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/*
* $Id: DynaActionFormClass.java 54929 2004-10-16 16:38:42Z germuska $
*
* Copyright 2000-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.struts.action;
import java.io.Serializable;
import java.util.HashMap;
import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.DynaClass;
import org.apache.commons.beanutils.DynaProperty;
import org.apache.struts.config.FormBeanConfig;
import org.apache.struts.config.FormPropertyConfig;
import org.apache.struts.config.ModuleConfig;
import org.apache.struts.util.RequestUtils;
/**
* Implementation of DynaClass for
* DynaActionForm classes that allow developers to define
* ActionForms without having to individually code all of the classes.
* NOTE - This class is only used in the internal
* implementation of dynamic action form beans. Application developers
* never need to consult this documentation.
*
* @version $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $
* @since Struts 1.1
*/
public class DynaActionFormClass implements DynaClass, Serializable {
// ----------------------------------------------------------- Constructors
/**
* Construct a new DynaActionFormClass for the specified
* form bean configuration. This constructor is private;
* DynaActionFormClass instances will be created as needed via
* calls to the static createDynaActionFormClass() method.
*
* @param config The FormBeanConfig instance describing the properties
* of the bean to be created
*
* @exception IllegalArgumentException if the bean implementation class
* specified in the configuration is not DynaActionForm (or a subclass
* of DynaActionForm)
*/
public DynaActionFormClass(FormBeanConfig config) {
introspect(config);
}
// ----------------------------------------------------- Instance Variables
/**
* The DynaActionForm implementation Class
* which we will use to create new bean instances.
*/
protected transient Class beanClass = null;
/**
* The form bean configuration information for this class.
*/
protected FormBeanConfig config = null;
/**
* The "dynamic class name" for this DynaClass.
*/
protected String name = null;
/**
* The set of dynamic properties that are part of this DynaClass.
*/
protected DynaProperty properties[] = null;
/**
* The set of dynamic properties that are part of this
* DynaClass, keyed by the property name. Individual
* descriptor instances will be the same instances as those in the
* properties list.
*/
protected HashMap propertiesMap = new HashMap();
// ------------------------------------------------------ DynaClass Methods
/**
*
Return the name of this DynaClass (analogous to the
* getName() method of java.lang.ClassDynaClass implementation class to support
* different dynamic classes, with different sets of properties.
*/
public String getName() {
return (this.name);
}
/**
*
Return a property descriptor for the specified property, if it exists;
* otherwise, return null.
*
* @param name Name of the dynamic property for which a descriptor
* is requested
*
* @exception IllegalArgumentException if no property name is specified
*/
public DynaProperty getDynaProperty(String name) {
if (name == null) {
throw new IllegalArgumentException
("No property name specified");
}
return ((DynaProperty) propertiesMap.get(name));
}
/**
* Return an array of DynaPropertys for the properties
* currently defined in this DynaClass. If no properties are
* defined, a zero-length array will be returned.
*/
public DynaProperty[] getDynaProperties() {
return (properties);
// :FIXME: Should we really be implementing
// getBeanInfo instead, which returns property descriptors
// and a bunch of other stuff?
}
/**
* Instantiate and return a new {@link DynaActionForm} instance,
* associated with this DynaActionFormClass. The
* properties of the returned {@link DynaActionForm} will have been
* initialized to the default values specified in the form bean
* configuration information.
*
* @exception IllegalAccessException if the Class or the appropriate
* constructor is not accessible
* @exception InstantiationException if this Class represents an abstract
* class, an array class, a primitive type, or void; or if instantiation
* fails for some other reason
*/
public DynaBean newInstance()
throws IllegalAccessException, InstantiationException {
DynaActionForm dynaBean =
(DynaActionForm) getBeanClass().newInstance();
dynaBean.setDynaActionFormClass(this);
FormPropertyConfig props[] = config.findFormPropertyConfigs();
for (int i = 0; i < props.length; i++) {
dynaBean.set(props[i].getName(), props[i].initial());
}
return (dynaBean);
}
// --------------------------------------------------------- Public Methods
/**
* Render a String representation of this object.
*/
public String toString() {
StringBuffer sb = new StringBuffer("DynaActionFormBean[name=");
sb.append(name);
DynaProperty props[] = getDynaProperties();
if (props == null) {
props = new DynaProperty[0];
}
for (int i = 0; i < props.length; i++) {
sb.append(',');
sb.append(props[i].getName());
sb.append('/');
sb.append(props[i].getType());
}
sb.append("]");
return (sb.toString());
}
// --------------------------------------------------------- Static Methods
/**
* @deprecated No longer need to Clear our cache of DynaActionFormClass instances.
*/
public static void clear() {
}
/**
* Return the DynaActionFormClass instance for the specified form bean
* configuration instance.
*/
public static DynaActionFormClass
createDynaActionFormClass(FormBeanConfig config) {
return config.getDynaActionFormClass();
}
// ------------------------------------------------------ Protected Methods
/**
* Return the implementation class we are using to construct new
* instances, re-introspecting our {@link FormBeanConfig} if necessary
* (that is, after being deserialized, since beanClass is
* marked transient).
*/
protected Class getBeanClass() {
if (beanClass == null) {
introspect(config);
}
return (beanClass);
}
/**
* Introspect our form bean configuration to identify the supported
* properties.
*
* @param config The FormBeanConfig instance describing the properties
* of the bean to be created
*
* @exception IllegalArgumentException if the bean implementation class
* specified in the configuration is not DynaActionForm (or a subclass
* of DynaActionForm)
*/
protected void introspect(FormBeanConfig config) {
this.config = config;
// Validate the ActionFormBean implementation class
try {
beanClass = RequestUtils.applicationClass(config.getType());
} catch (Throwable t) {
throw new IllegalArgumentException
("Cannot instantiate ActionFormBean class '" +
config.getType() + "': " + t);
}
if (!DynaActionForm.class.isAssignableFrom(beanClass)) {
throw new IllegalArgumentException
("Class '" + config.getType() + "' is not a subclass of " +
"'org.apache.struts.action.DynaActionForm'");
}
// Set the name we will know ourselves by from the form bean name
this.name = config.getName();
// Look up the property descriptors for this bean class
FormPropertyConfig descriptors[] = config.findFormPropertyConfigs();
if (descriptors == null) {
descriptors = new FormPropertyConfig[0];
}
// Create corresponding dynamic property definitions
properties = new DynaProperty[descriptors.length];
for (int i = 0; i < descriptors.length; i++) {
properties[i] =
new DynaProperty(descriptors[i].getName(),
descriptors[i].getTypeClass());
propertiesMap.put(properties[i].getName(),
properties[i]);
}
}
}