Log4j：如何编写配置？

Question

I added Log4j2 to the project, and added config.

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

# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=C:\\logging.log
log4j.appender.file.MaxFileSize=10MB
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

# 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{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

Than, I log code like here:

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

...

final static Logger logger = LogManager.getLogger(AbstractEditor.class);

...

logger.info("updated: " + entity);
logger.debug("==> debug");
logger.info("==> info");
logger.warn("==> warn");
logger.error("==> error");
logger.fatal("==> fatal");
logger.trace("==> trace");

As I understand, all logs with level higher than DEBUG must be written to console and file. But only this has been printed into console:

15:08:52.285 [http-nio-8080-exec-1] ERROR ru.example.AbstractEditor - ==> error
15:08:52.292 [http-nio-8080-exec-1] FATAL ru.example.AbstractEditor - ==> fatal

I see this strings not matches my config. And they are not witten into file. When I added this config, all logs disappeared from console, excluding this 2 strings.

Please help to write config to see all logs with level from DEBUG on console and file.

Answer 1

You are programmatically using Log4j 2 but using the configuration format of Log4j 1. Log4j 2 is ignoring your configuration and using the default. You have 2 choices.

1. Convert your configuration to use Log4j 2 syntax (recommended), or
2. Enable Log4j 2's experimental support for log4j 1 configuration files by setting the system property "log4j1.compatibility=true". This support was added in release 2.13.0 so you would have to be using that version. The property file would also have to be named log4j.properties, not log4j2.properties.