Java Reference
In-Depth Information
Multiple interceptors may also be defined in the deployment descriptor. The order of the
interceptors in the deployment descriptor is the order in which the interceptors will be in-
voked.
...
<interceptor-binding>
<target-name>myapp.OrderBean</target-name>
<interceptor-class>myapp.PrimaryInterceptor.class</interceptor-
class>
<interceptor-
class>myapp.SecondaryInterceptor.class</interceptor-class>
<interceptor-class>myapp.LastInterceptor.class</interceptor-
class>
<method-name>updateInfo</method-name>
</interceptor-binding>
...
To explicitly pass control to the next interceptor in the chain, call the
InvocationCon-
text.proceed
method.
Data can be shared across interceptors:
• The same
InvocationContext
instance is passed as an input parameter to
each interceptor method in the interceptor chain for a particular target method.
The
InvocationContext
instance's
contextData
property is used to pass
data across interceptor methods. The
contextData
property is a
java.util.Map<String, Object>
object. Data stored in
contextData
is accessible to interceptor methods further down the interceptor chain.
• The data stored in
contextData
is not sharable across separate target class
method invocations. That is, a different
InvocationContext
object is created
for each invocation of the method in the target class.
Accessing Target Method Parameters From an Interceptor Class
The
InvocationContext
instance passed to each around-invoke method may be used
to access and modify the parameters of the target method. The
parameters
property
of
InvocationContext
is an array of
Object
instances that corresponds to the
parameter order of the target method. For example, for the following target method, the
parameters
property, in the
InvocationContext
instance passed to the around-
invoke interceptor method in
PrimaryInterceptor
, is an
Object
array containing
two
String
objects (
firstName
and
lastName
) and a
Date
object (
date
):
