程序包 org.hibernate.event.internal

类 MergeContext

java.lang.Object

org.hibernate.event.internal.MergeContext

所有已实现的接口:

Map

public class MergeContext
extends Object
implements Map

MergeContext is a Map implementation that is intended to be used by a merge event listener to keep track of each entity being merged and their corresponding managed result. Entities to be merged may to be added to the MergeContext before the merge operation has cascaded to that entity. "Merge entity" and "mergeEntity" method parameter refer to an entity that is (or will be) merged via Session.merge(Object mergeEntity). "Managed entity" and "managedEntity" method parameter refer to the managed entity that is the result of merging an entity. A merge entity can be transient, detached, or managed. If it is managed, then it must be the same as its associated entity result. If put(Object mergeEntity, Object managedEntity) is called, and this MergeContext already contains an entry with a different entity as the key, but with the same (managedEntity) value, this means that multiple entity representations for the same persistent entity are being merged. If this happens, EntityCopyObserver.entityCopyDetected( Object managedEntity, Object mergeEntity1, Object mergeEntity2, org.hibernate.event.spi.EventSource) will be called. It is up to that method to determine the property course of action for this situation. There are several restrictions.

• Methods that return collections (e.g., keySet(), values(), entrySet()) return an unmodifiable view of the collection;
• If managedEntity or put(Object mergeEntity, Object managedEntity, boolean isOperatedOn) is executed and this MergeMap already contains a cross-reference for mergeEntity, then managedEntity must be the same as what is already associated with mergeEntity in this MergeContext.
• If putAll(Map map) is executed, the previous restriction applies to each entry in the Map;
• The remove(Object) operation is not supported; The only way to remove data from a MergeContext is by calling clear();
• the Map returned by invertMap() will only contain the managed-to-merge entity cross-reference to its "newest" (most recently added) merge entity.

The following method is intended to be used by a merge event listener (and other classes) in the same package to add a merge entity and its corresponding managed entity to a MergeContext and indicate if the merge operation is being performed on the merge entity yet.

put(Object mergeEntity, Object managedEntity, boolean isOperatedOn)

The following method is intended to be used by a merge event listener (and other classes) in the same package to indicate whether the merge operation is being performed on a merge entity already in the MergeContext: setOperatedOn(Object mergeEntity, boolean isOperatedOn)

作者:

Gail Badner

嵌套类概要

从接口继承的嵌套类/接口 java.util.Map

Map.Entry<K extends Object,V extends Object>

构造器概要

构造器

构造器	说明
MergeContext(EventSource session, EntityCopyObserver entityCopyObserver)

方法概要

修饰符和类型	方法	说明
void	clear()	Clears the MergeContext.
boolean	containsKey(Object mergeEntity)	Returns true if this MergeContext contains a cross-reference for the specified merge entity to a managed entity result.
boolean	containsValue(Object managedEntity)	Returns true if this MergeContext contains a cross-reference from the specified managed entity to a merge entity.
Set	entrySet()	Returns an unmodifiable set view of the merge-to-managed entity cross-references contained in this MergeContext.
Object	get(Object mergeEntity)	Returns the managed entity associated with the specified merge Entity.
Map	invertMap()	Returns an unmodifiable map view of the managed-to-merge entity cross-references.
boolean	isEmpty()	Returns true if this MergeContext contains no merge-to-managed entity cross-references.
boolean	isOperatedOn(Object mergeEntity)	Returns true if the listener is performing the merge operation on the specified merge entity.
Set	keySet()	Returns an unmodifiable set view of the merge entities contained in this MergeContext
Object	put(Object mergeEntity, Object managedEntity)	Associates the specified merge entity with the specified managed entity result in this MergeContext.
Object	put(Object mergeEntity, Object managedEntity, boolean isOperatedOn)	Associates the specified merge entity with the specified managed entity in this MergeContext.
void	putAll(Map map)	Copies all of the mappings from the specified Map to this MergeContext.
Object	remove(Object mergeEntity)	The remove operation is not supported.
void	setOperatedOn(Object mergeEntity, boolean isOperatedOn)	Set flag to indicate if the listener is performing the merge operation on the specified merge entity.
int	size()	Returns the number of merge-to-managed entity cross-references in this MergeContext
Collection	values()	Returns an unmodifiable Set view of managed entities contained in this MergeContext.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

构造器详细资料

MergeContext

public MergeContext(EventSource session,
                    EntityCopyObserver entityCopyObserver)

方法详细资料

clear

public void clear()

Clears the MergeContext.

指定者:

clear 在接口中 Map

containsKey

public boolean containsKey(Object mergeEntity)

Returns true if this MergeContext contains a cross-reference for the specified merge entity to a managed entity result.

指定者:

containsKey 在接口中 Map

参数:

mergeEntity - must be non-null

返回:

true if this MergeContext contains a cross-reference for the specified merge entity

抛出:

NullPointerException - if mergeEntity is null

containsValue

public boolean containsValue(Object managedEntity)

Returns true if this MergeContext contains a cross-reference from the specified managed entity to a merge entity.

指定者:

containsValue 在接口中 Map

参数:

managedEntity - must be non-null

返回:

true if this MergeContext contains a cross-reference from the specified managed entity to a merge entity

抛出:

NullPointerException - if managedEntity is null

entrySet

public Set entrySet()

Returns an unmodifiable set view of the merge-to-managed entity cross-references contained in this MergeContext.

指定者:

entrySet 在接口中 Map

返回:

an unmodifiable set view of the merge-to-managed entity cross-references contained in this MergeContext

get

public Object get(Object mergeEntity)

Returns the managed entity associated with the specified merge Entity.

指定者:

get 在接口中 Map

参数:

mergeEntity - the merge entity; must be non-null

返回:

the managed entity associated with the specified merge Entity

抛出:

NullPointerException - if mergeEntity is null

isEmpty

public boolean isEmpty()

Returns true if this MergeContext contains no merge-to-managed entity cross-references.

指定者:

isEmpty 在接口中 Map

返回:

true if this MergeContext contains no merge-to-managed entity cross-references.

keySet

public Set keySet()

Returns an unmodifiable set view of the merge entities contained in this MergeContext

指定者:

keySet 在接口中 Map

返回:

an unmodifiable set view of the merge entities contained in this MergeContext

put

public Object put(Object mergeEntity,
                  Object managedEntity)

Associates the specified merge entity with the specified managed entity result in this MergeContext. If this MergeContext already contains a cross-reference for mergeEntity when this method is called, then managedEntity must be the same as what is already associated with mergeEntity.

This method assumes that the merge process is not yet operating on mergeEntity. Later when mergeEntity enters the merge process, setOperatedOn(Object, boolean) should be called.

指定者:

put 在接口中 Map

参数:

mergeEntity - the merge entity; must be non-null

managedEntity - the managed entity result; must be non-null

返回:

previous managed entity associated with specified merge entity, or null if there was no mapping for mergeEntity.

抛出:

NullPointerException - if mergeEntity or managedEntity is null

IllegalArgumentException - if managedEntity is not the same as the previous managed entity associated with merge entity

IllegalStateException - if internal cross-references are out of sync,

put

public Object put(Object mergeEntity,
                  Object managedEntity,
                  boolean isOperatedOn)

Associates the specified merge entity with the specified managed entity in this MergeContext. If this MergeContext already contains a cross-reference for mergeEntity when this method is called, then managedEntity must be the same as what is already associated with mergeEntity.

参数:

mergeEntity - the merge entity; must be non-null

managedEntity - the managed entity; must be non-null

isOperatedOn - indicates if the merge operation is performed on the mergeEntity.

返回:

previous managed entity associated with specified merge entity, or null if there was no mapping for mergeEntity.

抛出:

NullPointerException - if mergeEntity or managedEntity is null

IllegalArgumentException - if managedEntity is not the same as the previous managed entity associated with mergeEntity

IllegalStateException - if internal cross-references are out of sync,

putAll

public void putAll(Map map)

Copies all of the mappings from the specified Map to this MergeContext. The key and value for each entry in map is subject to the same restrictions as put(Object mergeEntity, Object managedEntity). This method assumes that the merge process is not yet operating on any merge entity

指定者:

putAll 在接口中 Map

参数:

map - keys and values must be non-null

抛出:

NullPointerException - if any key or value is null

IllegalArgumentException - if a key in map was already in this MergeContext but associated value in map is different from the previous value in this MergeContext.

IllegalStateException - if internal cross-references are out of sync,

remove

public Object remove(Object mergeEntity)

The remove operation is not supported.

指定者:

remove 在接口中 Map

参数:

mergeEntity - the merge entity.

抛出:

UnsupportedOperationException - if called.

size

public int size()

Returns the number of merge-to-managed entity cross-references in this MergeContext

指定者:

size 在接口中 Map

返回:

the number of merge-to-managed entity cross-references in this MergeContext

values

public Collection values()

Returns an unmodifiable Set view of managed entities contained in this MergeContext.

指定者:

values 在接口中 Map

返回:

an unmodifiable Set view of managed entities contained in this MergeContext

isOperatedOn

public boolean isOperatedOn(Object mergeEntity)

Returns true if the listener is performing the merge operation on the specified merge entity.

参数:

mergeEntity - the merge entity; must be non-null

返回:

true if the listener is performing the merge operation on the specified merge entity; false, if there is no mapping for mergeEntity.

抛出:

NullPointerException - if mergeEntity is null

setOperatedOn

public void setOperatedOn(Object mergeEntity,
                          boolean isOperatedOn)

Set flag to indicate if the listener is performing the merge operation on the specified merge entity.

参数:

mergeEntity - must be non-null and this MergeContext must contain a cross-reference for mergeEntity to a managed entity

抛出:

NullPointerException - if mergeEntity is null

IllegalStateException - if this MergeContext does not contain a a cross-reference for mergeEntity

invertMap

public Map invertMap()

Returns an unmodifiable map view of the managed-to-merge entity cross-references. The returned Map will contain a cross-reference from each managed entity to the most recently associated merge entity that was most recently put in the MergeContext.

返回:

an unmodifiable map view of the managed-to-merge entity cross-references.