org.apache.commons.beanutils

Class WrapDynaClass

java.lang.Object

org.apache.commons.beanutils.WrapDynaClass

All Implemented Interfaces:

DynaClass

public class WrapDynaClass
extends Object
implements DynaClass

Implementation of DynaClass that wrap standard JavaBean instances.

This class should not usually need to be used directly to create new WrapDynaBean instances - it's usually better to call the WrapDynaBean constructor. For example:

   Object javaBean = ...;
   DynaBean wrapper = new WrapDynaBean(javaBean);
 

Version:

$Id$

Field Summary

Fields

Modifier and Type	Field and Description
protected Class<?>	beanClass Deprecated. No longer initialized, use getBeanClass() method instead
protected PropertyDescriptor[]	descriptors The set of PropertyDescriptors for this bean class.
protected HashMap<String,PropertyDescriptor>	descriptorsMap The set of PropertyDescriptors for this bean class, keyed by the property name.
protected static HashMap<Object,Object>	dynaClasses Deprecated. The dynaClasses Map will be removed in a subsequent release
protected DynaProperty[]	properties The set of dynamic properties that are part of this DynaClass.
protected HashMap<String,DynaProperty>	propertiesMap The set of dynamic properties that are part of this DynaClass, keyed by the property name.

Method Summary

Modifier and Type	Method and Description
static void	clear() Clear our cache of WrapDynaClass instances.
static WrapDynaClass	createDynaClass(Class<?> beanClass) Create (if necessary) and return a new WrapDynaClass instance for the specified bean class.
static WrapDynaClass	createDynaClass(Class<?> beanClass, PropertyUtilsBean pu) Create (if necessary) and return a new WrapDynaClass instance for the specified bean class using the given PropertyUtilsBean instance for introspection.
protected Class<?>	getBeanClass() Return the class of the underlying wrapped bean.
DynaProperty[]	getDynaProperties() Return an array of ProperyDescriptors for the properties currently defined in this DynaClass.
DynaProperty	getDynaProperty(String name) Return a property descriptor for the specified property, if it exists; otherwise, return null.
String	getName() Return the name of this DynaClass (analogous to the getName() method of java.lang.Class, which allows the same DynaClass implementation class to support different dynamic classes, with different sets of properties.
PropertyDescriptor	getPropertyDescriptor(String name) Return the PropertyDescriptor for the specified property name, if any; otherwise return null.
protected PropertyUtilsBean	getPropertyUtilsBean() Returns the PropertyUtilsBean instance associated with this class.
protected void	introspect() Introspect our bean class to identify the supported properties.
DynaBean	newInstance() Instantiates a new standard JavaBean instance associated with this DynaClass and return it wrapped in a new WrapDynaBean instance.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

beanClass

@Deprecated
protected Class<?> beanClass

Deprecated. No longer initialized, use getBeanClass() method instead

The JavaBean Class which is represented by this WrapDynaClass.

descriptors

protected PropertyDescriptor[] descriptors

The set of PropertyDescriptors for this bean class.

descriptorsMap

protected HashMap<String,PropertyDescriptor> descriptorsMap

The set of PropertyDescriptors for this bean class, keyed by the property name. Individual descriptor instances will be the same instances as those in the descriptors list.

properties

protected DynaProperty[] properties

The set of dynamic properties that are part of this DynaClass.

propertiesMap

protected HashMap<String,DynaProperty> propertiesMap

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.

dynaClasses

@Deprecated
protected static HashMap<Object,Object> dynaClasses

Deprecated. The dynaClasses Map will be removed in a subsequent release

The set of WrapDynaClass instances that have ever been created, keyed by the underlying bean Class. The keys to this map are Class objects, and the values are corresponding WrapDynaClass objects.

This static variable is safe even when this code is deployed via a shared classloader because it is keyed via a Class object. The same class loaded via two different classloaders will result in different entries in this map.

Note, however, that this HashMap can result in a memory leak. When this class is in a shared classloader it will retain references to classes loaded via a webapp classloader even after the webapp has been undeployed. That will prevent the entire classloader and all the classes it refers to and all their static members from being freed. !!!!!!!!!!!! PLEASE NOTE !!!!!!!!!!!! ************* THE FOLLOWING IS A NASTY HACK TO SO THAT BEANUTILS REMAINS BINARY COMPATIBLE WITH PREVIOUS RELEASES. There are two issues here: 1) Memory Issues: The static HashMap caused memory problems (See BEANUTILS-59) to resolve this it has been moved into a ContextClassLoaderLocal instance (named CLASSLOADER_CACHE above) which holds one copy per ClassLoader in a WeakHashMap. 2) Binary Compatibility: As the "dynaClasses" static HashMap is "protected" removing it breaks BeanUtils binary compatibility with previous versions. To resolve this all the methods have been overriden to delegate to the Map for the ClassLoader in the ContextClassLoaderLocal.

Method Detail

getBeanClass

protected Class<?> getBeanClass()

Return the class of the underlying wrapped bean.

Returns:

the class of the underlying wrapped bean

Since:

1.8.0

getName

public String getName()

Return the name of this DynaClass (analogous to the getName() method of java.lang.Class, which allows the same DynaClass implementation class to support different dynamic classes, with different sets of properties.

Specified by:

getName in interface DynaClass

Returns:

the name of the DynaClass

getDynaProperty

public DynaProperty getDynaProperty(String name)

Return a property descriptor for the specified property, if it exists; otherwise, return null.

Specified by:

getDynaProperty in interface DynaClass

Parameters:

name - Name of the dynamic property for which a descriptor is requested

Returns:

The descriptor for the specified property

Throws:

IllegalArgumentException - if no property name is specified

getDynaProperties

public DynaProperty[] getDynaProperties()

Return an array of ProperyDescriptors for the properties currently defined in this DynaClass. If no properties are defined, a zero-length array will be returned.

FIXME - Should we really be implementing getBeanInfo() instead, which returns property descriptors and a bunch of other stuff?

Specified by:

getDynaProperties in interface DynaClass

Returns:

the set of properties for this DynaClass

newInstance

public DynaBean newInstance()
                     throws IllegalAccessException,
                            InstantiationException

Instantiates a new standard JavaBean instance associated with this DynaClass and return it wrapped in a new WrapDynaBean instance. NOTE the JavaBean should have a no argument constructor.

NOTE - Most common use cases should not need to use this method. It is usually better to create new WrapDynaBean instances by calling its constructor. For example:

   Object javaBean = ...;
   DynaBean wrapper = new WrapDynaBean(javaBean);
 

(This method is needed for some kinds of DynaBean framework.)

Specified by:

newInstance in interface DynaClass

Returns:

A new DynaBean instance

Throws:

IllegalAccessException - if the Class or the appropriate constructor is not accessible

InstantiationException - if this Class represents an abstract class, an array class, a primitive type, or void; or if instantiation fails for some other reason

getPropertyDescriptor

public PropertyDescriptor getPropertyDescriptor(String name)

Return the PropertyDescriptor for the specified property name, if any; otherwise return null.

Parameters:

name - Name of the property to be retrieved

Returns:

The descriptor for the specified property

clear

public static void clear()

Clear our cache of WrapDynaClass instances.

createDynaClass

public static WrapDynaClass createDynaClass(Class<?> beanClass)

Create (if necessary) and return a new WrapDynaClass instance for the specified bean class.

Parameters:

beanClass - Bean class for which a WrapDynaClass is requested

Returns:

A new Wrap DynaClass

createDynaClass

public static WrapDynaClass createDynaClass(Class<?> beanClass,
                                            PropertyUtilsBean pu)

Create (if necessary) and return a new WrapDynaClass instance for the specified bean class using the given PropertyUtilsBean instance for introspection. Using this method a specially configured PropertyUtilsBean instance can be hooked into the introspection mechanism of the managed bean. The argument is optional; if no PropertyUtilsBean object is provided, the default instance is used.

Parameters:

beanClass - Bean class for which a WrapDynaClass is requested

pu - the optional PropertyUtilsBean to be used for introspection

Returns:

A new Wrap DynaClass

Since:

1.9

getPropertyUtilsBean

protected PropertyUtilsBean getPropertyUtilsBean()

Returns the PropertyUtilsBean instance associated with this class. This bean is used for introspection.

Returns:

the associated PropertyUtilsBean instance

Since:

1.9

introspect

protected void introspect()

Introspect our bean class to identify the supported properties.