Package org.jboss.ejb.client

Class Attachable

java.lang.Object

org.jboss.ejb.client.Attachable

Direct Known Subclasses:

AbstractInvocationContext, EJBClientContext, EJBReceiver

public abstract class Attachable
extends Object

An object which may have attachments. Even if the object is serializable, its attachment map is not and will always deserialize empty.

Author:

David M. Lloyd

Method Summary

Modifier and Type	Method	Description
<T> T	getAttachment(AttachmentKey<T> key)	Get an attachment from this object.
Map<AttachmentKey<?>,?>	getAttachments()	Returns the attachments applicable for this Attachable.
<T> T	putAttachment(AttachmentKey<T> key, T value)	Set an attachment on this object.
<T> T	putAttachmentIfAbsent(AttachmentKey<T> key, T value)	Set an attachment on this object if an existing attachment does not already exist.
<T> T	removeAttachment(AttachmentKey<T> key)	Remove and return an attachment value.
<T> boolean	removeAttachment(AttachmentKey<T> key, T value)	Remove an attachment if it has a certain value.
<T> T	replaceAttachment(AttachmentKey<T> key, T value)	Replace an attachment on this object if an existing attachment exists.
<T> boolean	replaceAttachment(AttachmentKey<T> key, T oldValue, T newValue)	Replace an attachment on this object if an existing attachment exists with a certain value.

Methods inherited from class java.lang.Object

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

Method Detail

getAttachment

public <T> T getAttachment(AttachmentKey<T> key)

Get an attachment from this object.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

Returns:

the attachment value

getAttachments

public Map<AttachmentKey<?>,?> getAttachments()

Returns the attachments applicable for this Attachable. The returned Map is an unmodifiable Map. If there are no attachments for this Attachable then this method returns an empty Map

Returns:

a read-only copy of the attachments map

putAttachment

public <T> T putAttachment(AttachmentKey<T> key,
                           T value)

Set an attachment on this object.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

value - the attachment's new value (may not be null)

Returns:

the previous attachment value, or null if there was none

putAttachmentIfAbsent

public <T> T putAttachmentIfAbsent(AttachmentKey<T> key,
                                   T value)

Set an attachment on this object if an existing attachment does not already exist.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

value - the attachment's new value (may not be null)

Returns:

the previous attachment value, or null if there was none

replaceAttachment

public <T> T replaceAttachment(AttachmentKey<T> key,
                               T value)

Replace an attachment on this object if an existing attachment exists.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

value - the attachment's new value (may not be null)

Returns:

the previous attachment value, or null if there was none

replaceAttachment

public <T> boolean replaceAttachment(AttachmentKey<T> key,
                                     T oldValue,
                                     T newValue)

Replace an attachment on this object if an existing attachment exists with a certain value.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

oldValue - the attachment's expected value (may not be null)

newValue - the attachment's new value (may not be null)

Returns:

true if the old value matched and the value was replaced; false otherwise

removeAttachment

public <T> T removeAttachment(AttachmentKey<T> key)

Remove and return an attachment value.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

Returns:

the previous value of the attachment, or null if there was none

removeAttachment

public <T> boolean removeAttachment(AttachmentKey<T> key,
                                    T value)

Remove an attachment if it has a certain value.

Type Parameters:

T - the attachment type

Parameters:

key - the attachment key

value - the attachment's expected value (may not be null)

Returns:

true if the value was removed, false if there was no attachment