public class ActionForm extends Object implements Serializable
An ActionForm is a JavaBean optionally associated with
one or more ActionMappings. Such a bean will have had its
properties initialized from the corresponding request parameters before the
corresponding Action.execute method is called.
When the properties of this bean have been populated, but before the
execute method of the Action is called, this
bean's validate method will be called, which gives the bean a
chance to verify that the properties submitted by the user are correct and
valid. If this method finds problems, it returns an error messages object
that encapsulates those problems, and the controller servlet will return
control to the corresponding input form. Otherwise, the
validate method returns null, indicating that
everything is acceptable and the corresponding Action.execute
method should be called.
This class must be subclassed in order to be instantiated. Subclasses should provide property getter and setter methods for all of the bean properties they wish to expose, plus override any of the public or protected methods for which they wish to provide modified functionality.
Because ActionForms are JavaBeans, subclasses should also implement
Serializable, as required by the JavaBean specification. Some
containers require that an object meet all JavaBean requirements in order
to use the introspection API upon which ActionForms rely.
org.apache.struts.action.ActionForm,
直列化された形式| コンストラクタと説明 |
|---|
ActionForm() |
| 修飾子とタイプ | メソッドと説明 |
|---|---|
void |
reset()
リセットメソッド
|
void |
reset(ActionMapping mapping,
javax.servlet.http.HttpServletRequest request)
Can be used to reset bean properties to their default state, as
needed.
|
void |
reset(ActionMapping mapping,
javax.servlet.ServletRequest request)
Can be used to reset all bean properties to their default state.
|
ActionErrors |
validate(ActionMapping mapping,
javax.servlet.http.HttpServletRequest request)
Can be used to validate the properties that have been set for this
HTTP request, and return an
ActionErrors object that
encapsulates any validation errors that have been found. |
ActionErrors |
validate(ActionMapping mapping,
javax.servlet.ServletRequest request)
Can be used to validate the properties that have been set for this
non-HTTP request, and return an
ActionErrors object that
encapsulates any validation errors that have been found. |
public void reset(ActionMapping mapping, javax.servlet.ServletRequest request)
Can be used to reset all bean properties to their default state. This method is called before the properties are repopulated by the controller.
The default implementation attempts to forward to the HTTP version of this method.
mapping - The mapping used to select this instancerequest - The servlet request we are processingpublic void reset(ActionMapping mapping, javax.servlet.http.HttpServletRequest request)
Can be used to reset bean properties to their default state, as needed. This method is called before the properties are repopulated by the controller.
The default implementation does nothing. In practice, the only properties that need to be reset are those which represent checkboxes on a session-scoped form. Otherwise, properties can be given initial values where the field is declared.
If the form is stored in session-scope so that values can be collected over multiple requests (a "wizard"), you must be very careful of which properties, if any, are reset. As mentioned, session-scope checkboxes must be reset to false for any page where this property is set. This is because the client does not submit a checkbox value when it is clear (false). If a session-scoped checkbox is not proactively reset, it can never be set to false.
This method is not the appropriate place to initialize form value for an "update" type page (this should be done in a setup Action). You mainly need to worry about setting checkbox values to false; most of the time you can leave this method unimplemented.
mapping - The mapping used to select this instancerequest - The servlet request we are processingpublic ActionErrors validate(ActionMapping mapping, javax.servlet.ServletRequest request)
Can be used to validate the properties that have been set for this
non-HTTP request, and return an ActionErrors object that
encapsulates any validation errors that have been found. If no errors
are found, return null or an ActionErrors
object with no recorded error messages.
The default implementation attempts to forward to the HTTP version of this method.
mapping - The mapping used to select this instancerequest - The servlet request we are processingnull if validation succeeded.public ActionErrors validate(ActionMapping mapping, javax.servlet.http.HttpServletRequest request)
Can be used to validate the properties that have been set for this
HTTP request, and return an ActionErrors object that
encapsulates any validation errors that have been found. If no errors
are found, return null or an ActionErrors
object with no recorded error messages.
The default implementation performs no validation and returns
null. Subclasses must override this method to provide any
validation they wish to perform.
mapping - The mapping used to select this instancerequest - The servlet request we are processingnull if validation succeeded.DynaActionFormpublic void reset()