SLF4J (Simple Logging Facade for Java) provides support for a bridging legacy APIs as well as a source code migration tool.
SLF4J API offers an advanced abstraction of various logging systems, including JDK 1.4 logging, logback, and log4j. Features include MDC support and parameterized logging.
Furtheremore, logging systems can choose to implement the the SLF4J interfaces directly, e.g. logback or SimpleLogger.
In addition, you will be able to to write SLF4J adapters for a given API implementation, e.g. Log4jLoggerAdapter or JDK14LoggerAdapter.
· Java 1.5 or later
What's New in This Release: [ read full changelog ]
· The logger factories in most SLF4J modules namely in jcl-over-slf4j, log4j-over-slf4j, slf4j-jcl, slf4j-jdk14, slf4j-log4j12, and slf4j-simple now use a ConcurrentHashMap instead of a regular HashMap to cache logger instances. This change significantly improves logger retrieval times at the cost of some memory overhead. This improvement was requested in bug #298 by Taras Tielkes who also provided the relevant patch.