     * We cannot help but also ignore the second with the logic below, but
    650                     * other calls elsewhere (to obtain a class loader) will trigger this
    651                     * exception where we can make a distinction.
    652                     */
    653                    if (e.getTargetException() instanceof SecurityException) {
    654                        ; // ignore
    655                    } else {
    656                        // Capture 'e.getTargetException()' exception for details
    657                        // alternate: log 'e.getTargetException()', and pass back 'e'.
    658                        throw new LogConfigurationException("Unexpected InvocationTargetException", e.getTargetException());
    659                    }
    660                }
    661            } catch (NoSuchMethodException e) {
    662                // Assume we are running on JDK 1.1
    663                ; // ignore
    664            }
    665        }
    666
    667        if (classLoader == null) {
    668            classLoader = SimpleLog.class.getClassLoader();
    669        }
    670
    671        // Return the selected class loader
    672        return classLoader;
    673    }
    674
    675    private static InputStream getResourceAsStream(final String name) {
    676        return AccessController.doPrivileged(new PrivilegedAction<InputStream>() {
    677            public InputStream run() {
    678                ClassLoader threadCL = getContextClassLoader();
    679
    680                if (threadCL != null) {
    681                    return threadCL.getResourceAsStream(name);
    682                } else {
    683                    return ClassLoader.getSystemResourceAsStream(name);
    684                }
    685            }
    686        });
    687    }
    688}