Log4J

Question 1

Log4J

Answer 1

A logging tool that helps us keep track of whats going on inside of code

Question 2

What outputs can Log4J send to?

Answer 2

Database
File
Console
UniSys Log

Question 3

Levels=> What to log

Answer 3

(Worst)
Fatal
Error
Warn
Info
Debug
Trace
(Least Bad)

Question 4

Appenders

Answer 4

Where to log

Question 5

Log4J Features

Answer 5

Thread safe
Multiple appenders support
Customization
High speed optimization
Various logging levels

Question 6

Advantages

Answer 6

quick debugging
easy maintenance
structured storage

Question 7

Disadvantages

Answer 7

slows down app

scrolling blindness

Question 8

Core Objects: Loggers

Answer 8

register the class to the logger
gathers the logging info and are captured in the namespace hierarchy

Question 9

Core Objects: Appenders

Answer 9

publishes the logging info to the respective destination(s)

lower level object

Question 10

Core Objects: Layouts

Answer 10

styling the logging information for readability

Question 11

Support Core Objects: Level

Answer 11

Defines granularity and priority of bugging info

Question 12

Support Core Objects: Filter

Answer 12

Analyse and decide whether to keep the logged info
Appenders can use multiple filters
Tell the appender whether or not to print the logs to the respective destination

Question 13

Support Core Objects: Object Renderer

Answer 13

Provides the string representation of the lagging information

Question 14

Support Core Objects: Log Manager

Answer 14

Reads configuration parameters