如何为不同的附加程序配置log4j

Question

I tried to configure log4j.properties for different output layer.

For example:

• show at console only WARN level.
• write INFO level to log file.

I tried to find right solution. I found that when you write some info level about your desired package as:

log4j.logger.your.package.name=DEBUG

It prints debug loggers to console and file.

Here content of log4j.properties :

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

# Direct log messages to stdout
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{ABSOLUTE} %5p %t %c{1}:%M:%L - %m%n 

# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.file=logs/myapp_test.log
log4j.appender.file.MaxFileSize=2MB
log4j.appender.file.MaxBackupIndex=1
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.conversionPattern=%d{ABSOLUTE} %5p %t %c{1}:%M:%L - %m%n 

log4j.logger.com.my.lab=DEBUG

• How to configure different output layer for file and console?

Answer 1

You can set different logging level for File & Console Appender as

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

# Direct log messages to stdout
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{ABSOLUTE} %5p %t %c{1}:%M:%L - %m%n 

# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.file=logs/myapp_test.log
log4j.appender.file.MaxFileSize=2MB
log4j.appender.file.MaxBackupIndex=1
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.conversionPattern=%d{ABSOLUTE} %5p %t %c{1}:%M:%L - %m%n 


# Set the logger level of Console Appender to WARN
log4j.appender.stdout.Threshold = WARN

also refer this link

Answer 2

You can define a threshold:

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

# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Threshold = WARN
log4j.appender.stdout.target=System.out 
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.conversionPattern=%d{ABSOLUTE} %5p %t %c{1}:%M:%L - %m%n 

# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.file=logs/myapp_test.log
log4j.appender.file.MaxFileSize=2MB
log4j.appender.file.MaxBackupIndex=1
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.conversionPattern=%d{ABSOLUTE} %5p %t %c{1}:%M:%L - %m%n 

log4j.logger.com.my.lab=DEBUG