使用java.util.logging在Eclipse服务器端日志中进行GWT开发

Question

I have been developing my web application using eclipse (4.4) and GWT (2.6.0). I have an external jar that contains some functionality in pure java, as well as a GWT project that makes use of this jar in the server part (services/servlets). The GWT project was a pure eclipse project, which I converted at a later point in time to a maven project. The jar is built with maven and populated to the src/main/webapp/WEB-INF/lib/ directory where it works like a charm.

Short version: java.util.logging messages generated in the jar or the servlets are being ignored during development instead of being logged to the eclipse console.

Long version: The logging of messages in the jar and in the GWT servlets is implemented using java.util.logging. The problem is that during development I am only able to see some messages from the GWT-compilation process and library resolution messages that do not come from the java.util.logging facilities (eg have a DEBUG in them, which does not exist in java.util.logging), but none from my actual code or jar. When i add the following to the VM arguments in the run configuration of eclipse, I am able to see some info messages from my code, but none of the FINE, FINER, and FINEST levels, as well as none from the jar at all:

-Dorg.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog -D{classref}.LEVEL=DEBUG

I also tried putting the following logging.properties file in different places, such as src/main/resources, src/main/webapp/WEB-INF/lib/, src/main/webapp/WEB-INF/classes/, but none of the above worked so far.

handlers= java.util.logging.FileHandler, java.util.logging.ConsoleHandler

.level= ALL

java.util.logging.ConsoleHandler.level = ALL
java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter

I haven't deployed the app externally yet, so I don't know how it would behave in eg a Tomcat environment. The most frustrating thing is that I've been searching on the net for hours, but havent found anything remotely close to the goal of enabling logging and controlling the log levels in my current IDE config.

Client-side logging from the GWT itself works like a charm.

I would greatly appreciate any help on this topic! Thanks in advance :-)

EDIT: Based on the comments of Joakim Erdfelt and Thomas Broyer, I did an experiment permuting several different Jetty logging parameters which I passed to the VM through the -D argument in the eclipse run configuration (I found them here ).

Below are the results. The primary goal is to unlock all levels of logging.

1. No Jetty logging arguments -> working levels: SEVERE, WARNING, INFO. Complete VM args:

   -Xmx2048m -XstartOnFirstThread

2. java.util.logging.config.file (the file is in /src/main/resources/logging.properties, tried src/main/resources/logging.properties, /src/main/resources/logging.properties, logging.properties) -> no level working.

   -Xmx2048m -XstartOnFirstThread -Djava.util.logging.config.file=src/main/resources/logging.properties

3. -D{classref}.LEVEL=ALL or -D{classref}.LEVEL=FINEST -> working levels: SEVERE, WARNING, INFO.

   -Xmx2048m -XstartOnFirstThread -D{classref}.LEVEL=ALL

4. This also changes nothing. Visible levels are: SEVERE, WARNING, INFO. Complete VM args:

   -Xmx2048m -XstartOnFirstThread -D{classref}.LEVEL=ALL -Dorg.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StrErrLog

So guys, the question is still open. Obviously the logging works, however I am unable to set the levels correctly. I must be missing something obvious...

Answer 1

Apparently, it is impossible to tell the embedded Jetty of GWT to use the java.util.logging framework in the config I use. I find the decision of the GWT team not to enable this a bit peculiar to say the least, because (an emulation of) the java.util.logging framework is used for the client-side logging. So it would be natural to not mix two different ways of logging in an application and use java.util.logging also for the servlets. It is a pity. Thanks Joakim for pointing this out.