br.com.arsmachina.dao

Interface ReadableDAO<T,K extends Serializable>

Type Parameters:

T - the entity class related to this DAO.

K - the type of the field that represents the entity class' primary key.

All Known Subinterfaces:

DAO<T,K>

public interface ReadableDAO<T,K extends Serializable>

Interface that defines a read-only, generic and generified Data Access Object (DAO) for a given entity class.

Author:

Thiago H. de Paula Figueiredo

Method Summary

Methods

Modifier and Type	Method and Description
long	countAll() Returns the total number of objects of this class.
List<T>	findAll() Returns the all instances of the related entity class.
List<T>	findAll(int firstResult, int maxResults, SortCriterion... sortingConstraints) Returns the all instances of the related entity class, but in a paginated fashion.
List<T>	findByExample(T example) Executes a query by example.
T	findById(K id) Returns the object with a given primary key value.
List<T>	findByIds(K... ids) Returns the objects with some given primary key values.
SortCriterion[]	getDefaultSortCriteria() Returns the default SortCriterions to be used to sort the objects lists returned by methods like findAll() and findAll(int, int, SortCriterion...) when no sort constraints are given.
T	reattach(T object) Reattaches an object to the persistence context, if there is one.
T	refresh(T object) Refreshes an object, getting the most recent version of its data from the object store.

Method Detail

countAll

long countAll()

Returns the total number of objects of this class.

Returns:

an long.

findById

T findById(K id)

Returns the object with a given primary key value.

Parameters:

id - a K.

Returns:

a T.

findByIds

List<T> findByIds(K... ids)

Returns the objects with some given primary key values.

Parameters:

ids - a K array.

Returns:

a List of T.

findAll

List<T> findAll()

Returns the all instances of the related entity class.

Returns:

a List of T.

findByExample

List<T> findByExample(T example)

Executes a query by example.

Parameters:

example - a T.

Returns:

a List of T.

refresh

T refresh(T object)

Refreshes an object, getting the most recent version of its data from the object store. It should return the same object passed as a parameter, overwritten with the most recent data, if possibile, but this isn't a requirement.

Parameters:

object - a T

Returns:

a T, which may or may not be the same object passed in the parameter.

reattach

T reattach(T object)

Reattaches an object to the persistence context, if there is one. The object store must not be changed. The attached object, which not necessarily is the one passed as a parameter, is returned.

Parameters:

object - a T.

Returns:

object a T.

findAll

List<T> findAll(int firstResult,
              int maxResults,
              SortCriterion... sortingConstraints)

Returns the all instances of the related entity class, but in a paginated fashion.

Parameters:

firstResult - an int with the index of the first object to be returned. The first object has index 0.

maxResults - an int with the maximum number of objects to be returned.

sortingConstraints - an SortCriterion array used to define how the returned list will be sorted.

Returns:

a List of T.

getDefaultSortCriteria

SortCriterion[] getDefaultSortCriteria()

Returns the default SortCriterions to be used to sort the objects lists returned by methods like findAll() and findAll(int, int, SortCriterion...) when no sort constraints are given.

Returns:

a SortCriterion array. It cannot be null.