org.apache.commons.beanutils
Class LazyDynaMap

java.lang.Object
  org.apache.commons.beanutils.LazyDynaBean
      org.apache.commons.beanutils.LazyDynaMap

All Implemented Interfaces:

Serializable, DynaBean, DynaClass, MutableDynaClass

public class LazyDynaMap
extends LazyDynaBean
implements MutableDynaClass

Provides a light weight DynaBean facade to a Map with lazy map/list processing.

Its a light weight DynaBean implementation because there is no actual DynaClass associated with this DynaBean - in fact it implements the DynaClass interface itself providing pseudo DynaClass behaviour from the actual values stored in the Map.

As well providing rhe standard DynaBean access to the Map's properties this class also provides the usual Lazy behaviour:

• Properties don't need to be pre-defined in a DynaClass
• Indexed properties (Lists or Arrays) are automatically instantiated and grown so that they are large enough to cater for the index being set.
• Mapped properties are automatically instantiated.

Restricted DynaClass

This class implements the MutableDynaClass interface. MutableDynaClass have a facility to restrict the DynaClass so that its properties cannot be modified. If the MutableDynaClass is restricted then calling any of the set() methods for a property which doesn't exist will result in a IllegalArgumentException being thrown.

Author:

Niall Pemberton

See Also:

Serialized Form

Field Summary

protected String	name The name of this DynaClass (analogous to the getName() method of java.lang.Class).
protected boolean	restricted Controls whether changes to this DynaClass's properties are allowed.
protected boolean	returnNull Controls whether the getDynaProperty() method returns null if a property doesn't exist - or creates a new one.

Fields inherited from class org.apache.commons.beanutils.LazyDynaBean

BigDecimal_ZERO, BigInteger_ZERO, Byte_ZERO, Character_SPACE, Double_ZERO, dynaClass, Float_ZERO, Integer_ZERO, Long_ZERO, Short_ZERO, values

Constructor Summary

LazyDynaMap()
Default Constructor.

LazyDynaMap(DynaClass dynaClass)
Construct a new LazyDynaMap based on an exisiting DynaClass

LazyDynaMap(DynaProperty[] properties)
Construct a new LazyDynaMap with the specified properties.

LazyDynaMap(Map values)
Construct a new LazyDynaMap with the specified Map.

LazyDynaMap(String name)
Construct a new LazyDynaMap with the specified name.

LazyDynaMap(String name, DynaProperty[] properties)
Construct a new LazyDynaMap with the specified name and properties.

LazyDynaMap(String name, Map values)
Construct a new LazyDynaMap with the specified name and Map.

Method Summary

protected void	add(DynaProperty property) Add a new dynamic property.
void	add(String name) Add a new dynamic property with no restrictions on data type, readability, or writeability.
void	add(String name, Class type) Add a new dynamic property with the specified data type, but with no restrictions on readability or writeability.
void	add(String name, Class type, boolean readable, boolean writeable) Add a new dynamic property with the specified data type, readability, and writeability.
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.
Map	getMap() Return the underlying Map backing this DynaBean
String	getName() Return the name of this DynaClass (analogous to the getName() method of java.lang.Class
protected boolean	isDynaProperty(String name) Indicate whether a property actually exists.
boolean	isRestricted() Is this DynaClass currently restricted.
boolean	isReturnNull() Should this DynaClass return a null from the getDynaProperty(name) method if the property doesn't exist.
DynaBean	newInstance() Instantiate and return a new DynaBean instance, associated with this DynaClass.
void	remove(String name) Remove the specified dynamic property, and any associated data type, readability, and writeability, from this dynamic class.
void	set(String name, Object value) Set the value of a simple property with the specified name.
void	setMap(Map values) Set the Map backing this DynaBean
void	setRestricted(boolean restricted) Set whether this DynaClass is currently restricted.
void	setReturnNull(boolean returnNull) Set whether this DynaClass should return a null from the getDynaProperty(name) method if the property doesn't exist.

Methods inherited from class org.apache.commons.beanutils.LazyDynaBean

contains, createDynaBeanProperty, createIndexedProperty, createMappedProperty, createNumberProperty, createOtherProperty, createPrimitiveProperty, createProperty, defaultIndexedProperty, defaultMappedProperty, get, get, get, getDynaClass, growIndexedProperty, isAssignable, newMap, remove, set, set, size

Methods inherited from class java.lang.Object

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

Field Detail

name

protected String name

The name of this DynaClass (analogous to the getName() method of java.lang.Class).

restricted

protected boolean restricted

Controls whether changes to this DynaClass's properties are allowed.

returnNull

protected boolean returnNull

Controls whether the getDynaProperty() method returns null if a property doesn't exist - or creates a new one.

Default is false.

Constructor Detail

LazyDynaMap

public LazyDynaMap()

Default Constructor.

LazyDynaMap

public LazyDynaMap(String name)

Construct a new LazyDynaMap with the specified name.

Parameters:

name - Name of this DynaBean class

LazyDynaMap

public LazyDynaMap(Map values)

Construct a new LazyDynaMap with the specified Map.

Parameters:

values - The Map backing this LazyDynaMap

LazyDynaMap

public LazyDynaMap(String name,
                   Map values)

Construct a new LazyDynaMap with the specified name and Map.

Parameters:

name - Name of this DynaBean class

values - The Map backing this LazyDynaMap

LazyDynaMap

public LazyDynaMap(DynaProperty[] properties)

Construct a new LazyDynaMap with the specified properties.

Parameters:

properties - Property descriptors for the supported properties

LazyDynaMap

public LazyDynaMap(String name,
                   DynaProperty[] properties)

Construct a new LazyDynaMap with the specified name and properties.

Parameters:

name - Name of this DynaBean class

properties - Property descriptors for the supported properties

LazyDynaMap

public LazyDynaMap(DynaClass dynaClass)

Construct a new LazyDynaMap based on an exisiting DynaClass

Parameters:

dynaClass - DynaClass to copy the name and properties from

Method Detail

setMap

public void setMap(Map values)

Set the Map backing this DynaBean

Parameters:

values - The new Map of values

getMap

public Map getMap()

Return the underlying Map backing this DynaBean

Overrides:

getMap in class LazyDynaBean

Returns:

the underlying Map

Since:

1.8.0

set

public void set(String name,
                Object value)

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

Specified by:

set in interface DynaBean

Overrides:

set in class LazyDynaBean

Parameters:

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

value - Value to which this property is to be set

getName

public String getName()

Return the name of this DynaClass (analogous to the getName() method of java.lang.Class

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 the property is not found and the returnNull indicator is true, this method always returns null.

If the property is not found and the returnNull indicator is false a new property descriptor is created and returned (although its not actually added to the DynaClass's properties). This is the default beahviour.

The reason for not returning a null property descriptor is that BeanUtils uses this method to check if a property exists before trying to set it - since these Map implementations automatically add any new properties when they are set, returning null from this method would defeat their purpose.

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()

Instantiate and return a new DynaBean instance, associated with this DynaClass.

Specified by:

newInstance in interface DynaClass

Returns:

A new DynaBean instance

isRestricted

public boolean isRestricted()

Is this DynaClass currently restricted.

If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.

Specified by:

isRestricted in interface MutableDynaClass

Returns:

true if this Mutable DynaClass is restricted, otherwise false

setRestricted

public void setRestricted(boolean restricted)

Set whether this DynaClass is currently restricted.

If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.

Specified by:

setRestricted in interface MutableDynaClass

Parameters:

restricted - The new restricted state

add

public void add(String name)

Add a new dynamic property with no restrictions on data type, readability, or writeability.

Specified by:

add in interface MutableDynaClass

Parameters:

name - Name of the new dynamic property

Throws:

IllegalArgumentException - if name is null

add

public void add(String name,
                Class type)

Add a new dynamic property with the specified data type, but with no restrictions on readability or writeability.

Specified by:

add in interface MutableDynaClass

Parameters:

name - Name of the new dynamic property

type - Data type of the new dynamic property (null for no restrictions)

Throws:

IllegalArgumentException - if name is null

IllegalStateException - if this DynaClass is currently restricted, so no new properties can be added

add

public void add(String name,
                Class type,
                boolean readable,
                boolean writeable)

Add a new dynamic property with the specified data type, readability, and writeability.

N.B.Support for readable/writeable properties has not been implemented and this method always throws a UnsupportedOperationException.

I'm not sure the intention of the original authors for this method, but it seems to me that readable/writable should be attributes of the DynaProperty class (which they are not) and is the reason this method has not been implemented.

Specified by:

add in interface MutableDynaClass

Parameters:

name - Name of the new dynamic property

type - Data type of the new dynamic property (null for no restrictions)

readable - Set to true if this property value should be readable

writeable - Set to true if this property value should be writeable

Throws:

UnsupportedOperationException - anytime this method is called

add

protected void add(DynaProperty property)

Add a new dynamic property.

Parameters:

property - Property the new dynamic property to add.

Throws:

IllegalArgumentException - if name is null

remove

public void remove(String name)

Remove the specified dynamic property, and any associated data type, readability, and writeability, from this dynamic class. NOTE - This does NOT cause any corresponding property values to be removed from DynaBean instances associated with this DynaClass.

Specified by:

remove in interface MutableDynaClass

Parameters:

name - Name of the dynamic property to remove

Throws:

IllegalArgumentException - if name is null

IllegalStateException - if this DynaClass is currently restricted, so no properties can be removed

isReturnNull

public boolean isReturnNull()

Should this DynaClass return a null from the getDynaProperty(name) method if the property doesn't exist.

Returns:

true if a null DynaProperty should be returned if the property doesn't exist, otherwise false if a new DynaProperty should be created.

setReturnNull

public void setReturnNull(boolean returnNull)

Set whether this DynaClass should return a null from the getDynaProperty(name) method if the property doesn't exist.

Parameters:

returnNull - true if a null DynaProperty should be returned if the property doesn't exist, otherwise false if a new DynaProperty should be created.

isDynaProperty

protected boolean isDynaProperty(String name)

Indicate whether a property actually exists.

N.B. Using getDynaProperty(name) == null doesn't work in this implementation because that method might return a DynaProperty if it doesn't exist (depending on the returnNull indicator).

Overrides:

isDynaProperty in class LazyDynaBean

Parameters:

name - Name of the dynamic property

Returns:

true if the property exists, otherwise false

Throws:

IllegalArgumentException - if no property name is specified