Package org.hibernate.reactive.stage

Interface Stage.Session

All Superinterfaces:
Stage.Closeable, Stage.QueryProducer
Enclosing interface:
Stage
public static interface Stage.Session extends Stage.QueryProducer, Stage.Closeable
A non-blocking counterpart to the Hibernate Session interface, allowing a reactive style of interaction with the database.

The semantics of operations on this interface are identical to the semantics of the similarly-named operations of Session, except that the operations are performed asynchronously, returning a CompletionStage without blocking the calling thread.

Entities associated with an Session do not support transparent lazy association fetching. Instead, fetch(Object) should be used to explicitly request asynchronous fetching of an association, or the association should be fetched eagerly when the entity is first retrieved, for example, by:

See Also:

  • Method Details

    • find

      <T> CompletionStage<T> find(Class<T> entityClass, Object id)
      Asynchronously return the persistent instance of the given entity class with the given identifier, or null if there is no such persistent instance. If the instance is already associated with the session, return the associated instance. This method never returns an uninitialized instance. 
       session.find(Book.class, id).thenAccept(book -> print(book.getTitle()));
      Parameters:
      entityClass - The entity type
      id - an identifier
      Returns:
      a persistent instance or null via a CompletionStage
      See Also:
      • EntityManager.find(Class, Object)

    • find

      <T> CompletionStage<T> find(Class<T> entityClass, Object id, LockMode lockMode)
      Asynchronously return the persistent instance of the given entity class with the given identifier, requesting the given LockMode.
      Parameters:
      entityClass - The entity type
      id - an identifier
      lockMode - the requested LockMode
      Returns:
      a persistent instance or null via a CompletionStage
      See Also:

    • find

      default <T> CompletionStage<T> find(Class<T> entityClass, Object id, jakarta.persistence.LockModeType lockModeType)
      Asynchronously return the persistent instance of the given entity class with the given identifier, requesting the given LockModeType.
      Parameters:
      entityClass - The entity type
      id - an identifier
      lockModeType - the requested LockModeType
      Returns:
      a persistent instance or null via a CompletionStage
      See Also:

    • find

      <T> CompletionStage<T> find(jakarta.persistence.EntityGraph<T> entityGraph, Object id)
      Asynchronously return the persistent instance with the given identifier of an entity class, using the given EntityGraph as a fetch plan.
      Parameters:
      entityGraph - an EntityGraph specifying the entity and associations to be fetched
      id - an identifier
      See Also:

    • find

      <T> CompletionStage<List<T>> find(Class<T> entityClass, Object... ids)
      Asynchronously return the persistent instances of the given entity class with the given identifiers, or null if there is no such persistent instance.
      Parameters:
      entityClass - The entity type
      ids - the identifiers
      Returns:
      a list of persistent instances and nulls via a CompletionStage

    • find

      @Incubating <T> CompletionStage<T> find(Class<T> entityClass, Identifier<T> naturalId)
      Asynchronously return the persistent instance of the given entity class with the given natural identifiers, or null if there is no such persistent instance.
      Parameters:
      entityClass - The entity type
      naturalId - the natural identifier
      Returns:
      a persistent instance or null via a CompletionStage

    • getReference

      <T> T getReference(Class<T> entityClass, Object id)
      Return the persistent instance of the given entity class with the given identifier, assuming that the instance exists. This method never results in access to the underlying data store, and thus might return a proxy that must be initialized explicitly using fetch(Object).

      You should not use this method to determine if an instance exists (use find(java.lang.Class<T>, java.lang.Object) instead). Use this only to retrieve an instance which you safely assume exists, where non-existence would be an actual error.

      Parameters:
      entityClass - a persistent class
      id - a valid identifier of an existing persistent instance of the class
      Returns:
      the persistent instance or proxy
      See Also:
      • EntityManager.getReference(Class, Object)

    • getReference

      <T> T getReference(T entity)
      Return the persistent instance with the same identity as the given instance, which might be detached, assuming that the instance is still persistent in the database. This method never results in access to the underlying data store, and thus might return a proxy that must be initialized explicitly using fetch(Object).
      Parameters:
      entity - a detached persistent instance
      Returns:
      the persistent instance or proxy

    • persist

      CompletionStage<Void> persist(Object entity)
      Asynchronously persist the given transient instance, first assigning a generated identifier. (Or using the current value of the identifier property if the entity has assigned identifiers.)

      This operation cascades to associated instances if the association is mapped with CascadeType.PERSIST. 

       session.persist(newBook).thenAccept(v -> session.flush());
      Parameters:
      entity - a transient instance of a persistent class
      See Also:
      • EntityManager.persist(Object)

    • persist

      CompletionStage<Void> persist(String entityName, Object object)
      Make a transient instance persistent and mark it for later insertion in the database. This operation cascades to associated instances if the association is mapped with CascadeType.PERSIST.

      For entities with a generated id, persist() ultimately results in generation of an identifier for the given instance. But this may happen asynchronously, when the session is flushed, depending on the identifier generation strategy.

      Parameters:
      entityName - the entity name
      object - a transient instance to be made persistent
      See Also:

    • persist

      CompletionStage<Void> persist(Object... entities)
      Persist multiple transient entity instances at once.
      See Also:

    • remove

      CompletionStage<Void> remove(Object entity)
      Asynchronously remove a persistent instance from the datastore. The argument may be an instance associated with the receiving session or a transient instance with an identifier associated with existing persistent state.

      This operation cascades to associated instances if the association is mapped with CascadeType.REMOVE. 

       session.delete(book).thenAccept(v -> session.flush());
      Parameters:
      entity - the managed persistent instance to be removed
      Throws:
      IllegalArgumentException - if the given instance is not managed
      See Also:
      • EntityManager.remove(Object)

    • remove

      CompletionStage<Void> remove(Object... entities)
      Remove multiple entity instances at once.
      See Also:

    • merge

      <T> CompletionStage<T> merge(T entity)
      Copy the state of the given object onto the persistent instance with the same identifier. If there is no such persistent instance currently associated with the session, it will be loaded. Return the persistent instance. Or, if the given instance is transient, save a copy of it and return the copy as a newly persistent instance. The given instance does not become associated with the session.

      This operation cascades to associated instances if the association is mapped with CascadeType.MERGE.

      Parameters:
      entity - a detached instance with state to be copied
      Returns:
      an updated persistent instance
      See Also:
      • EntityManager.merge(Object)

    • merge

      CompletionStage<Void> merge(Object... entities)
      Merge multiple entity instances at once.
      See Also:

    • refresh

      CompletionStage<Void> refresh(Object entity)
      Re-read the state of the given instance from the underlying database. It is inadvisable to use this to implement long-running sessions that span many business tasks. This method is, however, useful in certain special circumstances, for example:
      • where a database trigger alters the object state after insert or update, or
      • after executing direct native SQL in the same session.
      Parameters:
      entity - a managed persistent instance
      Throws:
      IllegalArgumentException - if the given instance is not managed
      See Also:
      • EntityManager.refresh(Object)

    • refresh

      CompletionStage<Void> refresh(Object entity, LockMode lockMode)
      Re-read the state of the given instance from the underlying database, requesting the given LockMode.
      Parameters:
      entity - a managed persistent entity instance
      lockMode - the requested lock mode
      See Also:

    • refresh

      default CompletionStage<Void> refresh(Object entity, jakarta.persistence.LockModeType lockModeType)
      Re-read the state of the given instance from the underlying database, requesting the given LockModeType.
      Parameters:
      entity - a managed persistent entity instance
      lockModeType - the requested lock mode
      See Also:

    • refresh

      CompletionStage<Void> refresh(Object... entities)
      Refresh multiple entity instances at once.
      See Also:

    • lock

      CompletionStage<Void> lock(Object entity, LockMode lockMode)
      Obtain the specified lock level upon the given object. For example, this operation may be used to: This operation cascades to associated instances if the association is mapped with CascadeType.LOCK.
      Parameters:
      entity - a managed persistent instance
      lockMode - the lock level
      Throws:
      IllegalArgumentException - if the given instance is not managed

    • lock

      default CompletionStage<Void> lock(Object entity, jakarta.persistence.LockModeType lockModeType)
      Obtain the specified lock level upon the given object. For example, this operation may be used to:
      • perform a version check with LockModeType.PESSIMISTIC_READ,
      • upgrade to a pessimistic lock with LockModeType.PESSIMISTIC_WRITE,
      • force a version increment with LockModeType.PESSIMISTIC_FORCE_INCREMENT,
      • schedule a version check just before the end of the transaction with LockModeType.OPTIMISTIC, or
      • schedule a version increment just before the end of the transaction with LockModeType.OPTIMISTIC_FORCE_INCREMENT.
      This operation cascades to associated instances if the association is mapped with CascadeType.LOCK.
      Parameters:
      entity - a managed persistent instance
      lockModeType - the lock level
      Throws:
      IllegalArgumentException - if the given instance is not managed

    • flush

      CompletionStage<Void> flush()
      Force this session to flush asynchronously. Must be called at the end of a unit of work, before committing the transaction and closing the session. Flushing is the process of synchronizing the underlying persistent store with state held in memory. 
       session.flush().thenAccept(v -> print("done saving changes"));
      See Also:
      • EntityManager.flush()

    • fetch

      <T> CompletionStage<T> fetch(T association)
      Asynchronously fetch an association configured for lazy loading. 

       session.fetch(author.getBook()).thenAccept(book -> print(book.getTitle()))

      This operation may be even be used to initialize a reference returned by getReference(Class, Object). 

       session.fetch(session.getReference(Author.class, authorId))

      Parameters:
      association - a lazy-loaded association, or a proxy
      Returns:
      the fetched association, via a CompletionStage
      See Also:

    • fetch

      <E, T> CompletionStage<T> fetch(E entity, jakarta.persistence.metamodel.Attribute<E,T> field)
      Fetch a lazy property of the given entity, identified by a JPA attribute metamodel. Note that this feature is only supported in conjunction with the Hibernate bytecode enhancer. 
       session.fetch(book, Book_.isbn).thenAccept(isbn -> print(isbn))

    • unproxy

      <T> CompletionStage<T> unproxy(T association)
      Asynchronously fetch an association that's configured for lazy loading, and unwrap the underlying entity implementation from any proxy. 
       session.unproxy(author.getBook()).thenAccept(book -> print(book.getTitle()));
      Parameters:
      association - a lazy-loaded association
      Returns:
      the fetched association, via a CompletionStage
      See Also:

    • getLockMode

      LockMode getLockMode(Object entity)
      Determine the current lock mode of the given entity.

    • contains

      boolean contains(Object entity)
      Determine if the given instance belongs to this persistence context.

    • setFlushMode

      Stage.Session setFlushMode(FlushMode flushMode)
      Set the flush mode for this session.

      The flush mode determines the points at which the session is flushed. Flushing is the process of synchronizing the underlying persistent store with persistable state held in memory.

      For a logically "read only" session, it is reasonable to set the session's flush mode to FlushMode.MANUAL at the start of the session (in order to achieve some extra performance).

      Parameters:
      flushMode - the new flush mode

    • setFlushMode

      default Stage.Session setFlushMode(jakarta.persistence.FlushModeType flushModeType)
      Set the flush mode for this session.

      The flush mode determines the points at which the session is flushed. Flushing is the process of synchronizing the underlying persistent store with persistable state held in memory.

      Parameters:
      flushModeType - the new flush mode

    • getFlushMode

      FlushMode getFlushMode()
      Get the current flush mode for this session.
      Returns:
      the flush mode

    • detach

      Stage.Session detach(Object entity)
      Remove this instance from the session cache. Changes to the instance will not be synchronized with the database.

      This operation cascades to associated instances if the association is mapped with CascadeType.DETACH.

      Parameters:
      entity - The entity to evict
      Throws:
      NullPointerException - if the passed object is null
      IllegalArgumentException - if the passed object is not defined as an entity
      See Also:
      • EntityManager.detach(Object)

    • clear

      Stage.Session clear()
      Completely clear the session. Detach all persistent instances and cancel all pending insertions, updates and deletions.
      See Also:
      • EntityManager.clear()

    • enableFetchProfile

      Stage.Session enableFetchProfile(String name)
      Enable a particular fetch profile on this session, or do nothing if requested fetch profile is already enabled.
      Parameters:
      name - The name of the fetch profile to be enabled.
      Throws:
      UnknownProfileException - Indicates that the given name does not match any known profile names
      See Also:

    • disableFetchProfile

      Stage.Session disableFetchProfile(String name)
      Disable a particular fetch profile on this session, or do nothing if the requested fetch profile is not enabled.
      Parameters:
      name - The name of the fetch profile to be disabled.
      Throws:
      UnknownProfileException - Indicates that the given name does not match any known profile names
      See Also:

    • isFetchProfileEnabled

      boolean isFetchProfileEnabled(String name)
      Determine if the fetch profile with the given name is enabled for this session.
      Parameters:
      name - The name of the profile to be checked.
      Returns:
      True if fetch profile is enabled; false if not.
      Throws:
      UnknownProfileException - Indicates that the given name does not match any known profile names
      See Also:

    • setDefaultReadOnly

      Stage.Session setDefaultReadOnly(boolean readOnly)
      Change the default for entities and proxies loaded into this session from modifiable to read-only mode, or from modifiable to read-only mode.

      Read-only entities are not dirty-checked and snapshots of persistent state are not maintained. Read-only entities can be modified, but changes are not persisted.

      See Also:

    • isDefaultReadOnly

      boolean isDefaultReadOnly()
      Returns:
      the default read-only mode for entities and proxies loaded in this session

    • setReadOnly

      Stage.Session setReadOnly(Object entityOrProxy, boolean readOnly)
      Set an unmodified persistent object to read-only mode, or a read-only object to modifiable mode. In read-only mode, no snapshot is maintained, the instance is never dirty checked, and changes are not persisted.
      See Also:

    • isReadOnly

      boolean isReadOnly(Object entityOrProxy)
      Is the specified entity or proxy read-only?
      See Also:

    • setCacheMode

      Stage.Session setCacheMode(CacheMode cacheMode)
      Set the cache mode for this session.

      The cache mode determines the manner in which this session interacts with the second level cache.

      Parameters:
      cacheMode - The new cache mode.

    • setCacheStoreMode

      default Stage.Session setCacheStoreMode(jakarta.persistence.CacheStoreMode cacheStoreMode)
      Set the CacheStoreMode for this session.
      Parameters:
      cacheStoreMode - The new cache store mode.

    • setCacheRetrieveMode

      default Stage.Session setCacheRetrieveMode(jakarta.persistence.CacheRetrieveMode cacheRetrieveMode)
      Set the CacheRetrieveMode for this session.
      Parameters:
      cacheRetrieveMode - The new cache retrieve mode.

    • getCacheMode

      CacheMode getCacheMode()
      Get the current cache mode.
      Returns:
      The current cache mode.

    • setBatchSize

      Stage.Session setBatchSize(Integer batchSize)
      Set the session-level batch size, overriding the batch size set by the configuration property hibernate.jdbc.batch_size.

    • getBatchSize

      Integer getBatchSize()
      The session-level batch size, or null if it has not been overridden.

    • getFetchBatchSize

      int getFetchBatchSize()
      Get the maximum batch size for batch fetching associations by id in this session.
      Since:
      2.1

    • setFetchBatchSize

      Stage.Session setFetchBatchSize(int batchSize)
      Set the maximum batch size for batch fetching associations by id in this session. Override the default controlled by the configuration property hibernate.default_batch_fetch_size.

      • If batchSize>1, then batch fetching is enabled.
      • If batchSize<0, the batch size is inherited from the factory-level setting.
      • Otherwise, batch fetching is disabled.
      Parameters:
      batchSize - the maximum batch size for batch fetching
      Since:
      2.1

    • isSubselectFetchingEnabled

      boolean isSubselectFetchingEnabled()
      Determine if subselect fetching is enabled in this session.
      Returns:
      true if subselect fetching is enabled
      Since:
      2.1

    • setSubselectFetchingEnabled

      Stage.Session setSubselectFetchingEnabled(boolean enabled)
      Enable or disable subselect fetching in this session. Override the default controlled by the configuration property hibernate.use_subselect_fetch.
      Parameters:
      enabled - true to enable subselect fetching
      Since:
      2.1

    • enableFilter

      Filter enableFilter(String filterName)
      Enable the named filter for this session.
      Parameters:
      filterName - The name of the filter to be enabled.
      Returns:
      The Filter instance representing the enabled filter.

    • disableFilter

      void disableFilter(String filterName)
      Disable the named filter for this session.
      Parameters:
      filterName - The name of the filter to be disabled.

    • getEnabledFilter

      Filter getEnabledFilter(String filterName)
      Retrieve a currently enabled filter by name.
      Parameters:
      filterName - The name of the filter to be retrieved.
      Returns:
      The Filter instance representing the enabled filter.

    • withTransaction

      <T> CompletionStage<T> withTransaction(Function<Stage.Transaction,CompletionStage<T>> work)
      Performs the given work within the scope of a database transaction, automatically flushing the session. The transaction will be rolled back if the work completes with an uncaught exception, or if Stage.Transaction.markForRollback() is called.

      The resulting Stage.Transaction object may also be obtained via currentTransaction().

    • If there is already a transaction associated with this session, the work is executed in the context of the existing transaction, and no new transaction is initiated.
    • If there is no transaction associated with this session, a new transaction is started, and the work is executed in the context of the new transaction.
      • Parameters:
      work - a function which accepts Stage.Transaction and returns the result of the work as a CompletionStage.
      See Also:

    • currentTransaction

      Stage.Transaction currentTransaction()
      Obtain the transaction currently associated with this session, if any.
      Returns:
      the Stage.Transaction, or null if no transaction was started using withTransaction(Function).
      See Also:

    • isOpen

      boolean isOpen()
      Returns:
      false if Stage.Closeable.close() has been called

    • getFactory

      Stage.SessionFactory getFactory()
      The Stage.SessionFactory which created this session.