If you use JBoss and RestEasy, it's possible that you get some STDERR errors in your JBoss logs. If you get theses errors, it's because you don't put the
SL4J library in your classpath. To use Log4J and RestEasy, you must put slf4j-log4j12-X.X.X.jar and slf4j-api-X.X.X.jar in your classpath. You can find theses files by downloading the latest SLF4J distribution.
Example of logs before putting SL4J libs
12:18:00,109 INFO [TomcatDeployer] deploy, ctxPath=/XXX, warUrl=.../tmp/deploy/tmp250404096618978916XXX.ear-contents/XXX-war-exp.war/
12:18:00,423 ERROR [STDERR] 129 [main] INFO org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap - Adding listed @Provider class XXX.util.exceptionmapper.XXXExceptionMapper
12:18:00,439 ERROR [STDERR] 145 [main] INFO org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap - Adding listed @Provider class XXX.util.exceptionmapper.EJBExceptionMapper
12:18:00,451 ERROR [STDERR] 156 [main] INFO org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap - Adding listed @Provider class XXX.util.exceptionmapper.JSONExceptionMapper
12:18:00,457 ERROR [STDERR] 163 [main] INFO org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap - Adding listed @Provider class XXX.util.exceptionmapper.GeneralExceptionMapper
12:18:00,500 ERROR [STDERR] 206 [main] INFO org.jboss.resteasy.plugins.providers - Added built in provider DataSourceProvider
12:18:00,508 ERROR [STDERR] 214 [main] INFO org.jboss.resteasy.plugins.providers - Added built in provider DefaultTextPlain
12:18:00,515 ERROR [STDERR] 221 [main] INFO org.jboss.resteasy.plugins.providers - Added built in provider org.jboss.resteasy.plugins.providers.StringTextStar
...
12:18:00,851 ERROR [STDERR] 557 [main] INFO org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap - Adding jndi resource XXX/XXXBean/local
...
12:18:01,508 INFO [EARDeployer] Started J2EE application: file:/Users/yann/jboss-4.2.3.GA/server/default/deploy/XXX.ear
12:18:01,759 INFO [Http11Protocol] Starting Coyote HTTP/1.1 on http-127.0.0.1-8081
12:18:01,786 INFO [AjpProtocol] Starting Coyote AJP/1.3 on ajp-127.0.0.1-8009
Example of logs after putting SL4J libs
12:18:00,109 INFO [TomcatDeployer] deploy, ctxPath=/XXX, warUrl=.../tmp/deploy/tmp250404096618978916XXX.ear-contents/XXX-war-exp.war/
12:18:00,423 INFO [ResteasyBootstrap] Adding listed @Provider class XXX.util.exceptionmapper.XXXExceptionMapper
12:18:00,439 INFO [ResteasyBootstrap] Adding listed @Provider class XXX.util.exceptionmapper.EJBExceptionMapper
12:18:00,451 INFO [ResteasyBootstrap] Adding listed @Provider class XXX.util.exceptionmapper.JSONExceptionMapper
12:18:00,457 INFO [ResteasyBootstrap] Adding listed @Provider class XXX.util.exceptionmapper.GeneralExceptionMapper
12:18:00,500 INFO [providers] Added built in provider DataSourceProvider
12:18:00,508 INFO [providers] Added built in provider DefaultTextPlain
12:18:00,515 INFO [providers] Added built in provider org.jboss.resteasy.plugins.providers.StringTextStar
...
12:18:00,851 INFO [ResteasyBootstrap] Adding jndi resource XXX/XXXBean/local
...
12:18:01,508 INFO [EARDeployer] Started J2EE application: file:/Users/yann/jboss-4.2.3.GA/server/default/deploy/XXX.ear
12:18:01,759 INFO [Http11Protocol] Starting Coyote HTTP/1.1 on http-127.0.0.1-8081
12:18:01,786 INFO [AjpProtocol] Starting Coyote AJP/1.3 on ajp-127.0.0.1-8009