Tapping into Stripes - Stripes...and Java Web Development is Fun Again - page 285

That's a neat way to intercept execution for a specific action bean. We
can also write an interceptor that runs for the whole application.
Implementing Interceptors
For a global interceptor, implement the Interceptor interface, and either
place the class in an extension package or configure it in the web.xml
file.
The Interceptor interface is simple:
public interface Interceptor {
Resolution intercept(ExecutionContext context) throws Exception;
}
To indicate the life-cycle stages that we want to intercept, we annotate
our class with @Intercepts . For example:
@Intercepts(LifecycleStage.ActionBeanResolution)
public class MyInterceptor implements Interceptor {
public Resolution intercept(ExecutionContext context) {
// ...
}
}
Instead of using @Before or @After to indicate whether our interceptor
code should run before or after the life-cycle stages, we call proceed ( )
on the ExecutionContext object that's passed to the intercept ( ) method.
That executes the life-cycle stage. So, the code we put around the call
to proceed ( ) is executed before or after, accordingly:
@Intercepts(LifecycleStage.ActionBeanResolution)
public class MyInterceptor implements Interceptor {
public Resolution intercept(ExecutionContext context)
// proceed() can throw an Exception so we have to declare it
throws Exception
{
// do something before
Resolution resolution = context.proceed();
// do something after
return resolution;
}
}
Notice how proceed ( ) returns a resolution; returning that value from
intercept ( ) effectively lets the life-cycle sequence continue normally. If,