In this article, we'll focus on the two most common logging implementations used for Tomcat - the included JULI implementation, and Log4J, a popular, feature-rich implementation compatible with JCL.Meet JULI - Java Utility Logging Implementation Although all JDKs ship with logging functionality provided by logging, this default implementation is not designed for container-based environments.Here's a rundown of the most common Tomcat logging frameworks, configurations, and concerns, to help you get started on adding a functional logging system to your administrative toolkit today.Tip: Logging, diagnostics, error-free deployment, and advanced application provisioning can be done for your entire Tomcat infrastructure all in one console. An Overview of Tomcat Logging As of Tomcat 5.5, Apache's Java Commons Logging (JCL) technology is used throughout Tomcat.If you are a technical support provider, the supervisors/pay reps in your department can tell you if Kronos Full (Java) is important to them.The following functionality is not available in HTML Kronos: Top Always use the 32-bit Java. Top Oracle Corporation releases Java updates four times a year.Top Starting with Java 7 update 51, you can "white list" trusted websites in Java security either via the Java Control Panel (useful for end users) or via exception file (useful for managed environments).
You probably already have implemented logging in your web applications, and may not see why you should worry about configuring loggers for Tomcat's internals.
JCL is a lightweight API for Java applications that allows hierarchical logging to be supported across all log levels, independent of logging implementation.
This means that rather being limited to a specific hard-coded framework, you can choose the solution that works for you with only a small amount of extra configuration.
To get around this limitation, Tomcat replaces the default Log Manager with JULI, a modified implementation with a number of additional features for handling containers.
The most notable of JULI's extended functionalities is the ability to set property files on a per-classloader basis.