org.apache.commons.beanutils

Class BaseDynaBeanMapDecorator<K>

java.lang.Object

org.apache.commons.beanutils.BaseDynaBeanMapDecorator<K>

Type Parameters:

K - the type of the keys in the decorated map

All Implemented Interfaces:

Map<K,Object>

Direct Known Subclasses:

DynaBeanMapDecorator, DynaBeanPropertyMapDecorator

public abstract class BaseDynaBeanMapDecorator<K>
extends Object
implements Map<K,Object>

A base class for decorators providing Map behavior on DynaBeans.

The motivation for this implementation is to provide access to DynaBean properties in technologies that are unaware of BeanUtils and DynaBeans - such as the expression languages of JSTL and JSF.

This rather technical base class implements the methods of the Map interface on top of a DynaBean. It was introduced to handle generic parameters in a meaningful way without breaking backwards compatibility of the DynaBeanMapDecorator class: A map wrapping a DynaBean should be of type Map<String, Object>. However, when using these generic parameters in DynaBeanMapDecorator this would be an incompatible change (as method signatures would have to be adapted). To solve this problem, this generic base class is added which allows specifying the key type as parameter. This makes it easy to have a new subclass using the correct generic parameters while DynaBeanMapDecorator could still remain with compatible parameters.

Since:

BeanUtils 1.9.0

Version:

$Id$

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
BaseDynaBeanMapDecorator(DynaBean dynaBean) Constructs a read only Map for the specified DynaBean.
BaseDynaBeanMapDecorator(DynaBean dynaBean, boolean readOnly) Construct a Map for the specified DynaBean.

Method Summary

Modifier and Type	Method and Description
void	clear() clear() operation is not supported.
boolean	containsKey(Object key) Indicate whether the DynaBean contains a specified value for one (or more) of its properties.
boolean	containsValue(Object value) Indicates whether the decorated DynaBean contains a specified value.
protected abstract K	convertKey(String propertyName) Converts the name of a property to the key type of this decorator.
Set<Map.Entry<K,Object>>	entrySet() Returns the Set of the property/value mappings in the decorated DynaBean.
Object	get(Object key) Return the value for the specified key from the decorated DynaBean.
DynaBean	getDynaBean() Provide access to the underlying DynaBean this Map decorates.
boolean	isEmpty() Indicate whether the decorated DynaBean has any properties.
boolean	isReadOnly() Indicate whether the Map is read only.
Set<K>	keySet() Returns the Set of the property names in the decorated DynaBean.
Object	put(K key, Object value) Set the value for the specified property in the decorated DynaBean.
void	putAll(Map<? extends K,? extends Object> map) Copy the contents of a Map to the decorated DynaBean.
Object	remove(Object key) remove() operation is not supported.
int	size() Returns the number properties in the decorated DynaBean.
Collection<Object>	values() Returns the set of property values in the decorated DynaBean.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

BaseDynaBeanMapDecorator

public BaseDynaBeanMapDecorator(DynaBean dynaBean)

Constructs a read only Map for the specified DynaBean.

Parameters:

dynaBean - The dyna bean being decorated

Throws:

IllegalArgumentException - if the DynaBean is null.

BaseDynaBeanMapDecorator

public BaseDynaBeanMapDecorator(DynaBean dynaBean,
                                boolean readOnly)

Construct a Map for the specified DynaBean.

Parameters:

dynaBean - The dyna bean being decorated

readOnly - true if the Map is read only otherwise false

Throws:

IllegalArgumentException - if the DynaBean is null.

Method Detail

isReadOnly

public boolean isReadOnly()

Indicate whether the Map is read only.

Returns:

true if the Map is read only, otherwise false.

clear

public void clear()

clear() operation is not supported.

Specified by:

clear in interface Map<K,Object>

Throws:

UnsupportedOperationException

containsKey

public boolean containsKey(Object key)

Indicate whether the DynaBean contains a specified value for one (or more) of its properties.

Specified by:

containsKey in interface Map<K,Object>

Parameters:

key - The DynaBean's property name

Returns:

true if one of the DynaBean's properties contains a specified value.

containsValue

public boolean containsValue(Object value)

Indicates whether the decorated DynaBean contains a specified value.

Specified by:

containsValue in interface Map<K,Object>

Parameters:

value - The value to check for.

Returns:

true if one of the the DynaBean's properties contains the specified value, otherwise false.

entrySet

public Set<Map.Entry<K,Object>> entrySet()

Returns the Set of the property/value mappings in the decorated DynaBean.

Each element in the Set is a Map.Entry type.

Specified by:

entrySet in interface Map<K,Object>

Returns:

An unmodifiable set of the DynaBean property name/value pairs

get

public Object get(Object key)

Return the value for the specified key from the decorated DynaBean.

Specified by:

get in interface Map<K,Object>

Parameters:

key - The DynaBean's property name

Returns:

The value for the specified property.

isEmpty

public boolean isEmpty()

Indicate whether the decorated DynaBean has any properties.

Specified by:

isEmpty in interface Map<K,Object>

Returns:

true if the DynaBean has no properties, otherwise false.

keySet

public Set<K> keySet()

Returns the Set of the property names in the decorated DynaBean.

N.B.For DynaBeans whose associated DynaClass is a MutableDynaClass a new Set is created every time, otherwise the Set is created only once and cached.

Specified by:

keySet in interface Map<K,Object>

Returns:

An unmodifiable set of the DynaBeans property names.

put

public Object put(K key,
                  Object value)

Set the value for the specified property in the decorated DynaBean.

Specified by:

put in interface Map<K,Object>

Parameters:

key - The DynaBean's property name

value - The value for the specified property.

Returns:

The previous property's value.

Throws:

UnsupportedOperationException - if isReadOnly() is true.

putAll

public void putAll(Map<? extends K,? extends Object> map)

Copy the contents of a Map to the decorated DynaBean.

Specified by:

putAll in interface Map<K,Object>

Parameters:

map - The Map of values to copy.

Throws:

UnsupportedOperationException - if isReadOnly() is true.

remove

public Object remove(Object key)

remove() operation is not supported.

Specified by:

remove in interface Map<K,Object>

Parameters:

key - The DynaBean's property name

Returns:

the value removed

Throws:

UnsupportedOperationException

size

public int size()

Returns the number properties in the decorated DynaBean.

Specified by:

size in interface Map<K,Object>

Returns:

The number of properties.

values

public Collection<Object> values()

Returns the set of property values in the decorated DynaBean.

Specified by:

values in interface Map<K,Object>

Returns:

Unmodifiable collection of values.

getDynaBean

public DynaBean getDynaBean()

Provide access to the underlying DynaBean this Map decorates.

Returns:

the decorated DynaBean.

convertKey

protected abstract K convertKey(String propertyName)

Converts the name of a property to the key type of this decorator.

Parameters:

propertyName - the name of a property

Returns:

the converted key to be used in the decorated map