public class LazyDynaClass extends BasicDynaClass implements MutableDynaClass
DynaClass which implements the MutableDynaClass
interface.
A MutableDynaClass
is a specialized extension to DynaClass
that allows properties to be added or removed dynamically.
This implementation has one slightly unusual default behaviour - calling
the getDynaProperty(name)
method for a property which doesn't
exist returns a DynaProperty
rather than null
. The
reason for this is that BeanUtils
calls this method to check if
a property exists before trying to set the value. This would defeat the object
of the LazyDynaBean
which automatically adds missing properties
when any of its set()
methods are called. For this reason the
isDynaProperty(name)
method has been added to this implementation
in order to determine if a property actually exists. If the more normal
behaviour of returning null
is required, then this can be achieved
by calling the setReturnNull(true)
.
The add(name, type, readable, writable)
method is not implemented
and always throws an UnsupportedOperationException
. I believe
this attributes need to be added to the DynaProperty
class
in order to control read/write facilities.
LazyDynaBean
,
Serialized FormModifier and Type | Field and Description |
---|---|
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. |
constructor, constructorTypes, constructorValues, dynaBeanClass, name, properties, propertiesMap
Constructor and Description |
---|
LazyDynaClass()
Construct a new LazyDynaClass with default parameters.
|
LazyDynaClass(String name)
Construct a new LazyDynaClass with the specified name.
|
LazyDynaClass(String name,
Class<?> dynaBeanClass)
Construct a new LazyDynaClass with the specified name and DynaBean class.
|
LazyDynaClass(String name,
Class<?> dynaBeanClass,
DynaProperty[] properties)
Construct a new LazyDynaClass with the specified name, DynaBean class and properties.
|
LazyDynaClass(String name,
DynaProperty[] properties)
Construct a new LazyDynaClass with the specified name and properties.
|
Modifier and Type | Method and Description |
---|---|
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 |
getDynaProperty(String name)
Return a property descriptor for the specified property.
|
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. |
void |
remove(String name)
Remove the specified dynamic property, and any associated data type,
readability, and writeability, from this dynamic class.
|
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. |
getDynaBeanClass, getDynaProperties, getName, newInstance, setDynaBeanClass, setProperties
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
getDynaProperties, getName, newInstance
protected boolean restricted
protected boolean returnNull
Controls whether the getDynaProperty()
method returns
null if a property doesn't exist - or creates a new one.
Default is false
.
public LazyDynaClass()
public LazyDynaClass(String name)
name
- Name of this DynaBean classpublic LazyDynaClass(String name, Class<?> dynaBeanClass)
name
- Name of this DynaBean classdynaBeanClass
- The implementation class for new instancespublic LazyDynaClass(String name, DynaProperty[] properties)
name
- Name of this DynaBean classproperties
- Property descriptors for the supported propertiespublic LazyDynaClass(String name, Class<?> dynaBeanClass, DynaProperty[] properties)
name
- Name of this DynaBean classdynaBeanClass
- The implementation class for new instancesproperties
- Property descriptors for the supported propertiespublic 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.
isRestricted
in interface MutableDynaClass
true
if this MutableDynaClass
cannot be changed
otherwise false
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.
setRestricted
in interface MutableDynaClass
restricted
- true
if this MutableDynaClass
cannot
be changed otherwise false
public boolean isReturnNull()
null
from
the getDynaProperty(name)
method if the property
doesn't exist.true
if a null
DynaProperty
should be returned if the property doesn't exist, otherwise
false
if a new DynaProperty
should be created.public void setReturnNull(boolean returnNull)
null
from
the getDynaProperty(name)
method if the property
doesn't exist.returnNull
- true
if a null
DynaProperty
should be returned if the property doesn't exist, otherwise
false
if a new DynaProperty
should be created.public void add(String name)
add
in interface MutableDynaClass
name
- Name of the new dynamic propertyIllegalArgumentException
- if name is nullIllegalStateException
- if this DynaClass is currently
restricted, so no new properties can be addedpublic void add(String name, Class<?> type)
add
in interface MutableDynaClass
name
- Name of the new dynamic propertytype
- Data type of the new dynamic property (null for no
restrictions)IllegalArgumentException
- if name is nullIllegalStateException
- if this DynaClass is currently
restricted, so no new properties can be addedpublic 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.
add
in interface MutableDynaClass
name
- Name of the new dynamic propertytype
- Data type of the new dynamic property (null for no
restrictions)readable
- Set to true
if this property value
should be readablewriteable
- Set to true
if this property value
should be writeableUnsupportedOperationException
- anytime this method is calledprotected void add(DynaProperty property)
property
- Property the new dynamic property to add.IllegalArgumentException
- if name is nullIllegalStateException
- if this DynaClass is currently
restricted, so no new properties can be addedpublic void remove(String name)
remove
in interface MutableDynaClass
name
- Name of the dynamic property to removeIllegalArgumentException
- if name is nullIllegalStateException
- if this DynaClass is currently
restricted, so no properties can be removedpublic 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 Lazy implementations automatically
add any new properties when they are set, returning null
from
this method would defeat their purpose.
getDynaProperty
in interface DynaClass
getDynaProperty
in class BasicDynaClass
name
- Name of the dynamic property for which a descriptor
is requestedIllegalArgumentException
- if no property name is specifiedpublic 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).
name
- The name of the property to checktrue
if there is a property of the
specified name, otherwise false
IllegalArgumentException
- if no property name is specifiedCopyright © 2000–2019 The Apache Software Foundation. All rights reserved.