org.apache.commons.beanutils
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.
See Also: LazyDynaBean
Field Summary | |
---|---|
protected boolean | restricted
Controls whether changes to this DynaClass's properties are allowed. |
protected boolean | returnNull Controls whether the Default is |
Constructor Summary | |
---|---|
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, DynaProperty[] properties)
Construct a new LazyDynaClass with the specified name and properties.
| |
LazyDynaClass(String name, Class dynaBeanClass, DynaProperty[] properties)
Construct a new LazyDynaClass with the specified name, DynaBean class and properties.
|
Method Summary | |
---|---|
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. N.B.Support for readable/writeable properties has not been implemented
and this method always throws a 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 |
protected void | add(DynaProperty property)
Add a new dynamic property.
|
DynaProperty | getDynaProperty(String name) Return a property descriptor for the specified property. If the property is not found and the If the property is not found and the |
boolean | isDynaProperty(String name) Indicate whether a property actually exists. N.B. Using |
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. |
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. If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed. |
void | setReturnNull(boolean returnNull)
Set whether this DynaClass should return a null from
the getDynaProperty(name) method if the property
doesn't exist. |
Controls whether the getDynaProperty()
method returns
null if a property doesn't exist - or creates a new one.
Default is false
.
Parameters: name Name of this DynaBean class
Parameters: name Name of this DynaBean class dynaBeanClass The implementation class for new instances
Parameters: name Name of this DynaBean class properties Property descriptors for the supported properties
Parameters: name Name of this DynaBean class dynaBeanClass The implementation class for new intances properties Property descriptors for the supported properties
Parameters: name Name of the new dynamic property
Throws: IllegalArgumentException if name is null IllegalStateException if this DynaClass is currently restricted, so no new properties can be added
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 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.
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
Parameters: property Property the new dynamic property to add.
Throws: IllegalArgumentException if name is null IllegalStateException if this DynaClass is currently restricted, so no new properties can be added
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.
Parameters: name Name of the dynamic property for which a descriptor is requested
Throws: IllegalArgumentException if no property name is specified
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).
Throws: IllegalArgumentException if no property name is specified
Is this DynaClass currently restricted.
If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.
null
from
the getDynaProperty(name)
method if the property
doesn't exist.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
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.
null
from
the getDynaProperty(name)
method if the property
doesn't exist.