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` for DynaBeans that wrap standard JavaBean instances.

  It is suggested that this class should not usually need to be used directly to create new `WrapDynaBean` instances. It's usually better to call the `WrapDynaBean` constructor directly. 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

    All Methods Static Methods Instance Methods Concrete Methods
    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.ClassDynaClass` 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.ClassDynaClass` 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.

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