Answers for "log4j.properties example"

log4j2.properties example

#src/resources/log4j2.properties

status = warn

appender.console.type = Console
appender.console.name = LogToConsole
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n

#appender.file.type = File
#appender.file.name = LogToFile
#appender.file.fileName=logs/app.log
#appender.file.layout.type=PatternLayout
#appender.file.layout.pattern=[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n

# Rotate log file
appender.rolling.type = RollingFile
appender.rolling.name = LogToRollingFile
appender.rolling.fileName = logs/app.log
appender.rolling.filePattern = logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz
appender.rolling.layout.type = PatternLayout
appender.rolling.layout.pattern = %d %p %C{1.} [%t] %m%n
appender.rolling.policies.type = Policies
appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling.policies.size.size=10MB
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.max = 10

# Log to console and rolling file
logger.app.name = com.mkyong
logger.app.level = debug
logger.app.additivity = false
logger.app.appenderRef.rolling.ref = LogToRollingFile
logger.app.appenderRef.console.ref = LogToConsole

rootLogger.level = info
rootLogger.appenderRef.stdout.ref = LogToConsole

log4j.properties

# Root logger option
log4j.rootLogger=DEBUG, stdout, file

# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

# Redirect log messages to a log file, support file rolling.
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=C:\log4j-application.log
log4j.appender.file.MaxFileSize=5MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

how do you use log4j

How do you use Log4J in your framework?
Basically it is printing/logging the important
events of the application/test run.
in my project I did logging using the log4j library.
I added the library dependency into pom.xml.
For logging we create an object from
Logger Interface and LogManager class using
getLogger method and passing the class name in it;  

private static Logger log = LogManager.getLogger(LogDemo.class.getName());
static Logger log = Logger.getLogger(log4jExample.class.getName());

We create it by passing the
name of the current class.
Then we can use this object 
to do our logging.
log.info
log.debug
log.fatal
log.error

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

log4j example

# Define the root logger with appender file
log = /usr/home/log4j
log4j.rootLogger = DEBUG, FILE

# Define the file appender
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=${log}/log.out

# Define the layout for file appender
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.conversionPattern=%m%n