ch.agent.crnickl.impl

Class PropertyImpl<T>

java.lang.Object

ch.agent.crnickl.impl.DBObjectImpl

ch.agent.crnickl.impl.PropertyImpl<T>

Type Parameters:

T - the underlying data type of attributes having this property

All Implemented Interfaces:

DBObject, Property<T>

Direct Known Subclasses:

UpdatablePropertyImpl

public class PropertyImpl<T>
extends DBObjectImpl
implements Property<T>

Default implementation of Property.

Author:

Jean-Paul Vetterli

Constructor Summary

Constructors

Constructor and Description
PropertyImpl(String name, ValueType<T> valueType, boolean indexed, Surrogate surrogate) Construct a Property.

Method Summary

Modifier and Type	Method and Description
void	check(T value) Check the value for conformity with the ValueType.
UpdatableProperty<T>	edit() Return an UpdatableProperty corresponding to this property.
List<Chronicle>	getChronicles(T value, int maxSize) Return a list of chronicles which have the given attribute value.
String	getName() Return the name of the property.
ValueType<T>	getValueType() Return the value type of the property.
boolean	isIndexed() Return true if the property has been defined as indexed.
T	scan(String value) Return an object of the underlying data type for this property converted from a textual value.
String	toString()
<S> Property<S>	typeCheck(Class<S> type) Cast the property to the type specified.
protected void	update() Refresh state.

Methods inherited from class ch.agent.crnickl.impl.DBObjectImpl

equals, getDatabase, getId, getSurrogate, hashCode, inConstruction, isValid

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface ch.agent.crnickl.api.DBObject

getDatabase, getId, getSurrogate, inConstruction, isValid

Constructor Detail

PropertyImpl

public PropertyImpl(String name,
                    ValueType<T> valueType,
                    boolean indexed,
                    Surrogate surrogate)

Construct a Property.

Parameters:

name - a string

valueType - a value type

indexed - true if the property is suitable for searching

surrogate - a surrogate

Method Detail

update

protected void update()

Refresh state.

getValueType

public ValueType<T> getValueType()

Description copied from interface: Property

Return the value type of the property.

Specified by:

getValueType in interface Property<T>

Returns:

the value type

edit

public UpdatableProperty<T> edit()

Description copied from interface: Property

Return an UpdatableProperty corresponding to this property. Successfully getting an Updatable object does not imply that updates can be successfully applied.

Specified by:

edit in interface Property<T>

Returns:

an updatable property corresponding to this property

isIndexed

public boolean isIndexed()

Description copied from interface: Property

Return true if the property has been defined as indexed. When a property is defined as indexed, it is meaningful to search for chronicles using Property.getChronicles(Object, int). To give an example, imagine a very large database where chronicles represent persons, with two attributes: country of residence and email address. You would not search for persons residing in the USA, would you? The size of the result would be enormous. On the other hand finding persons with a given email address would be fast.

Specified by:

isIndexed in interface Property<T>

Returns:

true if this is an indexed property

getName

public String getName()

Description copied from interface: Property

Return the name of the property.

Specified by:

getName in interface Property<T>

Returns:

the name of the property

scan

public T scan(String value)
       throws T2DBException

Description copied from interface: Property

Return an object of the underlying data type for this property converted from a textual value.

Specified by:

scan in interface Property<T>

Parameters:

value - a textual representation of the value

Returns:

the value of the underlying data type

Throws:

T2DBException

check

public void check(T value)
           throws T2DBException

Description copied from interface: Property

Check the value for conformity with the ValueType. An exception is thrown if the value does not conform. A typical cause of failure is that the value is not in the list of values allowed by a restricted value type.

Specified by:

check in interface Property<T>

Parameters:

value - a value to check

Throws:

T2DBException

getChronicles

public List<Chronicle> getChronicles(T value,
                                     int maxSize)
                              throws T2DBException

Description copied from interface: Property

Return a list of chronicles which have the given attribute value. A chronicle is included in the result only if the value is explicitly specified; default attribute values do not count. It is possible to limit the size of the result.

Specified by:

getChronicles in interface Property<T>

Parameters:

value - the value to match

maxSize - the maximum size of the result, 0 for no limit

Returns:

a list of chronicles

Throws:

T2DBException

typeCheck

public <S> Property<S> typeCheck(Class<S> type)
                          throws T2DBException

Description copied from interface: Property

Cast the property to the type specified. The method performs type checking at run time and allows to catch type errors in controlled fashion.

Specified by:

typeCheck in interface Property<T>

Parameters:

type - the underlying type required

Returns:

the property cast to the type specified

Throws:

T2DBException

toString

public String toString()

Overrides:

toString in class Object