Apache Struts API Documentation: Class DynaActionForm

org.apache.struts.action Class DynaActionForm

java.lang.Object
  |
  +--org.apache.struts.action.ActionForm
        |
        +--org.apache.struts.action.DynaActionForm

All Implemented Interfaces:

org.apache.commons.beanutils.DynaBean, java.io.Serializable

Direct Known Subclasses:

DynaValidatorForm

public class DynaActionForm

extends ActionForm

implements org.apache.commons.beanutils.DynaBean

Specialized subclass of ActionForm that allows the creation of form beans with dynamic sets of properties, without requiring the developer to create a Java class for each type of form bean.

USAGE NOTE - Since Struts 1.1, the reset method no longer initializes property values to those specified in <form-property> elements in the Struts module configuration file. If you wish to utilize that behavior, the simplest solution is to subclass DynaActionForm and call the initialize method inside it.

Since:

Struts 1.1

Version:

$Rev: 168012 $ $Date: 2005-05-03 23:39:10 +0100 (Tue, 03 May 2005) $

See Also:

Serialized Form

dynaClass

protected DynaActionFormClass dynaClass

The DynaActionFormClass with which we are associated.

dynaValues

protected java.util.HashMap dynaValues

The set of property values for this DynaActionForm, keyed by property name.

DynaActionForm

public DynaActionForm()

initialize

public void initialize(ActionMapping mapping)

Initialize all bean properties to their initial values, as specified in the FormPropertyConfig elements associated with the definition of this DynaActionForm.

Parameters:

mapping - The mapping used to select this instance

initialize

public void initialize(FormBeanConfig config)

reset

public void reset(ActionMapping mapping,
                  javax.servlet.ServletRequest request)

Reset bean properties to their default state, as needed. 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.

Overrides:

reset in class ActionForm

Parameters:

mapping - The mapping used to select this instance

request - The servlet request we are processing

reset

public void reset(ActionMapping mapping,
                  javax.servlet.http.HttpServletRequest request)

Reset bean properties to their default state, as needed. This method is called before the properties are repopulated by the controller.

The default implementation (since Struts 1.1) does nothing. Subclasses may override this method to reset bean properties to default values, or the initialize method may be used to initialize property values to those provided in the form property configuration information (which was the behavior of this method in some release candidates).

Overrides:

reset in class ActionForm

Parameters:

mapping - The mapping used to select this instance

request - The servlet request we are processing

contains

public boolean contains(java.lang.String name,
                        java.lang.String key)

Indicates if the specified mapped property contain a value for the specified key value.

Specified by:

contains in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property to check

key - Name of the key to check

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

get

public java.lang.Object get(java.lang.String name)

Return the value of a simple property with the specified name.

Specified by:

get in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property whose value is to be retrieved

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

NullPointerException - if the type specified for the property is invalid

get

public java.lang.Object get(java.lang.String name,
                            int index)

Return the value of an indexed property with the specified name.

Specified by:

get in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property whose value is to be retrieved

index - Index of the value to be retrieved

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

java.lang.IllegalArgumentException - if the specified property exists, but is not indexed

java.lang.IndexOutOfBoundsException - if the specified index is outside the range of the underlying property

NullPointerException - if no array or List has been initialized for this property

get

public java.lang.Object get(java.lang.String name,
                            java.lang.String key)

Return the value of a mapped property with the specified name, or null if there is no value for the specified key.

Specified by:

get in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property whose value is to be retrieved

key - Key of the value to be retrieved

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

java.lang.IllegalArgumentException - if the specified property exists, but is not mapped

getString

public java.lang.String getString(java.lang.String name)

Return the value of a String property with the specified name. This is equivalent to calling (String) dynaForm.get(name).

Parameters:

name - Name of the property whose value is to be retrieved

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

NullPointerException - if the type specified for the property is invalid

ClassCastException - if the property is not a String.

Since:

Struts 1.2

getStrings

public java.lang.String[] getStrings(java.lang.String name)

Return the value of a String[] property with the specified name. This is equivalent to calling (String[]) dynaForm.get(name).

Parameters:

name - Name of the property whose value is to be retrieved

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

NullPointerException - if the type specified for the property is invalid

ClassCastException - if the property is not a String[].

Since:

Struts 1.2

getDynaClass

public org.apache.commons.beanutils.DynaClass getDynaClass()

Return the DynaClass instance that describes the set of properties available for this DynaBean.

Specified by:

getDynaClass in interface org.apache.commons.beanutils.DynaBean

getMap

public java.util.Map getMap()

Returns the Map containing the property values. This is done mostly to facilitate accessing the DynaActionForm through JavaBeans accessors, in order to use the JavaServer Pages Standard Tag Library (JSTL).

For instance, the normal JSTL EL syntax for accessing an ActionForm would be something like this:

  ${formbean.prop}

The JSTL EL syntax for accessing a DynaActionForm looks something like this (because of the presence of this getMap() method):

  ${dynabean.map.prop}

remove

public void remove(java.lang.String name,
                   java.lang.String key)

Remove any existing value for the specified key on the specified mapped property.

Specified by:

remove in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property for which a value is to be removed

key - Key of the value to be removed

Throws:

java.lang.IllegalArgumentException - if there is no property of the specified name

set

public void set(java.lang.String name,
                java.lang.Object value)

Set the value of a simple property with the specified name.

Specified by:

set in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property whose value is to be set

value - Value to which this property is to be set

Throws:

org.apache.commons.beanutils.ConversionException - if the specified value cannot be converted to the type required for this property

java.lang.IllegalArgumentException - if there is no property of the specified name

NullPointerException - if the type specified for the property is invalid

NullPointerException - if an attempt is made to set a primitive property to null

set

public void set(java.lang.String name,
                int index,
                java.lang.Object value)

Set the value of an indexed property with the specified name.

Specified by:

set in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property whose value is to be set

index - Index of the property to be set

value - Value to which this property is to be set

Throws:

org.apache.commons.beanutils.ConversionException - if the specified value cannot be converted to the type required for this property

java.lang.IllegalArgumentException - if there is no property of the specified name

java.lang.IllegalArgumentException - if the specified property exists, but is not indexed

java.lang.IndexOutOfBoundsException - if the specified index is outside the range of the underlying property

set

public void set(java.lang.String name,
                java.lang.String key,
                java.lang.Object value)

Set the value of a mapped property with the specified name.

Specified by:

set in interface org.apache.commons.beanutils.DynaBean

Parameters:

name - Name of the property whose value is to be set

key - Key of the property to be set

value - Value to which this property is to be set

Throws:

org.apache.commons.beanutils.ConversionException - if the specified value cannot be converted to the type required for this property

java.lang.IllegalArgumentException - if there is no property of the specified name

java.lang.IllegalArgumentException - if the specified property exists, but is not mapped

toString

public java.lang.String toString()

Render a String representation of this object.

Overrides:

toString in class java.lang.Object

setDynaActionFormClass

void setDynaActionFormClass(DynaActionFormClass dynaClass)

Set the DynaActionFormClass instance with which we are associated.

Parameters:

dynaClass - The DynaActionFormClass instance for this bean

getDynaProperty

protected org.apache.commons.beanutils.DynaProperty getDynaProperty(java.lang.String name)

Return the property descriptor for the specified property name.

Parameters:

name - Name of the property for which to retrieve the descriptor

Throws:

java.lang.IllegalArgumentException - if this is not a valid property name for our DynaClass

isDynaAssignable

protected boolean isDynaAssignable(java.lang.Class dest,
                                   java.lang.Class source)

Indicates if an object of the source class is assignable to the destination class.

Parameters:

dest - Destination class

source - Source class