How to load multiple log4j configuration files?

In log4j, different configurations can be loaded by using multiple configuration files. Here is one way to do it:

1. Create a main configuration file, such as log4j.properties or log4j.xml, and define one or more appenders and loggers within it.
2. Include the information from the secondaryConfig.xml file.
3. Include the secondaryConfig.properties file.
4. Create additional configuration files, such as secondaryConfig.xml or secondaryConfig.properties, and define additional appenders and loggers within them.
5. During runtime, log4j will automatically load the main configuration file and then proceed to load other imported configuration files in order.

For example, here is a sample log4j.properties file:

# 主配置文件
log4j.rootLogger=INFO, console

# 输出到控制台的appender
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

# 导入其他配置文件
log4j.configuration=secondaryConfig.properties

Next, create a secondaryConfig.properties file to define additional appenders and loggers.

# 从主配置文件导入的配置
log4j.logger.com.example=INFO, file

# 输出到文件的appender
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=/path/to/logfile.log
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

In this way, log4j will first load the main configuration file, then based on the instructions in the main configuration file, load the secondaryConfig.properties file, and perform logging according to the defined appenders and loggers.