An implementation of Map for JavaBeans which uses introspection to
get and put properties in the bean.
If an exception occurs during attempts to get or set a property then the
property is considered non existent in the Map
clear
public void clear()
This method reinitializes the bean map to have default values for the
bean's properties. This is accomplished by constructing a new instance
of the bean which the map uses as its underlying data source. This
behavior for clear()
differs from the Map contract in that
the mappings are not actually removed from the map (the mappings for a
BeanMap are fixed).
clone
public Object clone()
throws CloneNotSupportedException
Clone this bean map using the following process:
- If there is no underlying bean, return a cloned BeanMap without a
bean.
- Since there is an underlying bean, try to instantiate a new bean of
the same type using Class.newInstance().
- If the instantiation fails, throw a CloneNotSupportedException
- Clone the bean map and set the newly instantiated bean as the
underlying bean for the bean map.
- Copy each property that is both readable and writable from the
existing object to a cloned bean map.
- If anything fails along the way, throw a
CloneNotSupportedException.
containsKey
public boolean containsKey(Object name)
Returns true if the bean defines a property with the given name.
The given name must be a
String
; if not, this method
returns false. This method will also return false if the bean
does not define a property with that name.
Write-only properties will not be matched as the test operates against
property read methods.
name
- the name of the property to check
- false if the given name is null or is not a
String
;
false if the bean does not define a property with that name; or
true if the bean does define a property with that name
containsValue
public boolean containsValue(Object value)
Returns true if the bean defines a property whose current value is
the given object.
value
- the value to check
- false true if the bean has at least one property whose
current value is that object, false otherwise
convertType
protected Object convertType(Class newType,
Object value)
throws InstantiationException,
IllegalAccessException,
IllegalArgumentException,
InvocationTargetException
Converts the given value to the given type. First, reflection is
is used to find a public constructor declared by the given class
that takes one argument, which must be the precise type of the
given value. If such a constructor is found, a new object is
created by passing the given value to that constructor, and the
newly constructed object is returned.
If no such constructor exists, and the given type is a primitive
type, then the given value is converted to a string using its
toString()
method, and that string is
parsed into the correct primitive type using, for instance,
Integer.valueOf(String)
to convert the string into an
int
.
If no special constructor exists and the given type is not a
primitive type, this method returns the original value.
newType
- the type to convert the value tovalue
- the value to convert
createWriteMethodArguments
protected Object[] createWriteMethodArguments(Method method,
Object value)
throws IllegalAccessException,
ClassCastException
Creates an array of parameters to pass to the given mutator method.
If the given object is not the right type to pass to the method
directly, it will be converted using
convertType(Class,Object)
.
method
- the mutator methodvalue
- the value to pass to the mutator method
- an array containing one object that is either the given value
or a transformed value
entryIterator
public Iterator entryIterator()
Convenience method for getting an iterator over the entries.
- an iterator over the entries
entrySet
public Set entrySet()
Gets a Set of MapEntry objects that are the mappings for this BeanMap.
Each MapEntry can be set but not removed.
- the unmodifiable set of mappings
firePropertyChange
protected void firePropertyChange(Object key,
Object oldValue,
Object newValue)
Called during a successful
put(Object,Object)
operation.
Default implementation does nothing. Override to be notified of
property changes in the bean caused by this map.
key
- the name of the property that changedoldValue
- the old value for that propertynewValue
- the new value for that property
get
public Object get(Object name)
Returns the value of the bean's property with the given name.
The given name must be a
String
and must not be
null; otherwise, this method returns
null
.
If the bean defines a property with the given name, the value of
that property is returned. Otherwise,
null
is
returned.
Write-only properties will not be matched as the test operates against
property read methods.
name
- the name of the property whose value to return
- the value of the property with that name
getBean
public Object getBean()
Returns the bean currently being operated on. The return value may
be null if this map is empty.
- the bean being operated on by this map
getReadMethod
protected Method getReadMethod(Object name)
Returns the accessor for the property with the given name.
name
- the name of the property
- null if the name is null; null if the name is not a
String
; null if no such property exists; or the accessor
method for that property
getReadMethod
public Method getReadMethod(String name)
Returns the accessor for the property with the given name.
name
- the name of the property
- the accessor method for the property, or null
getType
public Class getType(String name)
Returns the type of the property with the given name.
name
- the name of the property
- the type of the property, or
null
if no such
property exists
getTypeTransformer
protected Transformer getTypeTransformer(Class aType)
Returns a transformer for the given primitive type.
aType
- the primitive type whose transformer to return
- a transformer that will convert strings into that type,
or null if the given type is not a primitive type
getWriteMethod
protected Method getWriteMethod(Object name)
Returns the mutator for the property with the given name.
- null if the name is null; null if the name is not a
String
; null if no such property exists; null if the
property is read-only; or the mutator method for that property
getWriteMethod
public Method getWriteMethod(String name)
Returns the mutator for the property with the given name.
name
- the name of the property
- the mutator method for the property, or null
keyIterator
public Iterator keyIterator()
Convenience method for getting an iterator over the keys.
Write-only properties will not be returned in the iterator.
- an iterator over the keys
keySet
public Set keySet()
Get the keys for this BeanMap.
Write-only properties are
not included in the returned set of
property names, although it is possible to set their value and to get
their type.
- BeanMap keys. The Set returned by this method is not
modifiable.
logInfo
protected void logInfo(Exception ex)
Logs the given exception to System.out
. Used to display
warnings while accessing/mutating the bean.
ex
- the exception to log
logWarn
protected void logWarn(Exception ex)
Logs the given exception to System.err
. Used to display
errors while accessing/mutating the bean.
ex
- the exception to log
put
public Object put(Object name,
Object value)
throws IllegalArgumentException,
ClassCastException
Sets the bean property with the given name to the given value.
name
- the name of the property to setvalue
- the value to set that property to
- the previous value of that property
putAllWriteable
public void putAllWriteable(BeanMap map)
Puts all of the writable properties from the given BeanMap into this
BeanMap. Read-only and Write-only properties will be ignored.
map
- the BeanMap whose properties to put
reinitialise
protected void reinitialise()
Reinitializes this bean. Called during
setBean(Object)
.
Does introspection to find properties.
setBean
public void setBean(Object newBean)
Sets the bean to be operated on by this map. The given value may
be null, in which case this map will be empty.
newBean
- the new bean to operate on
size
public int size()
Returns the number of properties defined by the bean.
- the number of properties defined by the bean
toString
public String toString()
valueIterator
public Iterator valueIterator()
Convenience method for getting an iterator over the values.
- an iterator over the values
values
public Collection values()
Returns the values for the BeanMap.
- values for the BeanMap. The returned collection is not
modifiable.