[*] Changes that are 100% compatible with existing client code. [**] Changes that requiring little or no modification to existing client code. [***] Changes requiring important modifications to existing client code. May 20, 2001 - Release of version 1.1.1. - Added missing custom priority support in PropertyConfigurator. [*] - Made a number of fields protected instead of default access in SMTPAppender. [*] May 19, 2001 - Release of version 1.1. - This release has the same code as 1.1b7. It differs only in a few minor documentation changes. May 9, 2001 - Release of version 1.1b7 - Made BasicConfigurator disable methods static as they were in log4j 1.0.4. Thanks to Francisco Marin for reporting the bug. [*] - Corrected a two related deadlock problems introduced while fixing bug 1505. Thanks to joelr@viair.com for reporting the problem. [*] - The configureAndWatch methods in Configurators did not close the configuration file, preventing its editing. See bug 1686. [*] - In DOMConfigurator.setParameter special charater conversion now preceeds variable substitution. This change was suggested by Steven Velez. The vast majority of users should be oblivious to it. [*] - The TextPaneAppender is no longer maintained and has been removed. It is still available under the contribs/ directory. This change has been discussed in the log4j mailing lists and no one objected to the removal of the TextPaneAppender class. April 26, 2001 - Release of version 1.1b6 - Aaron Greenhouse from Carnegie Mellon SCS found a series of multi-threading related bugs in Category and AsyncAppender. See bug ids 1505 and 1507 in our bug database for examplary bug reports. They are worth the detour. [*] - InvalidJarIndexException is only available in JDK 1.3. Referring to this exception type caused log4j 1.1b5 to break on earlier JDKs. We now avoid referring to it. [*] - Added PriorityRangeFilter by Simon Kitching. See the Threshold option in AppenderSkeleton for a more convenient alternative. [*] April 22, 2001 - Release of version 1.1b5 - In HTMLLayout, the Title option sets the HTML document title (...<title>). [*] - Corrected an important performance bug in LocationInfo. Hein Couwet and kr@it-practice.dk have independently identified the bug. This is yet another example of the difference made by the number of eyeballs studying source code. [*] - Corrected the incorrect value returned by LocationInfo.getClassName method when running under IBM Visual Age. Thanks to Mathias Rupprecht for supplying the relevant patch. [*] - Corrected a bug where the build.sh file in the distribution would be in DOS CRLF format. Thanks to ma.darche@free.fr for reporting the problem. [*] - Corrected InvalidJarIndexException thrown in applets while searching for the default log4j configuration file. Thanks to Michael Lundahl for reporting this bug. [*] - Added missing PropertySetterException class to log4j-core.jar. Thanks to ma.darche@free.fr for reporting this bug. [*] April 20, 2001 - Release of version 1.1b4 - Mathias Bogaert observed that in version 1.1b3 the search algorithm for the resource used in automatic log4j configuration was different than in 1.0.x. Beta4 uses a more powerful mechanism which is also compatible with 1.0.x. [*] - Paul Glezen correctly observed that if log4j is deployed in a client/server mode where multiple log4j clients log to a log4j server, all hosts must be upgraded to version 1.1 in one go because the internal LoggingEvent class used in client/server communication changed in log4j 1.1. April 18, 2001 - Release of version 1.1b3 - Added a RollingFileAppenderBeanInfo class that fakes the maxFileSize JavaBeans property as a String type instead of a long. This allows us to resuscitate setMaxFileSize(long) method that was removed in 1.1b2 breaking 100% backward compatibility. This addition restores 100% backward compatibility. [*] April 18, 2001 - Release of version 1.1b2 - The directory structure has changed to better suit Jakarta conventions as follows: org/** --> src/java/org/** xdocs/** --> src/xdocs/** If you have a CVS checked out copy of log4j be sure to check out a fresh copy. [*] - Added a few jar files required at build time to build/lib so that it is now possible to compile log4j out of the box. [*] - Whenever a priority parameter is expected in a configuration file, one can now use a custom priority class. See OptionConverter.toPriority method for more information. Note that the <priority> element in log4j.dtd remains unaffected by this change. [*] - Added the setQuietMode(boolean) method to LogLog. In quiet mode LogLog will not output anything even in case of errors. [*] - Log4j components are now configured as JavaBeans. The setOption and getOptionString methods have been deprecated in OptionHandler interface which is implemented by most log4j components. [*] - The stack trace of a throwable passed in a logging statement is not parsed into a stack array which is serializable. This allows cascading of log4j servers to properly propagate throwable information. [*] - In XML configuration files, the <configuration> element has been deprecated and was replaced by the <log4j:configuration> element. [*] The following perl command can help to migrate: perl -p -i.bak -e "s/configuration/log4j:configuration/;" file1.xml .. fileN.xml - The "log4j.configDebug" system property has been replaced with the "log4j.debug" system property although it is still available. Similarly, the "configDebug" attribute has been deprecated and replaced with the "debug" attribute in log4j.dtd. [*] February 23, 2001 - Release of version 1.1b1 - Logging can now be disabled per Hierarchy. It can also be disabled using configuration files using the "disable" directive. The "disableOverride" directive takes precedence over the "disable" directive. As a result of this change the disable family of methods in BasicConfigurator has been deprecated and replaced by the same family of methods in the Hierarchy class. [*] - The FileAppender has been split into three parts: WriterAppender, ConsoleAppender and FileAppender. ConsoleAppender takes over the console logging functionality of FileAppender. As a result support for stream and console printing has been deprecated in FileAppender. [**] - The FileAppender now correctly outputs the header and footer of its layout. This problem was reported by too many users to list here. [*] - Appenders and Layouts now get to see the raw message object in LoggingEvent not just its rendered form. The access modifiers of some LoggingEvent fields were changed so that they can be accessed in less error-prone ways. Thanks to Jim Cakalic and Anders Kristens for their valuable advice. [*] - Added getLayout(), getErrorHandler(), and getFilter() to the Appender interface. [*] - Added getOption(key) method to the OptionHandler interface and modified implementations of it as appropriate. [*] - Added the much awaited DailyRollingFileAppender. [*] - The structure of the distribution changed somewhat. The log4j.jar files can be found under dist/. The javadoc directory has been moved to docs/api/. We are now totally dependent on ANT to perform all the steps involved in creating a release, including compilation, jar file creation, generation of the javadocs, and for the creation of the distribution tar and zip files. [*] - Removed org/apache/log4j/varia/ResilientFileAppender.java which was bogus to begin with. [*] - XMLLayout will now mark some output as <![CDATA[ .. ]]> so that it does not get interpreted by the XML parser. This was suggested by Mathias Bogaert like a long list of other fixes. [*] - Corrected a bug in CyclicBuffer.resize method that would not update the next insertion point. Thanks to Ole Bulbuk for accurately reporting the bug. [*] - The LoggingEvent class now supports serialization of priorities derived from the org.apache.log4j.Priority class. [*] - Improved the search method for finding the "log4j.properties" file in the static initializer of Category class. Thanks to Calvin Chan for supplying a better method. [*] - The code handling the FCQN (formerly instanceFQN) parameter was cleaned up. There is now a well-established and simple manner for sub-classes of Category (or wrapper classes) to define the FCQN variable: just define a static variable, say FCQN, consisting of the fully qualified class name of the subclass or wrapper, supply this variable as an argument to forcedLog method if and when the sub-class or wrapper invokes that method. [*] - Made the instanceFCQN an instance variable instead of a class static in Category.java. In related move, the Category constructor now takes an additional argument setting the instanceFCQN. This makes life less miserable for Category subclasses. [*] - Corrected a bug in the OptionConverter.instantiateByClassName method that would not return the defaultValue in case of error. Thanks to Matthieu Verbert for identifying this bug. - Corrected the missing stack trace in e-mails generated by the SMTPAppender when using certain Layouts. [*] - Updated the "Adding Conversion Characters to PatternLayout" document to reflect the latest changes to the code. Also added the org/apache/log4j/examples/appserver directory containing the associated example code. [*] - Added the BufferSize option to the AsyncAppender. [*] - Eliminated the SecurityExceptions thrown in Applets. Thanks Timur Zambalayev for reporting this bug. [*] - Fixed the erroneously thrown IOInterruptedException when the AsyncAppender was closed. Thanks to Tom Palmer for accurately reporting this bug. [*] January 12th, 2001 - Release of version 1.0.4 (the 20th major release) - Corrected a serious bug in Hierarchy.java that would cause a NullPointerException depending on the order of instantiation of categories. Thanks to Wolfram Gewohn for reporting this bug. [*] - Corrected a bug in the getOptionsStrings method of SMTPAppender that omitted to mention the EvaluatorClass option. Thanks to Mark Balster for reporting this bug. [*] January 11th, 2001 - Release of version 1.0.3 (the 20th major release) - Fixed a NullPointerException occurring in AsyncAppender after invoking Category.shutdown. Thanks to Frank-Olaf Lohmann for reporting this bug. [*] - Modified the OptionConverter.selectAndConfigure method to take an extra argument of type Hierarchy. This method is used internally and should not affect most users. [*/**] - Added the warn method to LogLog which is used internally by log4j to report on itself. [*] - Displaced a number of HTML files under the docs directory. The new structure is compatible with the jakarta site and results in a more consistent navigation experience. [*] - Made a few improvements in the javadocs. [*] January 11th, 2001 - Release of version 1.0.2 (the 20th major release) - Added the missing build.inc file to the distribution. No code changed. January 10th, 2001 - Release of version 1.0.1 (the 20th major release) - This version corrects some documentation and build script bugs; code has not changed. January 8th, 2001 - Release of version 1.0 (the 20th major release) - Package hierarchy now starts at org.apache.log4j. [***] The following perl command can help in the transition: > perl -p -i.bak -e "s/org.log4j/org.apache.log4j/;" file1.java .. fileN.java - Added the fatal() family of methods to the Category class. Moreover, the EMERG priority has been removed from the Priority class. This priority has been replaced by the FATAL priority that is more widely accepted. This change will require EMERG log statements to be replaced by FATAL log statements. Assuming EMERG log statements are rare, this should have a small but bearable impact on existing client code. Moreover, the Unix Syslog priorities ALERT, CRIT and NOTICE are no longer recognized. Support for these priorities was minimal and few users should suffer from these changes. [**] - Removed the methods setRootPriority, getRootPriority as these methods were redundant and had been previously deprecated. [**] - Removed the DOM Level 2 dependency in DOMConfigurator. This makes log4j XML configurable using Sun's parser or Apache's Xerces. [*] - The static initializer of the Category class now takes the log4j.configuration system property to search for its configuration file. The type of the configurator used to parse the configuration file depends on the value of the log4j.configuration system property. [*] - Enhanced the PropertyConfigurator and DOMConfigurator to support customisation of independent Hierarchy instances. The org.apache.log4j.net.SocketServer has been enhanced to take advantage of this functionality. The old code of SocketServer has been moved to SimpleSocketServer. [**] - Enhanced the PropertyConfigurator to support variable substitution for all options *values* (but not keys!). [*] - Categories are now aware of the Hierarchy they are linked to. This will provide a basis for several performance enhancements planned for the future. [*] - Added support for object rendering. It is now possible to register an object renderer for a given object type. When the given object needs to be logged log4j will invoke the corresponding renderer to transform the object into a String. As a result of this enhancement, all the String forms of all the printing methods such as debug(String), info(String) have been removed as they are no longer necessary. This change should be backward compatible but requires recompilation of old client code. Thanks to Michael Smith for noting the recompilation requirement. [**] - Added support for user defined category factories in the PropertyConfigurator. Thus, it is now possible to configure log4j with a properties file and still use custom Category sub-classes. The DOMConfigurator had already a finer grain support. [*] - Added the SMTPAppender that in case of an error or fatal event sends an e-mail containing latest N logging events in its buffer, where N is chosen by the user. [*] - Added the method getInstance(Class) to the Category class. [*] - Corrected a bug in configureAndWatch method of configurators that would configure log4j only after an unnecessary delay. [*] November 30, 2000 - Release of version 0.9.1 (the 19th public release) - Corrected a typo making NTEventLogAppender.dll register the wrong category message file. Thanks to Peter Hayes for accurately reporting this bug. [*] - The DOMConfigurator and PropertyConfigurator can now automatically detect modified configuration files and re-read them. [*] - Added AsyncAppender which buffers log requests and serves them at a later time. AsyncAppender can increase logging performance tremendously if logging operations are interspersed with long and blocking non CPU-intensive operations, typically I/O or network access. For CPU intensive applications, using the AsyncAppender will actualy degrade logging performance by 10 to 25 percent. [*] - The log4j.dtd has been modified to allow appenders to refer to other appenders by IDREF. [*] - The DOMConfigurator has been modified to take advantage of ID/IDREF attributes when referring to appenders. This change requires a DOM Level-2 API compliant parser. DOM Level-2 java bindings are available at http://www.w3.org/TR/1999/WD-DOM-Level-2-19990923/java-binding.html. - Added the configure(String filename) method to DOMConfigurator. This method requires the presence of a JAXP compatible parser. At this time, the only DOM2 and JAXP compatible parser seems to be the Apache xerces parser. - Added the PriorityMatchFilter allowing filtering by exact priority match. This was a common request by users. [*] - The configuration of a category is now an atomic operation. This ensures that log requests are not lost while configuration is in progress. Anders Kristensen was to first to observe the potential problems in non-atomic configurations. [*] November 20th, 2000 - Release of version 0.9.0 (the 18th public release) - The "log4j" element has been renamed to "configuration" in the log4j DTD. This change requires that log4j configuration files written in XML be modified. Since the log4j element figures only once in the XML file, this change should take little time. [**] - ResourceBundles are now category instance specific and no longer class static. Moreover, like other properties resource bundles are inherited from the category hierarchy. [**] - The jar files log4j.jar and log4j-full.jar now contain versioning information in their respective manifest files. [*] - Corrected an inconsistency in the NTEventLogAppender which broke it. - Fixed a bug where configuration files were not parsed correctely due to trailing spaces in option values as returned by java.util.Properties. Trailing spaces are now removed from option values. This bug was quite disconcerting because the trailing spaces cannot be seen without careful examination of the configuration file. [*] - Added the XMLLayout. The output of the XMLLayout consists of a series of log4j:event elements. It does not output a complete XML file. The output is designed to be included as an external entity to form a well-formed XML file. [*] - Added a new abstract class org.log4j.helpers.DateLayout. The TTCCLayout now extends DateLayout. [*] - Corrected a rather subtle performance bug in the buffer management code in PatternLayout. Thanks to Vladislav Dutov and Constantine A. Plotnikov for for insisting on the correction of this bug. [*] - Created a new package called org.log4j.spi. This new package holds classes that are hidden from the casual user but are needed to extend log4j. [*] - Added org.log4j.varia.ExternallyRolledFileAppender to handle externally triggered file rollovers. [*] - Added support for multiple hierarchy trees. [*] - PatternLayout can now be subclassed to support new conversion patterns. [*] - Extended the DOMConfigurator and the log4j DTD to properly handle sub-classing of Category and Priority classes. There have been also minor adjustments to other classes to handle sub-classing. These changes should be invisible to users. All categories except the root category can be sub-classed and also assigned priorities sub-classing org.log4j.Priority. The root category always exists and CANNOT be subclassed. The ProppertyConfigurator remains unchanged. Thus, it does not handle extensions of the Category class. [*] - Added filter support in appenders. The DOMConfigurator and the log4j.dtd have been enhanced to support filters. [*] - Added error handling support to appenders. The DOMConfigurator and the log4j.dtd have been enhanced to support filters. [*] - Added support for correct interpretation of location information in IBM's Visual Age environment. Thanks to Wolf Siberski for supplying the relevant patch. [*] - Added getAdditivity method to Category. This feature was requested by Constantin Mitran. (mitran at ecircle.de) [*] August 27, 2000 - Release of version 0.8.5b. - Corrected multiple bugs in default initialization code of Category class. Thanks to Jeff Turner for identifying and supplying corrective patches. [*] August 24, 2000 - Release of version 0.8.5a. - Added the %n conversion character to PatternLayout so that a line separator can be specified in a platform independent way. [*] - In 0.8.5 internal Priority integer values were decoupled from the Unix Syslog values. This broke SyslogAppedder. A new function Priority.toSyslogInt is introduced to solve this bug. [*] Corrected a bug where the internal prtar tzvf iority integer August 23, 2000 - Release of version 0.8.5. - All log4j internal output is now prepended with the string "log4j: ". This makes is easier to differentiate log4j internal logs from messages output by other sources. [*] - Sub-classes of Category class must now specify their fully qualified name when constructing logging events. This allows the %C conversion specifier in PatternLayout to work properly even with sub-classes or wrappers of Category. [*] - Added the method disableDebug to BasicConfigurator. This method disables all print requests of debug priority regardless its category. Similar methods disableInfo, disable, disableAll and enableAll have also been added. Disable type methods can be overriden by setting the log4j.disableOverride system property. Calling BasicConfigurator.disableInfo is equivalent to the now deprecated flagAsShippedCode method. [*] - Given the above changes, the system property log4j.shippedCodeFlagOverride is no longer honored. [**] - It is now possible to sub-class Category. The sub-classes may continue to adhere to the category hierarchy. This was a frequently requested feature. [*] - Corrected a problem with the additivity flag being ignored in categories without appenders. This bug was discovered by Anders Kristensen. [*] - Added a method BasicConfigurator.resetConfiguration to reset the log4j environment. This method should be used sparingly. [*] - At the initialization of the Category class, the file log4j.properties will now be searched from the search path used to load classes. If the file can be found, then it is fed to the PropertyConfigurator.configure(java.net.URL) method. [*] - Failing to access system properties within the static initializer of BasicConfigurator class is no longer reported as an error but as a debug message. Thanks to Gilles Schlienger for reporting this problem with applets. [*] - Corrected a bug which caused infinite loops when using conversion patterns with a single element, fortunately under very rare circumstances. This bug was first reported by Igor Potraev, the author of log4p. It was independently reported by Joe Haberl from IBM Global Services. [*] - Added a mechanism to lazily remove references to dead threads in the NDC class. Indeed, in previous versions calling NDC.pop within a thread but forgetting to call to NDC.remove before exiting (that thread) resulted in a memory leak. [*] - Corrected a huge memory leak in SocketAppender. This leak was due to the ObjectOutputStream indefinitely holding a reference for each written to the stream. Thanks to Dan MacDonald for very accurately describing this bug. [*] - The log and l7dlog methods in Category no longer ignore the shipped code flag. This bug was reported by Mario Schomburg. [*] - Added missing NDC information to LoggingEvent.writeObject method. [*] - Corrected handling of SocketException in SocketNode. Thanks to Gerald Gutierez (ggutierez@emobiledata.com) for reporting this and the previous problem. [*] - Phased out custom shell scripts to build java documentation and jar files in favor of Jakarta's ANT. It was becoming a nuisance to keep the ANT build file in sync with the custom shell scripts. [*] May 11, 2000 - Release of version 0.8.4d. - The NT EventViewer no longer complains about missing message 4096. - Minor corrections in documentation. - Added missing icons GIFs into the distribution. - SocketNode now attempts to close the socket when exiting. Thanks to Moses Hohman (mmhohman@rainbow.uchicago.edu) for noting this. - Removed the com.ibm.log4j from the javadoc directory. This seems to confuse VAJ. Thanks to Steve Ashcroft for reporting this problem. May 5, 2000 - Release of version 0.8.4c. - As a result of the infinite loop problem (see next item), added over 800 new test cases to stress-test the code in CategoryFactory class where category creation occurs. [*] - Under certain rare circumstances the Category.getInstance method entered an infinite loop. Thanks to Mario Schomburg from IBM Global Services / Hannover for identifying this problem and proposing a patch. [*] - DOMConfigurator and the log4j.dtd were out of sync on the type of the priority directive. As a result, priority directives all defaulted to DEBUG. Thanks to Peter (petervt@users.sourceforge.net) for accurately reporting this bug. [*] - Minor additions to the FAQ. [*] - Added the NumberCruncher example showing how the NDC class can be used to distinguish output from different clients. [*] - Added the %x conversion specifier to the TTCC_CONVERSION_PATTERN in the PatternLayout class. This is consistent expected output of Trivial.java example. Thanks to Jerome (schrom@users.sourceforge.net) for reporting this bug. [*] May 3, 2000 - Release of version 0.8.4b. - The value of the additivity option would not be parsed properly by the ProperytConfigurator if the line containing the option contained trailing spaces. [*] - Release of version 0.8.4a. - The localized logging methods (l7dlog) omitted priority based evaluation and erroneously logged all requests. [*] May 1, 2000 - Release of version 0.8.4. - The close method was added to the Appender interface allowing appender implementations to release any resources they may have allocated. [*] - The package naming scheme of changed from "com.ibm.log4j.*" to "org.log4j.*". The new naming reflects the open source nature of the project and is consistent with the URL http://www.log4j.org. [***] - Added internationalization support. See the newly introduced l7dlog methods in Category class. [*] - In the FileAppender, the File option now admits variable substitution. For example, if "java.home" system property is set to /home/xyz and the File option is given the value "%{java.home}/test.log", then File option will be interpreted as "/home/xyz/test.log". Thanks to Avy Sharell (sharell@online.fr) for contributing this feature. [*] - SocketAppender is now officially part of the package. It is capable of sending logging events to a remote SocketNode. The SocketNode logs events according to server (local) policy. For example, a client can log events to a local file and also send them to a remote server (a SocketNode). This server can log the event to any number of files, to the console, to any number of TextPaneAppenders and even re-transmit the event to another server, and so forth. This paradigm is common in most logging systems, e.g. Syslog and NT Event Log. Many thanks to Andrew Harrison for showing a way to actually implement the paradigm. [*] - The Category.callAppenders method now accepts a LoggingEvent instead of creating one itself. This was necessary to accommodate events generated at a remote client. [*] - LoggingEvent class changed slightly to support remote logging. The category field (a Category) has been replaced by the categoryName field (a String). [*] April 14, 2000 Release of version 0.8.3b - Corrected a bug in Category.removeAppender(String) which would never remove the desired appender. Thanks to Moses Hohman for reporting this bug. Release of version 0.8.3a - Corrected a bug RollingFileAppender which would throw an uncaught exception in case output file could not be opened for writing. Thanks to Vinay Aggarwal for signaling this problem. April 13, 2000 - Release of version 0.8.3. - The log4j.override key defined in BasicConfigurator has been renamed to log4j.shippedCodeFlagOverride. [**] - The getCurrentCategories method in the Category class would not return the correct value. Thanks to Timothy Potter (tpotter@agency.com) for reporting this problem. [*] - Appenders now admit a priority threshold as an option. All requests with a priority lower than the appender's threshold priority are ignored by the appender. [*] - Integrated Christopher Taylor's DOMConfigurator parsing XML configuration files. [*] - The jar file log4j-net.jar has been replaced by log4j-full.jar. It contains DOMConfigurator.class in addition to the com.ibm.log4j.net package. [**] - Added support for the ANT build tool. Thanks to Christopher Taylor for supplying the build.xml file. ANT is available form http://jakarta.apache.org. [*] - FileAppender's File option now accepts the values "System.out" or "System.err". If one these values is suppiled in a configuration file then the output is directed to the corresponding stream. Moreover, the default constructor of FileAppender no longer sets System.out as an output target nor does it define a default layout. [*] - Added caller class (C), caller file name (F), caller line number (L), caller method name (M) conversion specifiers to the PatternLayout class. The category conversion specifier now takes an optional precision modifier allowing the user to control the number of right most components in the category name that will be printed. Corrected a bug occuring when the caller file name and line number information were unavilable due to JIT compilation. In that case, the PatternLayout would not properly use the rest of the available location information. [*] The above enhancements and bug-fixes originate from comments by Nelson Minar (nelson@monkey.org). March 23, 2000 - Release of version 0.8.2. - The SimpleLayout and TTCCLayout are replaced by the PatternLayout in the log4j.jar file to keep its size small. These two layouts are still part of the package. - The PatternLayout class is introduced. This new layout is configurable using a conversion pattern which is parsed at runtime. This allows the user to choose the output layout without writing any code and only at a marginal performance cost compared to the dedicated layouts such as SimpleLayout and TTCCLayout. The PatternLayout also allows the user to determine minimum and maximum field lengths. The PatternLayout was written by Jim Cakalic (jim_cakalic@na.biomerieux.com). [*] - All internal components now use LoggingEvent instances to specifiy logging information. - Corrected a problem with a missing variable initialization in SyslogAppender. This caused NullPinterException to be thrown when logging exceptions. Added a default constructor to SyslogAppender. The lack of this constructor caused PropertyConfigurator to throw a java.lang.InstantiationException when the appender type was set to be SyslogAppender. Thanks to Yves Bossel (ybossel@opengets.cl) for accurately identifying these bugs. Modified some other related option handling code in SyslogAppender. [*] - Made NDC.get public access instead of default access. Thanks to Y. J. Chun (monac@softonnet.com) for reporting this problem. [*] - PropertyConfigurator now parses the additivity option for categories. [*] - Corrected the value of the ADDITIVITY_PREFIX constant to match the documented value, that is "log4j.additivity". [**] - Corrected a really bad bug where System.out would be closed when PropertyConfigurator.configure was called. Thanks to Christopher Taylor (cstaylor@pacbell.net) for tracking and reporting this bug. [*] - The PropertyConfiguator now prints debug messages if the flag "log4j.configDebug" is defined in the configuration file. Previously, only if the system property "log4j.configDebug" was set would debug messages be printed. A question by Shawn Kircher (skircher@vninet.com) induced this change. [*] - In AbsoluteTimeDateFormat, DateTimeDateFormat and ISO8601DateFormat the separator between the seconds and milliseconds has been changed to comma from full stop, in order to be compliant with ISO8601's preferred sign. Thanks to Jim Cakalic (jim_cakalic@na.biomerieux.com) for pointing out this discrepancy with the standard. [*] - Corrected a bug where RollingFileAppender would not work properly on Windows systems. Thanks to Heinz Richter (heinz.richter@ecmwf.int) for noting this problem. February 19, 2000 - Release of version 0.8.1. - Core classes are now independent of the format of the options file. Configurable core classes implement the OptionHandler interface. OptionHandlers allows configurators to learn the relevant option names. The configurator feeds option values to the OptionHandler which configures itself. As a result of these changes, the Init class has been broken down to two separate classes: the BasicConfigurator and the PropertiesConfigurator. [**] An XML configurator for 0.8.0 has been already written by Christopher Taylor (cstaylor@pacbell.net). - Added multiple appender support per category. The appenders follow the category hierarchy, i.e. a child category inherits the appenders of its parents. - Added an assert() method to the Category class. Steven Marcus (srnm@awaretechnologies.com) requested this addition. [*] - Atomatic stack printing is no longer supported. This was an unused and unreliable feature which unnecessarily complicated the code. [*] - log4j now emits a single warning message when no appender to write to could be found. This is typically the case when the user forgets to configure the log4j environment. This change was suggested by Jim Cakalic (jim_cakalic@na.biomerieux.com). [*] - RollingFileAppender adds file roll over capability--implemented by Heinz Richter (heinz.richter@ecmwf.int). [*] - Corrected a bug where a java.lang.NoClassDefFoundError would be thrown because com.ibm.log4j.helpers.SyslogTracerPrintWriter was not included in log4j.jar. Thanks to Jim Cakalic (jim_cakalic@na.biomerieux.com) for signaling this bug. [*] February 9, 2000 - Release of version 0.8.0. - There has been an important API changes. The Log, NOPLog and ILog classes have been removed. Their functionality has been migrated to the Category class. [***] In this release, instead of writing ILog.debug(CAT, "Some message."); one will write CAT.debug("Some message."); Arndt Schoenewald <arndt@ibm23093i821.mc.schoenewald.de> observed that one could use the Category objects directly for logging. - It is no longer possible to instantiate Category objects directly. Instead, one would use the factory method Category.getInstance(String name). [***] There category instantiation code was moved to CateogryFactory class. This class has package visibility and remains hidden from the user. This stylistic improvement was suggested by Luke Blanshard (luke@quiq.com). - The Init class offers methods to initialize the log4j environment. The Init.flagAsShippedCode method replaces the NOPLog class. - Changes in the documentation to reflect the API changes. - The NDC.cloneStack and inherit methods now tolerate null-stacks. [*] January 29, 2000 - Release of version 0.7.5. - TTCCLayout now takes a java.text.DateFormat object as a parameter. The task of formatting the date is delegated to this object. Added four classes extending the java.text.DateFormat class. These are RelativeTimeDateFormat, AbsoluteTimeDateFormat, DateTimeDateFormat and ISO8601DateFormat classes. Thanks to Arndt Schoenewald <arndt@ibm23093i821.mc.schoenewald.de> for suggesting the ISO8601 date format. These four classes can be parametrized with a particular TimeZone. The TTCCLayout class now accepts a new configuration file option called "TimeZone". These four DateFormats are less malleable than the java.text.SimpleDateFormat but they are also much faster. As a consequence of these changes, the setRelativeTime, setDatePrinting methods in TTCCLayout have been removed along with the associated configuration file options RelativeTime, DatePrinting and TimePrinting. [**] The current code is inspired by code contributed by Heinz Richter (heinz.richter@ecmwf.int). - The Log.emerg method has been deprecated. If you use statements of EMERG priority, please use the Log.log form instead. [**] - Added getDepth and setMaxdepth methods to the NDC class. This makes it easier to manage the nested context depth especially when callees push but forget to pop. - Moved the documentation in com/ibm/log4j/package.html to com/ibm/log4j/overview.html. Many users were failing to read the com/ibm/log4j/package.html description due to the unfortunate layout of the text. Hopefully more people will read the package overview in its present location. - Added the com.ibm.log4j.net package for doing remote logging using TCP sockets. This is still experimental code. - Added new debug, .., emerg methods that do not require a category parameter. They assume the "root" category, that is the decision to whether print or not is made by comparing the statement's priority with the default priority. [*] January 21, 2000 - Release of version 0.7.4. - Added a new ILog.init method accepting an Appender and a configuration file as parameters. - FileAppender's setWriter and setFile methods where not instantiating a new tracer. This caused stack traces to be lost! SyslogAppender had a similar problem. [*] - The FileAppender and SyslogAppender where not calling the layout's readConfig method to set layout specific options. Thanks to Heinz Richter (heinz.richter@ecmwf.int) for reporting this bug. [*] - Corrected a bug in Log.log() method where the appender was always called with Priority.DEBUG. Thanks to Oliver Boehm (Oliver.Boehm@abaxx.de) for reporting this bug. [*] January 14, 2000 - Release of version 0.7.3. - Added Syslog compatibility. One can now choose (at runtime) between remote syslog logging or file logging. [*] Syslog logging performance, although not appalling, is significantly slower than file logging. - Priority class was enriched with the previously missing priorities NOTICE, ALERT and CRIT. The internal constants were also aligned with the syslog counterparts. [*] - Added the Log.log method to support the new priorities. [*] - TracerPrintWriter is now an independent class instead of being a nested top-level class in Tracer. [*] - A number of writers, namely the SyslogWriter, SyslogQuietWriter, SyslogTracerPrintWriter, were added to the helper package. [*] - Log.force method was removed. The various Appender.doAppend implementations take over its functionality. [*] - FileAppender and SyslogAppender now use QuietWriter. QuietWriter is a FilterWriter which hides exceptions and instead emits a single warning message to System.err. [*] - The layout is now an initialization parameter to the appender type. Previously, the layout and the appender where independent parameters to the Log constructor. [**] - Many small improvements and corrections in the documentation. Syslog related documentation remains sparse. - ILog.init() and ILog.init(String configFile) have been changed to call ILog.init(,,,) with "com.ibm.log4j.Log.class" as the first parameter. This makes it easier for people to get familiar with log4j. [**] - Added missing files to the make directory. These files are useful for those wishing to use the log4j make environment. Thanks to "Lee Hall" <LHall@JavaFoundry.com> for reporting this omission. [*] Until recently the make environment failed to compile RMI stubs in a single run. This nagging problem has been corrected thanks to help from Thomas Eirich (IBM Zurich Research Lab). January 4, 2000 - Release of version 0.7.2. - Some users have been rightly complaining about the verbosity TTCCLayout's date output. The full date output is now shortened to "dd MMM YYYY HH:mm:ss.SSS" for example, "06 Nov 1994 08:49:37.459" In addition, users may now choose to print only time information, as in "08:49:37.459". [*] - The package now uses Writer instead of OutputStream as its output target. This makes the log4j code smaller and easier to understand at the cost of a slight performance degradation. As a result of this change a few method names in FileAppender class were changed. [**] - Preliminary experiments with SyslogAppedner and SyslogLayout show that syslog compatibility is not far away. The difficultly is adding syslog compatibility without making radical changes to the current log4j architecture. - Corrected a bug in the NOPLog.createInstance method which always created a Log singleton even if the system property "log4j.logType" was set to NOPLog. Thanks to Robert Gottofrey (Robert.Gottofrey@wdr.com) for reporting this bug and the associated test case. - Removed the inconsistent "Layout" configuration option in Log.readConfig(). This change should be transparent to most users. [*/**] December 20, 1999 - Release of version 0.7.1. - The LogCreationManager class has been removed. Its functionality has been transfered to the createInstance and getInstance methods in the Log and NOPLog classes. The new way of creating instances is both simpler and less error prone although just as flexible. [**] As a result of these changes, the init family of methods in the ILog class have been adjusted to the new way of creating the log singleton. - The Appender interface has been introduced. The method of writing a log statement into an output stream can now be varied by using a different Appender. The new FileAppender offers the same functionality that was previously part of the Log class. [**] - Changed the time format used in TTCCLayout to be of the form "Day, dd MMM YYYY HH:mm:ss.SSS GMT" for example, "Sun, 06 Nov 1994 22:49:37.459 GMT". This format is almost the same as the format specified in RFC 1123 and also the format recommended in RFC 2616. The only difference is the additional milliseconds information. [*] - The layout specific options were not read from the configuration file due to a missing instruction. Many thanks to Vikram Sridharan (Vikram.Sridharan@alysis.com) to patiently pointing out this omission to an unbelieving maintainer. [*] December 16, 1999 - Release of version 0.7.0. - Version 0.7.0 and above will be distributed under the IBM Public License (IPL). The IPL is an approved open source license (see http://www.opensource.org/licenses/ for a list). It grants similar rights to the previous ALPHAWORKS license agreement, in particular, the right to redistribute and to modify the package. - The Log class can now be parameterized with a Layout object. Layouts determine the format of what is printed, where as the Log class decides when to print and to where. [**] As a result of this modularization, the CGULog and NOPCGULog classes no longer exists. CGULog class has been replaced with the TTCCLayout (Time Thread Context Category). This should make it easier to create new log output formats. Some time in the near future, the Log class will be further broken down to allow different strategies for writing to output streams. - Renamed com.ibm.util.log hierarchy to to com.ibm.log4j. I wanted to do this for some time. I feel release 0.7.0 was the last opportunity to do so. I am sorry for the the trouble caused by this change. [**/***] - New NDC class. This class implements nested diagnostic contexts as suggested by Neil Harrison in the article "Patterns for Logging Diagnostic Messages" part of the book "Pattern Languages of Program Design 3" edited by Martin et al. Nested diagnostic contexts is a nifty feature that was missing up to now. [*] The StressNDC test class seems to break JDK 1.2.2 beta on AIX. On Linux and NT using sun's JDK 1.2.2 it seem to work OK. In any case, tests done with StressNDC and associated perl script seem to indicate that the NDC class is bug-free. - Corrected a date formatting bug in CGULog class where on some environments the wrong month was printed. Thanks to Christopher Williams (Christopher_Williams@mail.northgrum.com) for signaling this bug. Also changed the month format from a number to a three letter abbreviation such as "Jan", "Feb", ..., "Dec". The new format is unambiguous regardless of local date format. [*] December 8, 1999 - Release of version 0.6.2. - Clearer documentation with still much room for improvement. - Corrected a bug in the Tracer class which always used the Unix line separator instead of the system specific separator. Thanks to Vikram Sridharan (Vikram.Sridharan@alysis.com) for singaling this bug. [*] - Corrected a runaway comment which gulped the CGULog.readConfig method. [*] - Added the init family of methods to the ILog class to ease the setup of a basic logging environment. Thanks to Mark Donszelmann (Mark.Donszelmann@cern.ch) for this enhancement. [*] - Just an hour after releasing version 0.6.1 detected and corrected a bug where the Tracer class would correctly print Exception stack trace but not the type of the Exception. Replaced the distribution on www.zurich.ibm.com without changing the version number. I hope nobody is using the intermediary (and buggy) release of 0.6.1. [*] November 16, 1999 - Release of log4j version 0.6.1. - Better documentation with still much room for improvement. - For consistence sake, added setDefaultPriority and getDefaultPriority methods to the Category class and deprecated setDefaultPriority in the Log.class. [**] - Corrected a major bug where if two categories were homonyms the second instance would not be properly initialized. - Increased the speed of Exception logging from about 4000 microseconds to about 1000. It seems that for some people Exception logging is performance critical. Improved implementation is a variant of Nocolai's (XNH@crisplant.com) implementation. [*] November 9, 1999 - Release of log4j 0.6.0 with incomplete documentation. - Added a stress test program to debug the new Category class. It turns out that the test program was as hard to get right as the Category class. Given the favorable results of the stress test I am quite confident that the new class is now bug free. This assumption has been proven to be wrong. See above. - Created a new class called Category to manipulate categories instead of plain Strings. The new class is just as easy to use. However, the evaluation of whether to log or not to log is at least 10 times faster. The NOP class performance remain unaffected by the change. (You can't improve on the performance of an empty function call.) Many thanks to Alex Blewitt "Alex.Blewitt@ioshq.com" for his valuable comments. He was the first to observe that finding Strings in a hash table was an expensive operation. This change will require some recoding on your part. See the FAQ for more details. [***] - Modified the force in Log and CGULog method to use a byte[] buffer instead of a StringBuffer. The old code was clearer but the new one is at least 25% faster. [*] - Added regression testing. - We now enforce a policy where the OutputStream set by setOutputStream is a user managed resource whereas the OutputStream opened using setLogFile is the Log class' responsibility. The setLogFile method now closes any previous OutputStream if only if opened through setLogFile. If the previous OutputStream was opened by the user and set through setOutputStream the previous OutputStream is untouched. Similarly, setOutputStream will close any previous OutputStream if and only if it was opened using setLogFile. - Added a new method logOutputStreamExists to the Log class allowing the programmer to check if there is already an opened stream before trying to set a new one. A stream can be opened as a byproduct of reading the configuration file. - Changed the behavior of the (private) Log.Append method in case of failure to write to the OutputStream. Previously, in case of failure, we reverted to System.err. Now, we emit a warning message and discard all future log messages. The new behavior is consistent with our current unreliable logging semantics. The change prevents an otherwise functional program from failing because the terminal is flooded with logging messages. - Renamed the iLog to ILog to remain consistent with our class naming scheme. The initial intention was to add ILog and deprecate iLog. However, I am running CVS on a fat16 partition, causing serious problems when files differ only in case. - Corrected a bug where the LogFileName was not remembered. Thanks to Jens for signaling this bug. October 28, 1999 - Release of log4j v0.5a - Now the programmer can choose to truncate the log file instead of always appending to it. This functionality was first requested and intially implemented by "Jens Uwe Pipka" jens.pipka@gmx.de. [*] - setLogFile now opens the requested file instead of having the Append function open it later. Cleaned up some related code in the Append function. Although nobody has requested it, there is still no method to close the log file. This is harder to implement reliably than it sounds. [*] - Simplified setLogOutputStream so that it does no longer return the previously set OutputStream. [*] October 27, 1999 - Released log4j v0.5 - Joe Walker (joe@eireneh.com) observed that the LogCreationManager.getSingleton mechanism was cumbersome. There is now a new class iLog (indirect Log) which hides the need to call getSingleton. Performance testing on my 233Mhz Thinkpad shows that this indirection has small performance impact on non-logged calls in the order of 40 nanoseconds. The impact on logged calls is negligible. [*] - Added a jar file to the distribution. The jar file contains only the files you would need to use log but not other classes needed for testing nor examples. - Corrected a bug where CGUNOPLog was not integrated to the Makefile. - Added new public methods isDebugEnabled and isInfoEnabled to allow programmers to check whether a debug/info statement will be logged without incurring the cost of message parameter construction. This addition was suggested by Luke Blanshard Luke@quiq.com. [*] - Renamed the private method evaluate to isEnabled. Also made it final with no apparent speed gains. In addition, made the Log.force method public. [*] - New syntactic sugar debug, ..., emerg, methods to log objects. [*] - Modified the interface to deal with Throwables and not just Exceptions. My thanks to Luke Blanshard for signaling this "bug". [*] - Added more tests to the LogPerformance class. In particular, to test the influence of indirect debug calls. - Added a "make" mini-tutorial for those who want to modify the code. - License updated to standard alphaWorks license allowing modifications to source code. However, this license explicitly requires that modifications be communicated back to alphaWorks. October 15, 1999 - Initial availability on alphaWorks. Refer to the FAQ for the lineage of the package.