com.opensymphony.xwork2.interceptor
Class PrepareInterceptor
java.lang.Object
com.opensymphony.xwork2.interceptor.AbstractInterceptor
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor
com.opensymphony.xwork2.interceptor.PrepareInterceptor
- All Implemented Interfaces:
- Interceptor, java.io.Serializable
public class PrepareInterceptor
- extends MethodFilterInterceptor
This interceptor calls prepare()
on actions which implement
Preparable
. This interceptor is very useful for any situation where
you need to ensure some logic runs before the actual execute method runs.
A typical use of this is to run some logic to load an object from the
database so that when parameters are set they can be set on this object. For
example, suppose you have a User object with two properties: id and
name. Provided that the params interceptor is called twice (once
before and once after this interceptor), you can load the User object using
the id property, and then when the second params interceptor is called the
parameter user.name will be set, as desired, on the actual object
loaded from the database. See the example for more info.
Note: Since XWork 2.0.2, this interceptor extends MethodFilterInterceptor
, therefore being
able to deal with excludeMethods / includeMethods parameters. See [Workflow Interceptor]
(class DefaultWorkflowInterceptor
) for documentation and examples on how to use this feature.
Update: Added logic to execute a prepare{MethodName} and conditionally
the a general prepare() Method, depending on the 'alwaysInvokePrepare' parameter/property
which is by default true. This allows us to run some logic based on the method
name we specify in the ActionProxy
. For example, you can specify a
prepareInput() method that will be run before the invocation of the input method.
Interceptor parameters:
- alwaysInvokePrepare - Default to true. If true, prepare will always be invoked,
otherwise it will not.
Extending the interceptor:
There are no known extension points to this interceptor.
Example code:
<!-- Calls the params interceptor twice, allowing you to
pre-load data for the second time parameters are set -->
<action name="someAction" class="com.examples.SomeAction">
<interceptor-ref name="params"/>
<interceptor-ref name="prepare"/>
<interceptor-ref name="basicStack"/>
<result name="success">good_result.ftl</result>
</action>
- Author:
- Jason Carreira, Philip Luppens, tm_jee
- See Also:
Preparable
,
Serialized Form
Method Summary |
java.lang.String |
doIntercept(ActionInvocation invocation)
Subclasses must override to implement the interceptor logic. |
void |
setAlwaysInvokePrepare(java.lang.String alwaysInvokePrepare)
Sets if the preapare method should always be executed. |
void |
setFirstCallPrepareDo(java.lang.String firstCallPrepareDo)
Sets if the prepareDoXXX method should be called first
Default is false for backward compatibility |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
PrepareInterceptor
public PrepareInterceptor()
setAlwaysInvokePrepare
public void setAlwaysInvokePrepare(java.lang.String alwaysInvokePrepare)
- Sets if the
preapare
method should always be executed.
Default is true.
- Parameters:
alwaysInvokePrepare
- if prepare
should always be executed or not.
setFirstCallPrepareDo
public void setFirstCallPrepareDo(java.lang.String firstCallPrepareDo)
- Sets if the
prepareDoXXX
method should be called first
Default is false for backward compatibility
- Parameters:
firstCallPrepareDo
- if prepareDoXXX
should be called first
doIntercept
public java.lang.String doIntercept(ActionInvocation invocation)
throws java.lang.Exception
- Description copied from class:
MethodFilterInterceptor
- Subclasses must override to implement the interceptor logic.
- Specified by:
doIntercept
in class MethodFilterInterceptor
- Parameters:
invocation
- the action invocation
- Returns:
- the result of invocation
- Throws:
java.lang.Exception
Copyright © 2000-2012 Apache Software Foundation. All Rights Reserved.