uk.ac.ed.epcc.webapp.jdbc.expr

Interface Accessor<T,R>

Type Parameters:

T - type of return value

R - target object

All Superinterfaces:

Targetted<T>

All Known Subinterfaces:

FieldSQLExpression<T,X>, FieldValue<T,X>, SQLAccessor<T,R>

All Known Implementing Classes:

AbstractSelfSQLValue, BooleanFieldExpression, ConstExpression, DateFieldExpression, DurationAccessor, DurationFieldValue, FieldExpression, IndexedFieldValue, IntConvertAccessor, MillisecondAccessor, NumberFieldExpression, SelectAccessor, SelfSQLValue, StreamDataFieldExpression, StringConvertAccessor, StringFieldExpression, TimestampDateFieldExpression, TupleSelfSQLValue, TypeFilterProducerSQLValue, TypeProducerFieldValue

public interface Accessor<T,R>
extends Targetted<T>

Interface that encodes data access operation on a target object. These are usually defined with a DataObject as the target

An Accessor that can provide Filters based on the result type implements FilterProvider

An Accessor that also allows access via SQL implements SQLAccessor.

Unless an Accessor implements one or the other it won't be able to be used to filter results.

Method Summary

Modifier and Type	Method and Description
default boolean	canSet() does this Accessor support setting values.
T	getValue(R r) get the value from the target object
default void	setValue(R r, T value) Set value if supported otherwise throw a UnsupportedOperationException.

Methods inherited from interface uk.ac.ed.epcc.webapp.Targetted

getTarget

Method Detail

getValue

T getValue(R r)

get the value from the target object

Parameters:

r - target object

Returns:

value

canSet

default boolean canSet()

does this Accessor support setting values.

Returns:

setValue

default void setValue(R r,
                      T value)

Set value if supported otherwise throw a UnsupportedOperationException.

Parameters:

r -

value -