问题
My Java EE 6 application uses slf4j with logback as logging framework. Now I want to add the SQL traces of OpenJpa to my log files. The OpenJpa-Documentation says, I can use a parameter to this:
<property name="openjpa.Log" value="slf4j"/>
I use the WebSphere Application Server v8.0.0.1 as Java EE container. If I deploy my application to the server, this parameter does not change anything. I can change log levels in WebSphere Admin Console and this works fine. But a cannot bypass the OpenJpa logging to my slf4j framework.
Does anyone uses such configuration and solved the problem?
Btw. I know, that the InformationCenter-Article http://publib.boulder.ibm.com/infocenter/wasinfo/v8r0/index.jsp?topic=%2Fcom.ibm.websphere.nd.doc%2Finfo%2Fae%2Fae%2Ftejb_jpatroubleshoot.html says, that the parameter will be ignored, but everything should be possible, eh?
回答1:
I don't know what version of OpenJPA is embedded in WAS 8.0.
In OpenJPA 1.x there was no possibility to use "slf4j". A workaround was copying the class org.apache.openjpa.lib.log.SLF4JLogFactory from OpenJPA 2.x sources to your application and using it directly:
<property name="openjpa.Log" value="org.apache.openjpa.lib.log.SLF4JLogFactory"/>
You can always specify the factory class name directly, the short name is only a convenience trick.
In OpenJPA 2.x the SLF4JLogFactory is present, so it should work with your current settings; perhaps you set it in a place that is overridden by other configuration? For example, if you configure JPA through EntityManagerFactory's propertyMap, it takes precedence over the settings in persistence.xml.
回答2:
I solved it.
There are four things to do:
- Say that OpenJpa logs the statements. That is done by the property entry in the persistence.xml.
- Say Slf4j that it has to fetch the logs from JUL too. This can be done by installing the SLF4JBridgeHandler by SLF4J. I installed the bridge via a ServletContextListener which is called at application start.
- Configure Logback that it does not log ALL logs from JUL but only the needed Logs. This is done by adding the LevelChangePropagator in the logBack-test.xml
- Ask the WebSphere TraceService to hand down the logs from OpenJPA to the application. This is a setting in the WebSphere Administration Console
来源：https://stackoverflow.com/questions/8703105/openjpa-logging-with-slf4j-on-websphere