Home » Introduction to Log4j

Introduction to Log4j

by Online Tutorials Library

Introduction to Log4j


Logging is a powerful aid for understanding and debugging the runtime behavior of the programs. Simply the logging means some way to indicate the state of the system at runtime. Logs are used to capture and persists the important data and make it available for analysis at any point in time.

Good logging requires three things:

  • The log messages have to provide the required information to understand what the application does internally.
  • Writing log messages have to be as efficient as possible so that it does not affect the performance of your application.
  • You need to be able to adapt the logging details to different deployment environments and situations

Advantages of Logging

Almost all software development projects can run on a proper and strict schedule. Logging for an application can offer the following benefits:

Quick Debugging: Once we diagnose the problem, we know exactly how to solve the problem. Well-planned and well-written logging code reduces the overall cost of debugging the application.

Problem Diagnosis: No matter how well written our code is, there may be some problems hidden in it. If you review the logging process, then we will be able to detect the problems precisely and quickly.

Easy Maintenance: Application with a useful logging feature is easy to debug, and therefore, it is easy to maintain.

Cost and Time Savings: Well-written logging code offers quick debugging and easy maintenance. It makes installation, day to day maintenance, and maintenance, and debugging much more cost and time-effective.

Disadvantages of Logging

Following disadvantages can occur with any logging process:

  • Logging adds runtime overhead due to the generation of logging information and the device Input/Output (I/O) related to publishing logging information.
  • Logging includes programming overhead due to the extra code required for producing logging information. The logging process increases the size of the code.
  • Badly produced logging information can cause confusion.
  • Logging with bad code can seriously affect the application’s performance.
  • Last but not least, logging requires planning ahead, as adding logging code at a late stage of development is difficult.

Various logging frameworks are available in java such as SLF4J and Log4J. Apache Log4j is a very popular and old logging framework. It is a reliable, flexible, and fast logging framework or APIs are written in Java developed in early 1996. It is distributed under the Apache software license. Log4J has been ported to the Python, Perl, and C, C++, C #, Ruby and Eiffel languages. This tool is used for small to large scale Selenium Automation projects.

Log4j views the logging process in levels of priorities and to offer mechanisms to direct logging information to a great variety of destinations, such as a console, database, file, UNIX Syslog, etc.

Why use Log4j?

  • It is an open source.
  • With log4j, it is possible to store the flow details of our automation in a file or database.
  • Log4j is worked for large as well as small projects.
  • In log4j, we use log statements rather than SOPL statements in the code to know the condition of a project while it is executing.

Log4J Features

  • It is thread-safe
  • It is optimized for speed
  • It is based on a named logger hierarchy
  • It supports internationalization
  • It supports multiple outputs of appenders per logger
  • It is not restricted to a predefined set of facilities
  • The format of the log output can be easily altered by extending the Layout class
  • It is designed to manage Java exceptions from the start
  • Behavior of logging can be set at runtime using a configuration file

You may also like