Java Logging API usage

When you are developing a program, debugging (debugging) and logging are very important tasks. However, there are too many logging APIs available because they are both good, it is difficult to make a choice. the foreign java Forum also has some discussions on these logging methods.
While common logging is a small bridge between these different logging APIs. currently, the most famous Log method in Java is Log4j and JDK 1.4 Logging API. in addition, there are LogKit and so on used in aveon. commons-logging also implements some basic logging methods: NoOpLog and SimpleLog. their comparison is not in the scope of this discussion,
If you are interested, please refer to the reference file.
The quick use of Logging is actually very simple to use, put the commons-logging.jar under/WEB-INF/lib. Then write the following code
LoggingTest. java
Package com. softleader. newspaper. java. opensource;
Import org. apache. commons. logging. Log;
Import org. apache. commons. logging. LogFactory;
Public class LoggingTest {
Log log = LogFactory. getLog (LoggingTest. class );
Public void hello (){
Log. error ("ERROR ");
Log. debug ("DEBUG ");
Log. warn ("WARN ");
Log.info ("INFO ");
Log. trace ("TRACE ");
System. out. println ("OKOK ");
}
}
Place a jsp test test-commons-logging.jsp/
<% @ Page import = "com. softleader. newspaper. java. opensource. LoggingTest" %>
<% LoggingTest test = new LoggingTest (); test. hello (); %>
You will see the following output in the tomcat console
Log4j: WARN No appenders cocould be found for logger (com. softleader. newspaper. java. opensource. LoggingTest ).
Log4j: WARN Please initialize the log4j system properly. OKOK