7.5. XML (or MetaData) Annotations Support
AOP support is a prime feature in JBoss Microcontainer. You can use AOP aspects and plain beans in any combination. Example 7.10, “Intercepting a Method based on Annotation” attempts to intercept a method invocation based on an annotation. The annotation can come from anywhere. It might be a true class annotation or an annotation added through the xml configuration.
Example 7.10. Intercepting a Method based on Annotation
<interceptor xmlns="urn:jboss:aop-beans:1.0" name="StopWatchInterceptor" class="org.jboss.demos.ioc.annotations.StopWatchInterceptor"/> <bind xmlns="urn:jboss:aop-beans:1.0" pointcut="execution(* @org.jboss.demos.ioc.annotations.StopWatchLog->*(..)) OR execution(* *->@org.jboss.demos.ioc.annotations.StopWatchLog(..))"> <interceptor-ref name="StopWatchInterceptor"/> </bind> </interceptor>
public class StopWatchInterceptor implements Interceptor {
...
public Object invoke(Invocation invocation) throws Throwable
{
Object target = invocation.getTargetObject();
long time = System.currentTimeMillis();
log.info("Invocation [" + target + "] start: " + time);
try
{
return invocation.invokeNext();
}
finally
{
log.info("Invocation [" + target + "] time: " + (System.currentTimeMillis() - time));
}
}
}
Example 7.11, “A true class annotated executor” and Example 7.12, “Simple executor with XML annotation” show some different ways to implement executors.
Example 7.11. A true class annotated executor
<bean name="AnnotatedExecutor" class="org.jboss.demos.ioc.annotations.AnnotatedExecutor">
public class AnnotatedExecutor implements Executor {
...
@StopWatchLog // <-- Pointcut match!
public void execute() throws Exception {
delegate.execute();
}
}
Example 7.12. Simple executor with XML annotation
<bean name="SimpleExecutor" class="org.jboss.demos.ioc.annotations.SimpleExecutor"> <annotation>@org.jboss.demos.ioc.annotations.StopWatchLog</annotation> // <-- Pointcut match! </bean>
public class SimpleExecutor implements Executor {
private static Random random = new Random();
public void execute() throws Exception
{
Thread.sleep(Math.abs(random.nextLong() % 101));
}
}
After adding executor invoker beans, you can see the executors in action during employment, by looking for log output such as Example 7.13, “Executor Logging Output”.
Example 7.13. Executor Logging Output
JBoss-MC-Demo INFO [15-12-2008 13:57:39] StopWatch - Invocation [org.jboss.demos.ioc.annotations.AnnotatedExecutor@4d28c7] start: 1229345859234 JBoss-MC-Demo INFO [15-12-2008 13:57:39] StopWatch - Invocation [org.jboss.demos.ioc.annotations.AnnotatedExecutor@4d28c7] time: 31 JBoss-MC-Demo INFO [15-12-2008 13:57:39] StopWatch - Invocation [org.jboss.demos.ioc.annotations.SimpleExecutor@1b044df] start: 1229345859265 JBoss-MC-Demo INFO [15-12-2008 13:57:39] StopWatch - Invocation [org.jboss.demos.ioc.annotations.SimpleExecutor@1b044df] time: 47
