12  

Hibernate does not expose its internals to the public, so you won't find what you are searching for in the public API. However you can find your answer in the implementation classes of the Hibernate interfaces: This method (taken from http://code.google.com/p/bo2/source/browse/trunk/Bo2ImplHibernate/main/gr/interamerican/bo2/impl/open/hibernate/HibernateBo2Utils.java) will tell if an object exists in the session:

Hibernate不会向公众公开其内部，因此您将无法在公共API中找到您要搜索的内容。但是，您可以在Hibernate接口的实现类中找到答案：此方法（摘自http://code.google.com/p/bo2/source/browse/trunk/Bo2ImplHibernate/main/gr/interamerican/bo2/ impl / open / hibernate / HibernateBo2Utils.java）将告诉会话中是否存在对象：

public static Object getFromSession
        (Serializable identifier, Class<?> clazz, Session s) {              
    String entityName = clazz.getName();
    if(identifier == null) {
       return null;
    }      
    SessionImplementor sessionImpl = (SessionImplementor) s;
    EntityPersister entityPersister = sessionImpl.getFactory().getEntityPersister(entityName);
    PersistenceContext persistenceContext = sessionImpl.getPersistenceContext();
    EntityKey entityKey = new EntityKey(identifier, entityPersister, EntityMode.POJO);
    Object entity = persistenceContext.getEntity(entityKey);
    return entity;
    }

If you drill down a little more, you will see that the only implementation of PersistenceContext is org.hibernate.engine.StatefulPersistenceContext. This class has the following collections:

如果向下钻取一点，您将看到PersistenceContext的唯一实现是org.hibernate.engine.StatefulPersistenceContext。该类具有以下集合：

// Loaded entity instances, by EntityKey
private Map entitiesByKey;

// Loaded entity instances, by EntityUniqueKey
private Map entitiesByUniqueKey;

// Identity map of EntityEntry instances, by the entity instance
private Map entityEntries;

// Entity proxies, by EntityKey
private Map proxiesByKey;

// Snapshots of current database state for entities
// that have *not* been loaded
private Map entitySnapshotsByKey;

// Identity map of array holder ArrayHolder instances, by the array instance
private Map arrayHolders;

// Identity map of CollectionEntry instances, by the collection wrapper
private Map collectionEntries;

// Collection wrappers, by the CollectionKey
private Map collectionsByKey; //key=CollectionKey, value=PersistentCollection

// Set of EntityKeys of deleted objects
private HashSet nullifiableEntityKeys;

// properties that we have tried to load, and not found in the database
private HashSet nullAssociations;

// A list of collection wrappers that were instantiating during result set
// processing, that we will need to initialize at the end of the query
private List nonlazyCollections;

// A container for collections we load up when the owning entity is not
// yet loaded ... for now, this is purely transient!
private Map unownedCollections;

// Parent entities cache by their child for cascading
// May be empty or not contains all relation 
private Map parentsByChild;

So, what you need to do is cast the PersistenceContext to a StatefulPersistenceContext, then use reflection to get the private collection that you want and then iterate on it.

因此，您需要做的是将PersistenceContext转换为StatefulPersistenceContext，然后使用反射来获取所需的私有集合，然后对其进行迭代。

I strongly suggest you do that only on debugging code. This is not public API and it could brake by newer releases of Hibernate.

我强烈建议你只在调试代码时这样做。这不是公共API，它可以通过更新版本的Hibernate来制动。

9  

Found @nakosspy post very useful. Inspired by his post, I added this very simple utility method that outputs the contents of Hibernate Session.

发现@nakosspy帖非常有用。受他的帖子的启发，我添加了这个非常简单的实用方法，它输出Hibernate Session的内容。

As nakosspy said this is ONLY for debugging purposes as it is a HACK.

正如nakosspy所说，这仅用于调试目的，因为它是一个HACK。

    public static void dumpHibernateSession(Session s) {
    try {
        SessionImplementor sessionImpl = (SessionImplementor) s;
        PersistenceContext persistenceContext = sessionImpl.getPersistenceContext();
        Field entityEntriesField = StatefulPersistenceContext.class.getDeclaredField("entityEntries");
        entityEntriesField.setAccessible(true);
        IdentityMap map = (IdentityMap) entityEntriesField.get(persistenceContext);
        log.info(map);
    } catch (Exception e)
    {
        log.error(e);
    }

}