SPRINGMVC Project Complete Example 05th log--log4j

Log4j

is log for Java, foreigners like this, such as the i18n---internationalization is not between I and N have 18 letters ...

http://logging.apache.org/log4j/2.x/

Straight into the chase.

He is a powerful Japanese functional component

Want to use him, the elephant in the refrigerator as much as the root

1. Download a jar package and put it in the project

2, make a configuration file (can be used before the direct copy in order to modify it)

Say simple words, very simple, but said configuration, in fact, is quite a lot, after all, powerful

Now my configuration file

### set log levels ###
log4j.rootLogger = DEBUG,stdout
 
 
### 输出到控制台 ###
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 = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
 
 
### sql ###
log4j.logger.java.sql.PreparedStatement=DEBUG 
log4j.logger.java.sql.ResultSet=DEBUG

See the use of a test case

Our previous Testuserservice.java.

I did three things.

1,import

2, defining variables

3, using

Run this use case

Let's take a look at the output

Note that:

Logger.debug (Object message);  Logger.info (Object message);  Logger.warn (Object message);  Logger.error (Object message);

He has several methods, huh?

In fact, you can put me this paragraph, directly copied paste in the past, if necessary, such as modifying the file log to save the path, a little modification can be, the following specific said configuration file may not look ....

src同级创建并设置log4j.properties
# # # # # # #下面的才是正文, this sentence and the above please do not copy #####

 
 ### 设置###
log4j.rootLogger = debug,stdout,D,E
 
### 输出信息到控制抬 ###
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 = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
 
### 输出DEBUG 级别以上的日志到=E://logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = E://logs/log.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG 
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
 
### 输出ERROR 级别以上的日志到=E://logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =E://logs/error.log 
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR 
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n

For example, if we add this paragraph

It's the way it works.

SPRINGMVC Project Complete Example 05th log--log4j