"Fine-grained Control Over Logs Log interception is just one approach to application instrumentation. The advantage of log interception is that it is real-time, simple, pure Java—and relatively lightweight. With so few classes or extra processing, it is a production-friendly approach. By leveraging log4j you have fine-grained control over which logs get processed and at which level. Measurement can be turned on and off with one line of configuration."
"Log4j is a popular logging package written in Java. One of its distinctive features includes the notion of inheritance in categories. Using a category hierarchy, it is possible to control which log statements are output at arbitrary granularity, thus reducing the volume of logged output and minimizing the cost of logging."
"Figure 3 shows the IMAppender usage scenario: A log4j application configured to use IMAppender logs its debugging data wrapped as an IM message. The instant message is routed over the Jabber company-wide network to the system administrator's Jabber address (notice that publicly available Jabber servers might not be reliable enough for production use). Thus, whenever system administrators need to check on the application's status, they simply load their favorite Jabber client and connect to the Jabber server. As the figure shows, the administrator can be reached through different devices. He may log in to the server using his PC at work, or when he is away from his desk, he may use a Jabber client running on a handheld device to check messages."
"Log4j is an OpenSource logging API developed under the Jakarta Apache project. It provides a robust, reliable, fully configurable, easily extendible, and easy to implement framework for logging Java applications for debugging and monitoring purposes. Log4j allows developers to insert log statements in their code and configure them externally. This article covers the need for logging; a brief introduction to log4j; an explanation of its components and terminology, implementation, and configuration; its advantages and shortcomings; and how to use it to log Java applications."
