EntityDataAccess (josef 3.2.5 API)

java.lang.Object
- org.josef.jpa.EntityDataAccess

```
@Status(stage=DEVELOPMENT,
        unitTests=PARTIAL)
 @Review(by="Kees Schotanus",
        at="2009-09-28")
public final class EntityDataAccess
extends Object
```
Utility class that provides data access for JPA/EJB 3 entities.
This class contains all the methods from EntityManager that directly deal with one or more JPA Entities. Use this class in combination with EntityManagerHelper for example to handle transactions.
Note: All create, update and delete actions are logged (whether they are successful or not).

Version:

1.0 $Revision: 6100 $

Author:

Kees Schotanus

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static <T> boolean`	`contains(T entity)` Determines whether the supplied entity belongs to the current persistence context.
`static <T> List<T>`	`executeNamedQuery(javax.persistence.EntityManager entityManager, String queryName, Map<String,Object> parameterNamesToValues, Class<T> type)` Executes a named query using the supplied entityManager.
`static <T> List<T>`	`executeNamedQuery(String queryName, Map<String,Object> queryParameters, Class<T> type)` Executes a named query.
`static <T> List<T>`	`findAll(Class<T> type)` Find all entities of the supplied class.
`static <T> List<T>`	`findAll(javax.persistence.EntityManager entityManager, Class<T> type)` Find all entities of the supplied class, using the supplied entityManager.
`static <T> List<T>`	`findByCriteria(Class<T> type, Searchable searchCriteria)` Finds entities of type <T> by criteria.
`static <T> List<T>`	`findByCriteria(javax.persistence.EntityManager entityManager, Class<T> type, Searchable searchCriteria)` Finds entities of type <T> by criteria using the supplied entityManager.
`static <T> T`	`findById(Class<T> type, Object primaryKey)` Finds a persisted entity by its id (primary key).
`static javax.persistence.EntityManager`	`getEntityManager()` Convenience method to get the EntityManagerHelper.
`static <T> T`	`getReference(Class<T> type, Object primaryKey)` Gets a reference to a persisted entity by its id (primary key).
`static void`	`lock(Object entity, javax.persistence.LockModeType lockMode)` Sets the supplied lockMode on the supplied entity.
`static <T> T`	`merge(T entity)` Merges the supplied entity with the persisted state of the supplied entity.
`static <T> T`	`persist(T entity)` Persists the supplied entity that previously should not have been persisted.
`static void`	`refresh(Object entity)` Refreshes the state of the supplied entity from the database.
`static <T> void`	`remove(Class<T> type, Object primaryKey)` Removes a previously persisted entity.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getEntityManager
```
public static javax.persistence.EntityManager getEntityManager()
```
    Convenience method to get the EntityManagerHelper.
    
    Returns:
    
    The EntityManager associated with the current thread.
  - persist
```
public static <T> T persist(T entity)
```
    Persists the supplied entity that previously should not have been persisted.
    After a successful persist the merge(Object) should be used.
    
    Type Parameters:
    
    T - The type of the entity to persist.
    
    Parameters:
    
    entity - The entity to persists.
    
    Returns:
    
    The persisted entity.
    
    Throws:
    
    NullPointerException - When the supplied entity is null.
    
    javax.persistence.PersistenceException - When the persist operation failed.
    
    See Also:
    
    EntityManager.persist(Object)
  - merge
```
public static <T> T merge(T entity)
```
    Merges the supplied entity with the persisted state of the supplied entity.
    
    Type Parameters:
    
    T - The type of the entity to merge.
    
    Parameters:
    
    entity - The entity to merge.
    
    Returns:
    
    A copy of the merged state of the supplied entity.
    
    Throws:
    
    NullPointerException - When the supplied entity is null.
    
    javax.persistence.PersistenceException - when the merge operation failed.
    
    See Also:
    
    EntityManager.merge(Object)
  - remove
```
public static <T> void remove(Class<T> type,
                              Object primaryKey)
```
    Removes a previously persisted entity.
    
    Type Parameters:
    
    T - The type of the entity to remove.
    
    Parameters:
    
    type - The class type of the entity to remove.
    
    primaryKey - The primary key of the entity to remove.
    
    Throws:
    
    NullPointerException - When the supplied primaryKey is null.
    
    javax.persistence.PersistenceException - when the remove operation failed.
    
    See Also:
    
    EntityManager.remove(Object)
  - contains
```
public static <T> boolean contains(T entity)
```
    Determines whether the supplied entity belongs to the current persistence context.
    
    Type Parameters:
    
    T - The type of entity to check.
    
    Parameters:
    
    entity - The entity to check.
    
    Returns:
    
    True when the supplied entity belongs to the current persistence context, otherwise false is returned.
    
    Throws:
    
    NullPointerException - When the supplied entity is null.
    
    See Also:
    
    EntityManager.contains(Object)
  - findById
```
public static <T> T findById(Class<T> type,
                             Object primaryKey)
```
    Finds a persisted entity by its id (primary key).
    
    Type Parameters:
    
    T - The type of the entity to find.
    
    Parameters:
    
    type - The class type of the entity to find.
    
    primaryKey - The primary key of the entity to find.
    
    Returns:
    
    The entity with the supplied primaryKey or null when no entity with the supplied primaryKey exists.
    
    Throws:
    
    NullPointerException - When either the supplied type or the supplied primaryKey is null.
    
    See Also:
    
    EntityManager.find(Class, Object)
  - findAll
```
public static <T> List<T> findAll(Class<T> type)
```
    Find all entities of the supplied class.
    
    Type Parameters:
    
    T - The type of the entities to find.
    
    Parameters:
    
    type - The class type of the entities to find.
    
    Returns:
    
    All elements of the supplied type.
    
    Throws:
    
    NullPointerException - When the supplied type is null.
  - findAll
```
public static <T> List<T> findAll(javax.persistence.EntityManager entityManager,
                                  Class<T> type)
```
    Find all entities of the supplied class, using the supplied entityManager.
    
    Type Parameters:
    
    T - The type of the entities to find.
    
    Parameters:
    
    entityManager - The entity manager to use.
    
    type - The class type of the entities to find.
    
    Returns:
    
    All elements of the supplied class.
    
    Throws:
    
    NullPointerException - When either the supplied entityManager or class is null.
  - findByCriteria
```
public static <T> List<T> findByCriteria(Class<T> type,
                                         Searchable searchCriteria)
```
    Finds entities of type <T> by criteria.
    
    Type Parameters:
    
    T - The type of the entities to find.
    
    Parameters:
    
    type - The class type of the entities to find.
    
    searchCriteria - The search criteria that are used to find the entities.
    
    Returns:
    
    All entities that adhere to the supplied searchCriteria.
    The returned List is possibly empty but never null.
    
    Throws:
    
    NullPointerException - When either the supplied theClass or searchCriteria is null.
  - findByCriteria
```
public static <T> List<T> findByCriteria(javax.persistence.EntityManager entityManager,
                                         Class<T> type,
                                         Searchable searchCriteria)
```
    Finds entities of type <T> by criteria using the supplied entityManager.
    
    Type Parameters:
    
    T - The type of the entities to find.
    
    Parameters:
    
    entityManager - The entity manager to use.
    
    type - The class type of the entities to find.
    
    searchCriteria - The search criteria that are used to find the entities.
    
    Returns:
    
    All entities that adhere to the supplied searchCriteria.
    The returned List is possibly empty but never null.
    
    Throws:
    
    NullPointerException - When either the supplied entityManager or theClass or searchCriteria is null.
  - executeNamedQuery
```
public static <T> List<T> executeNamedQuery(String queryName,
                                            Map<String,Object> queryParameters,
                                            Class<T> type)
```
    Executes a named query.
    
    Type Parameters:
    
    T - The type of the Persistable to return.
    
    Parameters:
    
    queryName - Name of the query.
    
    queryParameters - The query parameters.
    The named properties will be set on the query. Supply null when the named query does not accept properties.
    
    type - The class type of the entities to find.
    
    Returns:
    
    The result of executing the supplied namedQuery.
    
    Throws:
    
    NullPointerException - When either the supplied queryName or theClass is null.
    
    IllegalArgumentException - When the supplied queryName is empty.
  - executeNamedQuery
```
public static <T> List<T> executeNamedQuery(javax.persistence.EntityManager entityManager,
                                            String queryName,
                                            Map<String,Object> parameterNamesToValues,
                                            Class<T> type)
```
    Executes a named query using the supplied entityManager.
    
    Type Parameters:
    
    T - The type of the Persistable to return.
    
    Parameters:
    
    entityManager - The entity manager to use.
    
    queryName - Name of the query.
    
    parameterNamesToValues - The mapping of property names to property values.
    The named properties will be set on the query. Supply null when the named query does not accept properties.
    
    type - The class type of the entities to find.
    
    Returns:
    
    The result of executing the supplied namedQuery.
    
    Throws:
    
    NullPointerException - When either the supplied queryName or theClass is null.
    
    IllegalArgumentException - When the supplied queryName is empty.
  - getReference
```
public static <T> T getReference(Class<T> type,
                                 Object primaryKey)
```
    Gets a reference to a persisted entity by its id (primary key).
    This Entity may be lazily fetched and may throw an EntityNotFoundException upon first access.
    
    Type Parameters:
    
    T - The type of the entity to find.
    
    Parameters:
    
    type - The class type of the reference to get.
    
    primaryKey - The primary key the entity to find.
    
    Returns:
    
    The reference to an entity with the supplied primaryKey.
    
    Throws:
    
    javax.persistence.EntityNotFoundException - When the entity is not found.
    
    NullPointerException - When either the supplied type or the supplied primaryKey is null.
    
    See Also:
    
    EntityManager.getReference(Class, Object)
  - lock
```
public static void lock(Object entity,
                        javax.persistence.LockModeType lockMode)
```
    Sets the supplied lockMode on the supplied entity.
    
    Parameters:
    
    entity - The entity to lock.
    
    lockMode - The lock mode.
    
    Throws:
    
    IllegalArgumentException - When the supplied instance is a detached entity.
    
    IllegalStateException - When the EntityManager is closed.
    
    NullPointerException - When either the supplied entity or lockMode is null.
    
    javax.persistence.PersistenceException - When an unsupported lock call is made.
    
    javax.persistence.TransactionRequiredException - When no transaction exists.
  - refresh
```
public static void refresh(Object entity)
```
    Refreshes the state of the supplied entity from the database.
    
    Parameters:
    
    entity - The entity to refresh.
    
    Throws:
    
    IllegalArgumentException - When the supplied entity is not managed.
    
    IllegalStateException - When the EntityManager is closed.
    
    NullPointerException - When the supplied entity is null.
    
    javax.persistence.TransactionRequiredException - When no transaction exists.
    
    javax.persistence.EntityNotFoundException - When the supplied entity does no longer exists in the database.
    
    See Also:
    
    EntityManager.refresh(Object)

Class EntityDataAccess

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getEntityManager

persist

merge

remove

contains

findById

findAll

findAll

findByCriteria

findByCriteria

executeNamedQuery

executeNamedQuery

getReference

lock

refresh