Reputation: 53896
To log errors for a given class, I'm accessing the class name like so: Is this a 'good' way to return the class name as a String, so it can be used for logging?
private static final String CLASS_NAME = MyClass.class.getName();
logger.error("Error occurred in "+CLASS_NAME);
Upvotes: 16
Views: 40733
Reputation: 1608
I'm seeing a lot of people using external library, like log4j, slf4j, jboss.logger and so on...
I prefer the old way, using a simple
java.util.logging.Logger
It's standard and you don't need libraries to import.
You can initialize it as:
private static final Logger LOG = Logger.getLogger(A.class.getName());
and then each time the logger write on a stream know that you used the A class:
String errorcode = "ABC123";
LOG.log(Level.SEVERE,"This is a very important error with code {0}", new Object[]{errorcode});
whatever is you standard stream, for example a console or a logging file, it write something like:
[date] [hour] [level] [class] [description]
2020-01-01 00:00:10.123 SEVERE my.package.A This is a very important error with code AAA123
If you want a log customization, you can use java.util.logging.Handler.
At this link you can find an example of Handler.
Upvotes: 3
Reputation: 1445
I'd do it this way:
logger.error("Error occured in " + this.getClass().getName());
It's easier to mantain if something changes, but there are another ways to do this.
Upvotes: 2
Reputation: 31595
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.invoke.MethodHandles;
...
private final static Logger LOG =
LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
Upvotes: 23
Reputation: 6358
If you initialize the logger this way:
private static Logger logger = Logger.getLogger(MyClass.class.getName())>
then the name of the class will be present in every logging event, you don't need to explicitly put it in every log call:
logger.error("Error occured while doing this and that");
The you can configure the logging service (in logging.properties in case of java.util.logging
, or log4j.properties if you use Apache log4j) to include the class name in every log message.
Upvotes: 8
Reputation: 8014
You can set up your logging parameters in log4j.xml itself.
For exp -
<appender name="swcd-web" class="org.apache.log4j.DailyRollingFileAppender">
<param name="Threshold" value="DEBUG"/>
<param name="Append" value="true"/>
<param name="File" value="${catalina.home}/logs/swcd-web.log"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d [%t] %-5p %c - %m%n"/>
</layout>
</appender>
It would log exceptions like this in swcd-web.log file -
2012-05-23 16:34:51,632 [main] ERROR com.idc.sage.sso.dynamo.SsoDbStorage - cannot get configuration for max SSO age
Upvotes: 4
Reputation: 30578
Since you did not state which logging library you are using I suggest to use slf4j. I think it is the easiest you can get. You simply ask for a Logger object from slf4j's LoggerFactory
like this:
private static final Logger LOGGER = LoggerFactory.getLogger(YouerClass.class);
now you can use the LOGGER object for logging.
Logging an error for example looks like this:
LOGGER.error(yourMessage, throwable);
You can send a simple string message or the whole exception.
Upvotes: 1