Some of the commonly used log4j configuration properties are described

1.ConsoleAppender Options
Threshold=warn: Specifies the lowest level of output for log messages.
Immediateflush=true: The default value is true, meaning that all messages will be immediately exported.
Target=system.err: By default: System.out, specify output console
2.FileAppender Options
Threshold=warn: Specifies the lowest level of output for log messages.
Immediateflush=true: The default value is true, meaning that all messages will be immediately exported.
File=mylog.txt: Specifies the message output to the Mylog.txt file.
Append=false: The default value is True, the message is incremented to the specified file, and false refers to overwriting the specified file contents with the message.
3.RollingFileAppender Options
Threshold=warn: Specifies the lowest level of output for log messages.
Immediateflush=true: The default value is true, meaning that all messages will be immediately exported.
File=mylog.txt: Specifies the message output to the Mylog.txt file.
Append=false: The default value is True, the message is incremented to the specified file, and false refers to overwriting the specified file contents with the message.
MAXFILESIZE=100KB: The suffix can be kb, MB, or GB. When the log file reaches that size, it scrolls automatically, moving the original content to the Mylog.log.1 file.
maxbackupindex=2: Specifies the maximum number of scrolling files that can be produced.
4.DailyRollingFileAppender Options
Threshold=warn: Specifies the lowest level of output for log messages.
Immediateflush=true: The default value is true, meaning that all messages will be immediately exported.
File=mylog.txt: Specifies the message output to the Mylog.txt file.
Append=false: The default value is True, the message is incremented to the specified file, and false refers to overwriting the specified file contents with the message.
Datepattern= '. ' YYYY-WW: Scrolls the file once a week, that is, a new file is generated each week. Of course, you can specify the month, week, day, time, and minutes. The corresponding format is as follows:
1) '. ' YYYY-MM: Monthly
2) '. ' YYYY-WW: Weekly
3) '. ' YYYY-MM-DD: Every day
4) '. ' Yyyy-mm-dd-a: two times a day
5) '. ' YYYY-MM-DD-HH: Per hour
6) '. ' YYYY-MM-DD-HH-MM: Per minute
5.PatternLayout Options
conversionpattern=%m%n: Specifies how to format the specified message.
6.HTMLLayout Options
Locationinfo=true: Default value is false, output Java file name and line number
Title=my app File: The default value is log4j Log Messages.
7.XMLLayout Options
Locationinfo=true: Default value is false, output Java file and line number