See: Description
Interface | Description |
---|---|
InvocationContext |
Exposes contextual information about the intercepted invocation and operations that enable interceptor methods to
control the behavior of the invocation chain.
|
Class | Description |
---|---|
Interceptor.Priority |
Priorities that define the order in which interceptors are invoked.
|
Annotation Type | Description |
---|---|
AroundConstruct |
Designates an interceptor method that receives a callback when the target class constructor is invoked.
|
AroundInvoke |
Defines an interceptor method that interposes on business methods.
|
AroundTimeout |
Defines an interceptor method that interposes on timeout methods.
|
ExcludeClassInterceptors |
Used to exclude class-level interceptors for the lifecycle callback method, business method, timeout method, or
constructor to which it is applied.
|
ExcludeDefaultInterceptors |
Used to exclude default interceptors for a target class or for a lifecycle callback method, business method, timeout
method, or constructor of a target class.
|
Interceptor |
Specifies that a class is an interceptor.
|
InterceptorBinding |
Specifies that an annotation type is an interceptor binding type.
|
Interceptors |
Declares an ordered list of interceptors for a target class, or for a method or a constructor of a target class.
|
Contains annotations and interfaces for defining interceptor methods and interceptor classes, and for binding interceptor classes to target classes.
An interceptor method is a method of an interceptor class or of a target class that is invoked to interpose on the invocation of a method of the target class, a constructor of the target class, a lifecycle event of the target class, or a timeout method of the target class.
An interceptor method for a target class may be declared in the target class, in an interceptor class associated with the target class, or in a superclass of the target class or interceptor class.
An AroundConstruct
interceptor method may
be defined only in an interceptor class or superclass of an interceptor class.
The Jakarta Interceptors specification defines the interceptor method types listed below. Extension specifications may define additional interceptor method types.
AroundInvoke
interceptor methods,
which interpose on business methods of the target class. AroundTimeout
interceptor methods,
which interpose on the invocation of timeout methods, in response to timer events.PostConstruct
interceptor methods, which are invoked
after dependency injection has been completed on the target instance.PreDestroy
interceptor methods, which are invoked
before the target instance and all interceptor instances associated with it are
destroyed.AroundConstruct
interceptor methods, which interpose
on the invocation of the constructor of the target instance.PostConstruct
, PreDestroy
, and AroundConstruct
interceptor methods are
collectively referred to as lifecycle callback interceptor methods.
An interceptor method may be defined using annotations or,
optionally, by means of a deployment descriptor. Interceptor methods
may not be declared abstract
, static
, or
final
.
An interceptor class or target class may have multiple interceptor methods. However,
an interceptor class or target class may have no more than one interceptor method of a
given interceptor method type: AroundInvoke
,
AroundTimeout
, PostConstruct
,
PreDestroy
, AroundConstruct
.
An interceptor class is a class (distinct from the target class) whose methods are invoked in response to invocations and/or lifecycle events on the target class. Any number of interceptor classes may be associated with a target class.
An interceptor class must have a public constructor with no parameters.
Interceptor methods and interceptor classes may be defined for a class by means of metadata annotations or, optionally, by means of a deployment descriptor.
An interceptor class may be associated with the target class or a method of the target class in several ways:
Interceptor
annotation.Interceptors
annotation
to specify and associate one or more interceptor classes
with a target class or method or constructor of a target class.Any interceptor class may be defined to apply to a target class at the class level. In the case of around-invoke method interceptors, the interceptor applies to all business methods of the target class. In the case of timeout method interceptors, the interceptor applies to all timeout methods of the target class.
The ExcludeClassInterceptors
annotation or, if supported,
a deployment descriptor may be used to exclude the invocation of class level
interceptors defined by the Interceptors
annotation
for a method or constructor of a target class.
An around-invoke interceptor may be defined to apply only to a specific method of the target class. Likewise, an around-timeout interceptor may be defined to apply only to a specific timeout method of the target class. However, if an interceptor class that defines lifecycle callback interceptor methods is defined to apply to a target class at the method level, the lifecycle callback interceptor methods are not invoked.
Default interceptors are interceptors that apply to a set of target classes. If a deployment descriptor is supported, it may be used to define default interceptors and their relative ordering.
The ExcludeDefaultInterceptors
annotation may be used to
exclude the invocation of default interceptors for a target class or method or constructor of a target class.
The lifecycle of an interceptor instance is the same as that of the target class
instance with which it is associated. Except as noted below for AroundConstruct
lifecycle callback interceptors, when the target instance is created, a
corresponding interceptor instance is created for each associated interceptor class.
These interceptor instances are destroyed when the target instance fails to be created or
when it is removed.
An interceptor class shares the enterprise naming context of its associated target class. Annotations and/or XML deployment descriptor elements for dependency injection or for direct Naming and Directory Interface lookup refer to this shared naming context.
An interceptor instance may hold state. An interceptor instance may be the target of dependency injection. Dependency injection is performed when the interceptor instance is created, using the naming context of the associated target class.
With the exception of
of AroundConstruct
lifecycle callback interceptors,
no interceptor methods are invoked until after dependency injection has been
completed on both the interceptor instances and the target instance.
PostConstruct
interceptor methods, if any, are invoked after
dependency injection has taken place on both the interceptor instances and the target
instance.
PreDestroy
interceptor methods, if any, are
invoked before the target instance and all interceptor instances associated with it are
destroyed.
When a AroundConstruct
lifecycle callback interceptor
is used, the following rules apply:
AroundConstruct
lifecycle callback is invoked
after dependency injection has been completed on instances of all interceptor
classes associated with the target class. Injection of the target component into
interceptor instances that are invoked during the AroundConstruct
lifecycle callback is not supported.AroundConstruct
interceptor chain invokes the InvocationContext.proceed()
method.
If the InvocationContext.proceed()
method is not invoked by an
interceptor method, the target instance will not be created.AroundConstruct
interceptor method can access
the constructed instance using the InvocationContext.getTarget()
method after the InvocationContext.proceed()
completes.AroundConstruct
interceptor chain complete successfully.
PostConstruct
lifecycle callback chain for the
target instance, if any, will be invoked after dependency injection has been completed
on the target instance.AroundConstruct
lifecycle callback interceptor
method should exercise caution when invoking methods of the target instance since its
dependency injection may not have been completed.A lifecycle callback interceptor method is a non-final, non-static method. A
lifecycle callback interceptor method declared by the target class (or superclass) must
have no parameters. A lifecycle callback interceptor method declared by an interceptor
class must have a single parameter of type InvocationContext
.
@PostConstruct public void interceptPostConstruct(InvocationContext ctx) { ... }
A single lifecycle callback interceptor method may be used to interpose on multiple callback events.
@PostConstruct @PreDestroy public void interceptLifecycle(InvocationContext ctx) { ... }
A class may not declare more than one lifecycle callback interceptor method for a particular lifecycle event.
Lifecycle callback interceptor methods are invoked in an unspecified security context. Lifecycle callback interceptor methods are invoked in a transaction context determined by their target class and/or method. The transaction context may be also changed by transactional interceptors in the invocation chain.
Lifecycle callback interceptor methods may throw runtime exceptions but not checked
exceptions, except for AroundConstruct
methods, which may
throw may throw any exceptions that are allowed by the throws clause of the constructor
on which they are interposing.
AroundConstruct
,
AroundInvoke
,
AroundTimeout
,
Interceptors
,
InvocationContext
Copyright © 2021 JBoss by Red Hat. All rights reserved.