com.opensymphony.xwork2.interceptor
Class PrepareInterceptor
java.lang.Object
com.opensymphony.xwork2.interceptor.AbstractInterceptor
com.opensymphony.xwork2.interceptor.PrepareInterceptor
- All Implemented Interfaces:
- Interceptor, Serializable
public class PrepareInterceptor
- extends AbstractInterceptor
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.
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>
Date: Nov 5, 2003 2:33:11 AM
- Author:
- Jason Carreira, Philip Luppens, tm_jee
- See Also:
Preparable
,
Serialized Form
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
serialVersionUID
private static final long serialVersionUID
- See Also:
- Constant Field Values
_log
private static final Log _log
PREPARE_PREFIX
private static final String PREPARE_PREFIX
- See Also:
- Constant Field Values
ALT_PREPARE_PREFIX
private static final String ALT_PREPARE_PREFIX
- See Also:
- Constant Field Values
alwaysInvokePrepare
private boolean alwaysInvokePrepare
PrepareInterceptor
public PrepareInterceptor()
setAlwaysInvokePrepare
public void setAlwaysInvokePrepare(String alwaysInvokePrepare)
intercept
public String intercept(ActionInvocation invocation)
throws Exception
- Description copied from class:
AbstractInterceptor
- Override to handle interception
- Specified by:
intercept
in interface Interceptor
- Specified by:
intercept
in class AbstractInterceptor
- Returns:
- the return code, either returned from
ActionInvocation.invoke()
, or from the interceptor itself.
- Throws:
Exception
- any system-level error, as defined in Action.execute()
.
Copyright © 2000-2007 Apache Software Foundation. All Rights Reserved.