Should I use log4j or SLF4J?
Best practice is to use slf4j to for your own log statements, and then choose the appropriate backend for it (including log4j as well by configuring to use log4j as a logging backend). Now all you have to choose, which logging framework you need to use in runtime.
How do you use log4j and SLF4J together?
If you want to use slf4j and log4j , you need these jar files on your classpath:
- slf4j-api-1.6. jar.
- slf4j-log4j12-1.6. jar.
- log4j-1.2. jar.
Why do we need SLF4J?
This is the main purpose of SLF4J (Simple Logging Facade for Java) – a logging abstraction which helps to decouple your application from the underlying logger by allowing it to be plugged in – at runtime. Of course, the flexibility that such an abstraction provides is the main reason to use SLF4J.
Why do we need log4j?
log4j is a tool to help the programmer output log statements to a variety of output targets. In case of problems with an application, it is helpful to enable logging so that the problem can be located. With log4j it is possible to enable logging at runtime without modifying the application binary.
Can I use both log4j and Logback?
As the slf4j documentation says, you just have to replace all the log4j dependencies with a single one from slf4j, named log4j-over-slf4j: http://slf4j.org/legacy.html#log4j-over-slf4j. Any code that is under your direct control can just use slf4j + logback as it always would.
Is log4j2 better than Logback?
Key Difference Between Log4j vs Logback
Better versions: When we compare versions of log4j and logback, then log4j is better than logback versions less than 1.2. 1. As logback is improved, version log4j and versions log4j2 and logback have no difference in terms of performance or any features.
What is logger in Java?
A Logger object is used to log messages for a specific system or application component. Loggers are normally named, using a hierarchical dot-separated namespace. Logger names can be arbitrary strings, but they should normally be based on the package name or class name of the logged component, such as java.net or javax.
What are the log levels?
Understanding logging levels
What is difference between Log4j and log4j2?
Community support: Log4j 1. x is not actively maintained, whereas Log4j 2 has an active community where questions are answered, features are added and bugs are fixed. Automatically reload its configuration upon modification without losing log events while reconfiguring.