Introduction of log4j specific level and output information configuration method

LOG4J has a total of 5 log output levels:

FATAL (0) <error (3) <warn (4) <info (6) DEBUG < (7)

Example:

Log4j.rootlogger=debug,console, File
The above settings can crawl throw new RuntimeException ();
Log4j.rootlogger=info,console, File
Info level can not catch throw new RuntimeException ();

The reason is that this error belongs to the DEBUG level debug>info>error so INFO can't catch it.

Console output log information configuration, such as:

Modify the Log4j.properties log level, the general error is sure to output, there is a warning message warn:log4j.rootlogger=warn  can be.