SLF4J News

You can receive SLF4J and NLOG4J related announcements by subscribing to the SLF4J announce mailing list.


March 8th, 2006 - Release of SLF4J 1.0

This is release labeled as 1.0 (final) contains few relatively minor changes:


February 4th, 2006 - Release of SLF4J 1.0-RC6 and NLOG4J 1.2.22

The MarkingLogger interface has been removed and its contents merged into org.slf4j.Logger. This change should not adversely affect end-users. However, SLF4J bindings need to be updated. This has been done for all the bindings shipped with SLF4J distribution as well as NLOG4J. As for x4juli, the update is planned for its next release.

The merge between the MarkingLogger and Logger interfaces has been motivated by the need to allow end-users to easily switch between logging systems that support markers and those that do not.

Added a default instance to SimpleLoggerFactory to serve as a last resort fallback mechanism. This instance is designed to be used by a very specific group of users, namely for those developing logging systems (e.g. log4j or LOGBack). It is not intended for end-users of the SLF4J API.


January 9th, 2006 - Release of SLF4J 1.0-RC5 and NLOG4J 1.2.21

A maintenance release correcting bugs #11 and #12 and in general improved resilience to null input parameters across implementations. Many thanks to Boris Unckel and Kenneth for reporting the null input issue.


December 27th, 2005 - Release of SLF4J 1.0-RC4 and NLOG4J 1.2.20

The printing methods in org.slf4j.Logger interface now support passing 3 or more parameters in an Object array. This was a frequently requested feature missing in previous versions of SLF4J.

NLOG4J 1.2.20 reflects the addition of new methods in the org.slf4j.Logger interface.


December 8th, 2005 - Release of SLF4J 1.0-RC3

Maintenance release fixing reported bugs #6 and #7.

November 28th, 2005 - Release of SLF4J 1.0-RC2

In response to a request by Greg Wilkins, this release adds the jar file slf4j-jcl.jar, an SLF4J binding for JCL. Please read the gradual migration section in the manual for more details.


November 21st, 2005 - Release of SLF4J 1.0-RC1

A maintenance release correcting bugs #4 and #5. Many thanks to Christian Beil for accurately reporting bug #4.

There has been also an effort to minimize the file sizes of the various jar files produced by SLF4J, resulting in jar files approximately 40% smaller than in version 1.0beta9.

Given that the SLF4J API is now deemed stable, this release is marked as RC1, that is release candidate number 1.


October 19th, 2005 - Release of SLF4J 1.0-beta9

The SLF4J distribution now includes two distinct bindings slf4j-log4j12.jar and slf4j-log4j13.jar in order to differentiate between log4j version 1.2 and version 1.3. This distinction is absolutely necessary because log4j 1.2 and 1.3 are not run-time compatible, although they are mostly compile-time compatible.


October 19th, 2005 - Release of SLF4J 1.0-beta8 and NLOG4J 1.2.18

Added a new SLF4J binding, slf4j-log4j.jar, intended to be used in conjunction with vanilla log4j.jar, as distributed by the Apache Logging Services project. The slf4j-log4j binding is quite similar in structure to the JDK 1.4 binding that existed previously.

The slf4j-log4j binding addresses compatibility problems which arose when copies of both log4j.jar and nlog4j.jar lay on the class path, in particular when it was undesirable or impossible to remove the preexisting log4j.jar file.

Methods in the org.slf4j.Logger interface related to markers were moved to a separate super interface called org.slf4j.MarkingLogger. This refactoring reduces the weight of the Logger interface.


August 28th, 2005 - Release of SLF4J 1.0-beta7 and NLOG4J 1.2.17

Spurred by bug report #3, SLF4J binding code has been refactored and simplified. Logging systems implementing SLF4J interfaces have to have less work in order to bind with SLF4J. Moreover, these changes have no incidence on the published interface of SLF4J.


August 26th, 2005 - Release of SLF4J 1.0-beta6

To ease migration to SLF4J from JCL, this release includes a jar file called jcl-over-slf4j-1.0.4.jar. This jar file can be used as drop-in replacement for JCL version 1.0.4. It implements the public API of JCL using SLF4J underneath.

Thus, you can immediately benefit from the advantages of SLF4J without waiting for all the libraries you depend on to migrate to SLF4J first.


August 16th, 2005 - Release of NLOG4J 1.2.16

This release adds solves a compatibility problem between log4j and nlog4j. Previous to this release, code compiled with log4j would not run correctly with nlog4j.

With the fixes introduced in NLOG4J 1.2.16, code compiled with log4j 1.2.x will run without problems when deployed using NLOG4j.

However, the inverse is not true. Code compiled with nlog4j can only be deployed using nlog4j.


August 12th, 2005 - Release of SLF4J 1.0-beta5 and NLOG4J 1.2.15

This release adds support for the Marker interface. Thus, log statements can be decorated with Marker data allowing more expressive power in the processing of log statements.

For the sake of IoC frameworks, Logger instances can new be queried for their name.

With the addition of markers, sub-domains are no longer needed.

The LoggerFactoryAdapter has been simplified and renamed as ILoggerFactory.


July 5th, 2005 - Release of NLOG4J 1.2.14

This release fixes compatibility problems between NLOG4J and Jakarta Commons Logging.


June 28th, 2005 - Release of SLF4J 1.0-beta4 and NLOG4J 1.2.13

Following discussions on the SLF4J developers list, the signatures of the printing methods in org.slf4j.Logger interface have been modified to admit messages of type String instead of type Object as previously. The current set of printing methods is listed below.

 void debug(String msg); 
 void debug(String format, Object arg); 
 void debug(String format, Object arg1, Object arg2); 
 void debug(String msg, Throwable t); 

 void error(String msg); 
 void error(String format, Object arg;) 
 void error(String format, Object arg1, Object arg2); 
 void error(String msg, Throwable t); 
      
 void info(String msg); 
 void info(String format, Object arg); 
 void info(String format, Object arg1, Object arg2); 
 void info(String msg, Throwable t); 
      
 void warn(String msg); 
 void warn(String format, Object arg); 
 void warn(String format, Object arg1, Object arg2); 
 void warn(String msg, Throwable t);  

NLOG4J release 1.2.13 reflects changes in the SLF4J API.

You can download SLF4J and NLOG4J, including full source code, class files and documentation on our download page.


May 17th, 2005 - SLF4J version 1.0-beta-3 released

In response to user comments, the org.slf4j.ULogger interface has been renamed as org.slf4j.Logger.


May 17th, 2005 - NLOG4J version 1.2.12 released

SLF4J.ORG is proud to release NLOG4J 1.2.12, a log4j-replacement with native SLF4J API support. Except for users of LF5, chainsaw or NTEvenAppender, NLOG4J should be considered as a 100% compatible, drop-in replacement for log4j version 1.2.9.

This release reflects changes in the SLF4J API, i.e renaming of org.slf4j.ULogger interface as org.slf4j.Logger.


May 17th, 2005 - SLF4J version 1.0-beta-3 released

SLF4J.ORG is proud to release SLF4J 1.0-beta-3. In response to user comments, the org.slf4j.ULogger interface has been renamed as org.slf4j.Logger.

You can download SLF4J, including full source code, class files and documentation on our download page.


May 14th, 2005 - NLOG4J version 1.2.11 released

SLF4J.ORG is proud to release NLOG4J 1.2.11, a log4j-replacement with native SLF4J API support. Except for users of LF5, chainsaw or NTEvenAppender, NLOG4J should be considered as a 100% compatible, drop-in replacement for log4j version 1.2.9.

You can download NLOG4J version 1.2.11, including full source code, class files and documentation on our download page.


May 4th, 2005 - SLF4J version 1.0-beta-2 released

SLF4J.ORG is proud to release SLF4J 1.0-beta-2. This release contains cosmetic or javadoc changes. For example, the project has a new logo.

You can download SLF4J version 1.0-beta2, including full source code, class files and documentation on our download page.


1 May 2005 - not-log4j-1.2.10 released

Subsequent to the recall of log4j 1.2.10, SLF4J.ORG releases non-log4j-1.2.10 for those interested in SLF4J support in log4j.

You can download not-log4j version 1.2.10, including full source code, class files and documentation on our download page.


22 April 2005 - SLF4J project goes live

The SLF4J project site, including SVN repositories go live. Users can download SLF4J version 1.0-beta1.


15 April 2005 - start of work on SLF4J source code

Start of work on the SLF4j source code.


13 April 2005 - start of work on SLF4J project

Launch of the SLF4J project. Work has begun on the web-site, svn repositories as well as the source code.