cz.datalite.service

Interface GenericService<T,ID extends Serializable>

All Known Implementing Classes:

GenericServiceImpl

public interface GenericService<T,ID extends Serializable>

Author:

Jiri Bubnik

Method Summary

Modifier and Type	Method and Description
T	attachPersistenceContext(T entity) Reattach the entity to the persistence context (without hitting the database).
Integer	count(cz.datalite.dao.DLSearch<T> search) Count all entities which accept criterias which is written in DLSearch.
void	delete(T entity) Delete the entity from database.
List<T>	findAll() Find all entities in this table
List<T>	findByExample(T exampleInstance) Find all entities like this example
List<T>	findByExample(T exampleInstance, String[] excludeProperty) Find all entities like this example
T	findById(ID id) Find entity with optimistic lock type.
T	findById(ID id, boolean lock) Find entity by Id using optimistic or pesimistic lock.
T	get(ID id) Find entity by Id.
T	get(ID id, String... path) Find entity by Id.
T	get(T entity) Get entity by instance.
T	get(T entity, String... associationPath) Get entity by instance.
void	save(T entity) Save or update the entity in database
List<T>	search(cz.datalite.dao.DLSearch<T> search) Find all entities which accept criterias which is written in DLSearch.
cz.datalite.dao.DLResponse<T>	searchAndCount(cz.datalite.dao.DLSearch<T> search) Returns a DLResponse object that includes both the list of results like search() and the total length like count().

Method Detail

get

T get(ID id)

Find entity by Id.

Parameters:

id - object identifier

Returns:

requested object or null

get

T get(ID id,
      String... path)

Find entity by Id.

Parameters:

id - object identifier

path - eager load associated entities on associationPath

Returns:

requested object or null

get

T get(T entity)

Get entity by instance. Typical usage is to get attached instance for detached entity.

This is convenience method - same result would be get(entity.getId())

Typical usage is to referesh current state in new request -> entity = get(entity); The method is null safe - if null, than nothing is done and null returned.

Parameters:

entity - object identifier or null

Returns:

same object or the attached instance. Null for null input.

get

T get(T entity,
      String... associationPath)

Get entity by instance. Typical usage is to get attached instance for detached entity.

This is convenience method - same result would be get(entity.getId())

Typical usage is to referesh current state in new request -> entity = get(entity); The method is null safe - if null, than nothing is done and null returned.

Parameters:

entity - object identifier or null

associationPath - eager load associated entities on associationPath

Returns:

same object or the attached instance. Null for null input.

findById

T findById(ID id,
           boolean lock)

Find entity by Id using optimistic or pesimistic lock. This method may return proxy to not existing object -> fail later in lazy loading.

Parameters:

id - entity identifir

lock - use pesimistic lock

Returns:

the persistent instance or proxy

findById

T findById(ID id)

Find entity with optimistic lock type. This method may return proxy to not existing object -> fail later in lazy loading.

Parameters:

id - entity identifier

Returns:

the persistent instance or proxy

findAll

List<T> findAll()

Find all entities in this table

Returns:

all exist entities

findByExample

List<T> findByExample(T exampleInstance)

Find all entities like this example

Parameters:

exampleInstance - example entity

Returns:

all exist similar entities

findByExample

List<T> findByExample(T exampleInstance,
                      String[] excludeProperty)

Find all entities like this example

Parameters:

exampleInstance - example entity

excludeProperty - properties to exclude

Returns:

all exist similar entities

search

List<T> search(cz.datalite.dao.DLSearch<T> search)

Find all entities which accept criterias which is written in DLSearch. Order of entities is defined in search object as well as projections and row count

Parameters:

search - object with search parameters

Returns:

corresponding entities

count

Integer count(cz.datalite.dao.DLSearch<T> search)

Count all entities which accept criterias which is written in DLSearch.

Parameters:

search - search object witch search parameters

Returns:

row count

searchAndCount

cz.datalite.dao.DLResponse<T> searchAndCount(cz.datalite.dao.DLSearch<T> search)

Returns a DLResponse object that includes both the list of results like search() and the total length like count().

Parameters:

search - search parameters

Returns:

result list with total length

save

void save(T entity)

Save or update the entity in database

Parameters:

entity - entity to store

delete

void delete(T entity)

Delete the entity from database.

Parameters:

entity - entity to delete.

attachPersistenceContext

T attachPersistenceContext(T entity)

Reattach the entity to the persistence context (without hitting the database).

Typical use is when you have entity instance from an old request (hence dettached) and you want it to allow lazy load subseqent entities. Without reattach you will get LazyInitializationException: could not initialize proxy - no Session.

If the another entity with the same ID is already in the persistence context, this method uses merge (and the new entity is returned). Otherwise this entity is only attached, no query executed.

Parameters:

entity - entity to reattach.

Returns:

the same object(rettached) or new entity representing same database object (if it was part of persistence context already)