DynaBean which automatically adds properties to the
DynaClass
and provides
Lazy List and
Lazy Map features.
DynaBeans deal with three types of properties -
simple,
indexed and
mapped and
have the following
get()
and
set()
methods for
each of these types:
- Simple property methods -
get(name)
and
set(name, value)
- Indexed property methods -
get(name, index)
and
set(name, index, value)
- Mapped property methods -
get(name, key)
and
set(name, key, value)
Getting Property Values
Calling any of the
get()
methods, for a property which
doesn't exist, returns
null
in this implementation.
Setting Simple Properties
The
LazyDynaBean
will automatically add a property to the
DynaClass
if it doesn't exist when the
set(name, value)
method is called.
DynaBean myBean = new LazyDynaBean();
myBean.set("myProperty", "myValue");
Setting Indexed Properties
If the property
doesn't exist, the
LazyDynaBean
will automatically add
a property with an
ArrayList
type to the
DynaClass
when
the
set(name, index, value)
method is called.
It will also instantiate a new
ArrayList
and automatically
grow
the
List
so that it is big enough to accomodate the index being set.
ArrayList
is the default indexed property that LazyDynaBean uses but
this can be easily changed by overriding the
defaultIndexedProperty(name)
method.
DynaBean myBean = new LazyDynaBean();
myBean.set("myIndexedProperty", 0, "myValue1");
myBean.set("myIndexedProperty", 1, "myValue2");
If the indexed property
does exist in the
DynaClass
but is set to
null
in the
LazyDynaBean
, then it will instantiate a
new
List
or
Array
as specified by the property's type
in the
DynaClass
and automatically
grow the
List
or
Array
so that it is big enough to accomodate the index being set.
DynaBean myBean = new LazyDynaBean();
MutableDynaClass myClass = (MutableDynaClass)myBean.getDynaClass();
myClass.add("myIndexedProperty", int[].class);
myBean.set("myIndexedProperty", 0, new Integer(10));
myBean.set("myIndexedProperty", 1, new Integer(20));
Setting Mapped Properties
If the property
doesn't exist, the
LazyDynaBean
will automatically add
a property with a
HashMap
type to the
DynaClass
and
instantiate a new
HashMap
in the DynaBean when the
set(name, key, value)
method is called.
HashMap
is the default
mapped property that LazyDynaBean uses but this can be easily changed by overriding
the
defaultMappedProperty(name)
method.
DynaBean myBean = new LazyDynaBean();
myBean.set("myMappedProperty", "myKey", "myValue");
If the mapped property
does exist in the
DynaClass
but is set to
null
in the
LazyDynaBean
, then it will instantiate a
new
Map
as specified by the property's type in the
DynaClass
.
DynaBean myBean = new LazyDynaBean();
MutableDynaClass myClass = (MutableDynaClass)myBean.getDynaClass();
myClass.add("myMappedProperty", TreeMap.class);
myBean.set("myMappedProperty", "myKey", "myValue");
Restricted DynaClass
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.
BigDecimal_ZERO
protected static final BigDecimal BigDecimal_ZERO
BigDecimal Zero
BigInteger_ZERO
protected static final BigInteger BigInteger_ZERO
BigInteger Zero
Byte_ZERO
protected static final Byte Byte_ZERO
Byte Zero
Character_SPACE
protected static final Character Character_SPACE
Character Space
Double_ZERO
protected static final Double Double_ZERO
Double Zero
Float_ZERO
protected static final Float Float_ZERO
Float Zero
Integer_ZERO
protected static final Integer Integer_ZERO
Integer Zero
Long_ZERO
protected static final Long Long_ZERO
Long Zero
Short_ZERO
protected static final Short Short_ZERO
Short Zero
dynaClass
protected MutableDynaClass dynaClass
The MutableDynaClass
"base class" that this DynaBean
is associated with.
logger
private Log logger
Commons Logging
mapDecorator
private Map mapDecorator
Map decorator for this DynaBean
values
protected Map values
The MutableDynaClass
"base class" that this DynaBean
is associated with.
contains
public boolean contains(String name,
String key)
Does the specified mapped property contain a value for the specified
key value?
- contains in interface DynaBean
name
- Name of the property to checkkey
- Name of the key to check
true
if the mapped property contains a value for
the specified key, otherwise
false
createDynaBeanProperty
protected Object createDynaBeanProperty(String name,
Class type)
Create a new Instance of a 'DynaBean' Property.
name
- The name of the propertytype
- The class of the property
createIndexedProperty
protected Object createIndexedProperty(String name,
Class type)
Create a new Instance of an 'Indexed' Property
name
- The name of the propertytype
- The class of the property
createMappedProperty
protected Object createMappedProperty(String name,
Class type)
Create a new Instance of a 'Mapped' Property
name
- The name of the propertytype
- The class of the property
createNumberProperty
protected Object createNumberProperty(String name,
Class type)
Create a new Instance of a java.lang.Number
Property.
name
- The name of the propertytype
- The class of the property
createOtherProperty
protected Object createOtherProperty(String name,
Class type)
Create a new Instance of other Property types
name
- The name of the propertytype
- The class of the property
createPrimitiveProperty
protected Object createPrimitiveProperty(String name,
Class type)
Create a new Instance of a 'Primitive' Property.
name
- The name of the propertytype
- The class of the property
createProperty
protected Object createProperty(String name,
Class type)
Create a new Instance of a Property
name
- The name of the propertytype
- The class of the property
defaultIndexedProperty
protected Object defaultIndexedProperty(String name)
Creates a new
ArrayList
for an 'indexed' property
which doesn't exist.
This method shouls be overriden if an alternative
List
or
Array
implementation is required for 'indexed' properties.
name
- Name of the 'indexed property.
- The default value for an indexed property (java.util.ArrayList)
defaultMappedProperty
protected Map defaultMappedProperty(String name)
Creates a new
HashMap
for a 'mapped' property
which doesn't exist.
This method can be overriden if an alternative
Map
implementation is required for 'mapped' properties.
name
- Name of the 'mapped property.
- The default value for a mapped property (java.util.HashMap)
get
public Object get(String name)
Return the value of a simple property with the specified name.
N.B. Returns
null
if there is no property
of the specified name.
- get in interface DynaBean
name
- Name of the property whose value is to be retrieved.
get
public Object get(String name,
String key)
Return the value of a mapped property with the specified name.
N.B. Returns
null
if there is no 'mapped'
property of the specified name.
- get in interface DynaBean
name
- Name of the property whose value is to be retrievedkey
- Key of the value to be retrieved
- The mapped property's value
get
public Object get(String name,
int index)
Return the value of an indexed property with the specified name.
N.B. Returns
null
if there is no 'indexed'
property of the specified name.
- get in interface DynaBean
name
- Name of the property whose value is to be retrievedindex
- Index of the value to be retrieved
- The indexed property's value
getDynaClass
public DynaClass getDynaClass()
Return the DynaClass
instance that describes the set of
properties available for this DynaBean.
- getDynaClass in interface DynaBean
getMap
public Map getMap()
Return a Map representation of this DynaBean.
This, for example, could be used in JSTL in the following way to access
a DynaBean's
fooProperty
:
${myDynaBean.map.fooProperty}
- a Map representation of this DynaBean
growIndexedProperty
protected Object growIndexedProperty(String name,
Object indexedProperty,
int index)
Grow the size of an indexed property
name
- The name of the propertyindexedProperty
- The current property valueindex
- The indexed value to grow the property to (i.e. one less than
the required size)
- The new property value (grown to the appropriate size)
isAssignable
protected boolean isAssignable(Class dest,
Class source)
Is an object of the source class assignable to the destination class?
dest
- Destination classsource
- Source class
true
if the source class is assignable to the
destination class, otherwise
false
isDynaProperty
protected boolean isDynaProperty(String name)
Indicates if there is a property with the specified name.
name
- The name of the property to check
true
if there is a property of the
specified name, otherwise
false
logger
private Log logger()
Returns the Log
.
newMap
protected Map newMap()
Creates a new instance of the Map
.
remove
public void remove(String name,
String key)
Remove any existing value for the specified key on the
specified mapped property.
- remove in interface DynaBean
name
- Name of the property for which a value is to
be removedkey
- Key of the value to be removed
set
public void set(String name,
Object value)
Set the value of a simple property with the specified name.
- set in interface DynaBean
name
- Name of the property whose value is to be setvalue
- Value to which this property is to be set
set
public void set(String name,
String key,
Object value)
Set the value of a mapped property with the specified name.
- set in interface DynaBean
name
- Name of the property whose value is to be setkey
- Key of the property to be setvalue
- Value to which this property is to be set
set
public void set(String name,
int index,
Object value)
Set the value of an indexed property with the specified name.
- set in interface DynaBean
name
- Name of the property whose value is to be setindex
- Index of the property to be setvalue
- Value to which this property is to be set
size
public int size(String name)
Return the size of an indexed or mapped property.
name
- Name of the property
- The indexed or mapped property size