[Log4j] Install and Architecture

Install and Architecture

1. Install 

- http://logging.apache.org/log4j/1.2/download.html 

- To unzip the file and add a lib to java

2. Architecture

2_1. Core objects

- These are mandatory objects of the framework. They are required to use the framework

2_2. Support objects

- These are optional objects of the framework. They support core objects to perform additional but important tasks

3. Core Objects

3_1 . Logger Object

- The top-level layer is the Logger which provide the Logger object.

- The Logger object is responsible for capturing logging information and they are stored in a namespace hierarchy

3_2. Layout Object

- The layout layer provides objects which are used to format logging information in different styles

- It provides support to appender objects before publishing logging information

3_3. Appender Object

- This is a lower-level layer which provides Appender objects. The Appender object is responsible for publishing logging information to various preferred destinations such as a database, file, consol..