SLF4J GudangMovies21 Rebahinxxi LK21

Simple Logging Facade for Java (SLF4J) provides a Java logging API by means of a simple facade pattern. The underlying logging backend is determined at runtime by adding the desired binding to the classpath and may be the standard Sun Java logging package java.util.logging, Log4j, Reload4j, Logback or tinylog.
The separation of the client API from the logging backend reduces the coupling between an application and any particular logging framework. This can make it easier to integrate with existing or third-party code or to deliver code into other projects that have already made a choice of logging backend.
SLF4J was created by Ceki Gülcü as a more reliable alternative to Jakarta Commons Logging framework. Research in 2013 on 10,000 GitHub projects found that the most popular Java library is SLF4J, along with JUnit, with 30.7% of projects using it. In January 2021, it was ranked as the second most popular project according to mvnrepository.




Similarities and differences with log4j 1.x


Five of log4j's six logging levels are used (ERROR, WARN, INFO, DEBUG, TRACE). FATAL has been dropped on the basis that inside the logging framework is not the place to decide when an application should terminate and therefore there is no difference between ERROR and FATAL from the logger's point of view. In addition, SLF4J markers offer a more general method for tagging log statements. For example, any log statement of level ERROR can be tagged with the "FATAL" marker.
Logger instances are created via the LoggerFactory, which is very similar in log4j. For example,
In Logger, the logging methods are overloaded with forms that accept one, two or more values. Occurrences of the simple pattern {} in the log message are replaced in turn with the values. This is simple to use yet provides a performance benefit when the values have expensive toString() methods. When logging is disabled at the given level, the logging framework does not need to evaluate the string representation of the values, or construct a log message string that is never actually logged. In the following example, string concatenation and toString() method for the values count or userAccountList are performed only when DEBUG is enabled.

Similar methods exist in Logger for isDebugEnabled() etc. to allow more complex logging calls to be wrapped so that they are disabled when the corresponding level is disabled, avoiding unnecessary processing.
Unlike log4j, SLF4J offers logging methods that accept markers. These are special objects that enrich the log messages. At present time, logback is the only framework which makes use of markers.




Similarities and differences with log4j 2.x


Apache log4j 2.x supports all slf4j features.




Version history






= Version 2

=
Version 2.0.0 was released on 2022-08-20. The latest version 2 release is 2.0.9 (2023-09-03).
Significant changes and feature additions:

Support for lambda syntax in passing messages to be logged.
Addition of a Fluent API.
Requires Java 8 or later.




= Version 1

=
Version details can be found in the manual.
Significant versions include:

Version 1.7.36 and all newer releases are reproducible.
Version 1.7.35 slf4j-log4j12 module is replaced by slf4j-reload4j.
Version 1.7.33 adds support for reload4j via the slf4j-reload4j module. It is the latest stable release. See Download product page.
Version 1.7.5 yielded significant improvement in logger retrieval times.
Version 1.7.0 added support for varargs, requiring support for Java 5 or later.
Version 1.6 brought a no-operation implementation used by default if no binding found.
Version 1.1 releases in Maven repositories began 2006-09.




See also



Java logging framework




References






External links


Official website

Kata Kunci Pencarian:

• SLF4J
• Java logging framework
• JUnit
• Log4j
• List of Java frameworks
• NEXEN (platform)

6 minute SLF4J tutorial for the beginner (2013-06) - YouTube

SLF4J Documentation

SLF4J

SLF4J

SLF4J: Class path contains multiple SLF4J bindings.SLF4J: Actual ...

"SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions ...

"SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions ...

SLF4J Tutorial

SLF4J Vs Log4j

SLF4J: Class path contains multiple SLF4J bindings. | ProgrammerAH

SLF4J: Class path contains multiple SLF4J bindings. | ProgrammerAH

A word on recent Slf4j and Spring incompatibility - ZONE 84

slf4j

Daftar Isi

• What is the difference between Log4j, SLF4J and Logback?
• java - Using @Slf4j annotation for logging - Stack Overflow
• java - Is it worth to use slf4j with log4j2 - Stack Overflow
• java - How to configure slf4j-simple - Stack Overflow
• java - How to programmatically setup slf4j logger with ...
• Logger slf4j advantages of formatting with {} instead of string ...
• java - How to change slf4j logging level - Stack Overflow
• Found slf4j-api dependency but no providers were found
• Setting log level of message at runtime in slf4j
• What is the best way to unit-test SLF4J log messages?

What is the difference between Log4j, SLF4J and Logback?

Sep 18, 2016 · Log4j 2 is somewhat comparable to Logback+SLF4J, in that it provides a facade API (log4j-api, comparable to SLF4J) as well as an implementation (log4j-core, comparable to Logback). If the above seems to contradict other sources, that may be because Log4j version 1 was very different and remains in use, so sources describing "Log4j" may in fact ...

java - Using @Slf4j annotation for logging - Stack Overflow

Aug 28, 2021 · @Slf4j The above annotation from lombok creates a slf4j based Logger, but you would be requiring a log4j based logger. So don't feel you could use slf4j based logger. If you plan to user slf4j based logger, lombok modifies the code and creates code during the compile phase not during runtime like cglib or using reflections. This would mean ...

java - Is it worth to use slf4j with log4j2 - Stack Overflow

Jan 8, 2017 · SLF4J is still your safety valve, it just doesn't mean your application should code against the SLF4J API anymore. Disclosure: I contribute to Log4j2. Update: There seems to be some confusion that programming to the Log4j2 API somehow introduces a "facade for a facade".

java - How to configure slf4j-simple - Stack Overflow

Jan 27, 2013 · I ran into a situation where I was using a library that logged to slf4j - and I was using the library while writing a maven mojo plugin. Maven uses a (hacked) version of the slf4j SimpleLogger, and I was unable to get my plugin code to reroute its logging to something like log4j, which I could control. And I can't change the maven logging config.

java - How to programmatically setup slf4j logger with ...

SLF4JBridgeHandler is a java.util.logging (JUL) logging bridge, which will "intercept" the JUL logging statements and route them to the SLF4J. Other bridges available are jcl-over-slf4j (Jakarta Commons Logging => SL4J) and log4j-over-slf4j (Log4J => SL4J) (as well as …

Logger slf4j advantages of formatting with {} instead of string ...

May 11, 2012 · (Before SLF4J 1.7) But only two parameters are possible. Because the vast majority of logging statements have 2 or fewer parameters, SLF4J API up to version 1.6 covers (only) the majority of use cases. The API designers have provided overloaded methods with varargs parameters since API version 1.7.

java - How to change slf4j logging level - Stack Overflow

Sep 5, 2017 · I'm using the org.slf4j.Logger in a Java EJB-Project running on a glassfish 3.1.2 server. import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class main { private static final Logger

Found slf4j-api dependency but no providers were found

You may add either of the following dependencies: Placing one (and only one) of slf4j-nop.jar slf4j-simple.jar, slf4j-log4j12.jar, slf4j-jdk14.jar or logback-classic.jar on the class path should solve the problem

Setting log level of message at runtime in slf4j

Apr 12, 2010 · The fluent API in SLF4J v2.0 introduces a new method, namely Logger.atLevel(Level) which an be used to accomplish the desired outcome. Example code: public void logAMessageAtGivenLevel(Level aLevel, String aMessage) { Logger logger = .. // some slf4j logger of choice logger.atLevel(aLevel).log(aMessage); }

What is the best way to unit-test SLF4J log messages?

Jan 10, 2011 · Instead of mocking SLF4J you could place the important logging calls you need to test inside their own methods which you can mock more easily. If you really want to mock SLF4J, I would bet you could create your own provider for it that would allow you to supply a mock logger from the SLF4J side instead of injecting one in your service objects.