Using CDI with EJB 3 - EJB 3 in Action - page 494

Documentation on the InvocationContext methods is shown in table 12.3 . This class
provides a wealth of information about the method you're intercepting along with each
method's parameters and other context information.

Table 12.3. Methods on InvocationContext

Method Description

Object getTarget(); Returns the object instance you're performing interception on

Object getTimer(); Returns the timer object associated with the timeout

Method getMethod(); Returns the method on which you're performing interception

Object[] getParameters(); Returns the parameters that are to be passed to the method

A setter enabling you to change the parameters used to invoke the target meth-
od

void setParameters(Object[] os);

Map<String, Object> getContex-
tData();

Returns context data associated with this invocation—information from the an-
notation

Object proceed() throws Exception; Proceeds with invoking the method

Once you've defined the interceptor, the next step is to actually use it. You can annotate
either the class or individual methods within a class. To use it on the LandingControl-
ler , you'd add it as follows:

@Named
@ApplicationScoped
@PerformanceMonitor
public class LandingController {
...

}

Adding the annotation to the LandingController doesn't enable it by default. Inter-
ceptors must be enabled in the beans.xml file. The following snippet enables this intercept-
or:

<interceptors>
<class>com.actionbazaar.util.PerformanceInterceptor</class>
</interceptors>

With the interceptor enabled, each method invocation on the LandingController is
tracked. You can annotate other classes as needed. If you're using multiple interceptors,
the order in which they appear within the beans.xml file will determine the order in
which they're executed. Additional interceptors are configured by adding additional
<class></class> elements.