What is difference between log4j and Logback?
Log4j has been defined as java based application with logging utility which is the java framework for logging messages to a different output, which helps enable to locate the problems. Logback is defined as the successor to log4j, which is also a java framework for logging messages in any java based applications.
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.
Do we need SLF4J with log4j2?
We can directly use log4j2 without slf4j. But you are now locked to log4j2 library. So in future if you want to move to any other logging library. you have to go to all java files and change your logger statements.
Why do we need log4j?
Is log4j thread-safe?
Is log4j thread-safe? Yes, log4j is thread-safe. Log4j components are designed to be used in heavily multithreaded systems.
What is the difference between SLF4J and Log4j in Java?
As the name specified, SLF4J is a simple logging façade for java. It is not a logging component, and even it does not do the actual logging. It is only an abstraction layer to an underlying logging component. In the case of Log4j, it is a logging component, and it does the logging instructed to do.
Which is better for garbage collector SLF4J or log4j?
Since SLF4J uses less number of temporary strings means less work for the garbage collector, which means better throughput and performance for your application. So essentially, SLF4J does not replace log4j; they both work together.
Is the SLF4J compatible with all previous versions?
The Slf4j is compatible with all its previous versions. A user can easily migrate from slf4j to any version without any issue. There are several hindrances as one has to look after for the migration, talking of the Log4j2 the backward compatibility is not possible.
