org.wisdom.api.model.Crud Maven / Gradle / Ivy
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* Copyright (C) 2013 - 2014 Wisdom Framework
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* Licensed under the Apache License, Version 2.0 (the "License");
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package org.wisdom.api.model;
import java.io.Serializable;
import java.util.concurrent.Callable;
/**
* A service to let components access entities stored in a repository (i.e. persistence layer).
* This service manages only one type of entity (i.e. class). For example, the entity Task would have its own
* CrudService while the entity User would have another one.
*
* The CRUD Service is independent of the persistent layer used. If you need to access low-level API,
* use the getRepository method.
*
* Providers must register the 'entity.class' and 'entity.classname' properties in their service registration. The
* first property register the class object, while the second only its name.
*
* @param the type of the entity
* @param the type of the ids
*/
public interface Crud {
/**
* The service property that must be published to indicate the entity class.
*/
public static final String ENTITY_CLASS_PROPERTY = "entity.class";
/**
* The service property that must be published to indicate the entity qualified class name.
*/
public static final String ENTITY_CLASSNAME_PROPERTY = "entity.classname";
/**
* Gets the class of the represented entity.
* @return the repository managing this entity.
*/
Class getEntityClass();
/**
* Gets the class of the Id used by the persistent layer.
* @return the type of the id.
*/
Class getIdClass();
/**
* Deletes the given entity instance. The instance is removed from the persistent layer.
* @param t the instance
* @return the entity instance, may be the same as the parameter t but can also be different
*/
T delete(T t);
/**
* Deletes the given entity instance (specified by its id). The instance is removed from the persistent layer.
* @param id the id
* @return the entity instance, may be the same as the parameter t but can also be different
*/
void delete(I id);
/**
* Deletes the given entity instances. The instances are removed from the persistent layer.
* @param entities the entities to remove from the persistent layer
* @return the set of entity instances
*/
Iterable delete(Iterable entities);
/**
* Saves a given entity. Use the returned instance for further operations as the operation might have
* changed the entity instance completely.
*
* This method is used to save a new entity or to update it.
* @param t the instance to save
* @return the saved entity
*/
T save(T t);
/**
* Saves all given entities. Use the returned instances for further operations as the operation might have
* changed the entity instances completely.
* @param entities the entities to save, must not contains {@literal null} values
* @return the saved entities
*/
Iterable save(Iterable entities);
/**
* Retrieves an entity by its id.
* @param id the id, must not be null
* @return the entity instance, {@literal null} if there are no entities matching the given id.
*/
T findOne(I id);
/**
* Retrieves the entity matching the given filter. If several entities matches, the first is returned.
* @param filter the filter
* @return the first matching instance, {@literal null} if none
*/
T findOne(EntityFilter filter);
/**
* Checks whether an entity instance with the given id exists, i.e. has been saved and is persisted.
* @param id the id, must not be null
* @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
*/
boolean exists(I id);
/**
* Returns all instances of the entity.
* @return the instances, empty if none.
*/
Iterable findAll();
/**
* Returns all instances of the type with the given IDs.
* @param ids the ids.
* @return the instances, empty if none.
*/
Iterable findAll(Iterable ids);
/**
* Retrieves the entities matching the given filter.
* Be aware that the implementation may load all stored entities in memory to retrieve the right set of entities.
* @param filter the filter
* @return the matching instances, empty if none.
*/
Iterable findAll(EntityFilter filter);
/**
* Gets the number of stored instances.
* @return the number of stored instances, 0 if none.
*/
long count();
/**
* Gets the repository storing the instances of this entity.
* @return the repository object, may be {@literal null} if there are no repository.
*/
Repository getRepository();
/**
* Executes the given runnable in a transaction. If the block throws an exception, the transaction is rolled back.
* This method may not be supported by all persistent technologies, as they are not necessary supporting
* transactions. In that case, this method throw a {@link java.lang.UnsupportedOperationException}.
* @param runnable the runnable to execute in a transaction
* @throws java.lang.UnsupportedOperationException if transactions are not supported.
*/
void executeTransactionalBlock(Runnable runnable);
/**
* Executes the given runnable in a transaction. If the block throws an exception, the transaction is rolled back.
* This method may not be supported by all persistent technologies, as they are not necessary supporting
* transactions. In that case, this method throw a {@link java.lang.UnsupportedOperationException}.
* @param callable the block to execute in a transaction
* @return A the result
* @throws java.lang.UnsupportedOperationException if transactions are not supported.
*/
A executeTransactionalBlock(Callable callable);
}