org.springframework.aop.target.dynamic

Class AbstractRefreshableTargetSource

java.lang.Object

org.springframework.aop.target.dynamic.AbstractRefreshableTargetSource

All Implemented Interfaces:

Refreshable, TargetClassAware, TargetSource

Direct Known Subclasses:

BeanFactoryRefreshableTargetSource

public abstract class AbstractRefreshableTargetSource
extends java.lang.Object
implements TargetSource, Refreshable

Abstract TargetSource implementation that wraps a refreshable target object. Subclasses can determine whether a refresh is required, and need to provide fresh target objects.

Implements the Refreshable interface in order to allow for explicit control over the refresh status.

Since:

2.0

Author:

Rod Johnson, Rob Harrop, Juergen Hoeller

See Also:

requiresRefresh(), freshTarget()

Field Summary

Fields

Modifier and Type	Field and Description
protected Log	logger Logger available to subclasses
protected java.lang.Object	targetObject

Constructor Summary

Constructors

Constructor and Description
AbstractRefreshableTargetSource()

Method Summary

Modifier and Type	Method and Description
protected abstract java.lang.Object	freshTarget() Obtain a fresh target object.
long	getLastRefreshTime() Return the last time an actual refresh happened (as timestamp).
long	getRefreshCount() Return the number of actual refreshes since startup.
java.lang.Object	getTarget() Return a target instance.
java.lang.Class<?>	getTargetClass() Return the type of targets returned by this TargetSource.
boolean	isStatic() Not static.
void	refresh() Refresh the underlying target object.
void	releaseTarget(java.lang.Object object) No need to release target.
protected boolean	requiresRefresh() Determine whether a refresh is required.
void	setRefreshCheckDelay(long refreshCheckDelay) Set the delay between refresh checks, in milliseconds.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final Log logger

Logger available to subclasses

targetObject

@Nullable
protected java.lang.Object targetObject

Constructor Detail

AbstractRefreshableTargetSource

public AbstractRefreshableTargetSource()

Method Detail

setRefreshCheckDelay

public void setRefreshCheckDelay(long refreshCheckDelay)

Set the delay between refresh checks, in milliseconds. Default is -1, indicating no refresh checks at all.

Note that an actual refresh will only happen when requiresRefresh() returns true.

getTargetClass

public java.lang.Class<?> getTargetClass()

Description copied from interface: TargetSource

Return the type of targets returned by this TargetSource.

Can return null, although certain usages of a TargetSource might just work with a predetermined target class.

Specified by:

getTargetClass in interface TargetClassAware

Specified by:

getTargetClass in interface TargetSource

Returns:

the type of targets returned by this TargetSource

isStatic

public boolean isStatic()

Not static.

Specified by:

isStatic in interface TargetSource

Returns:

true if the target is immutable

See Also:

TargetSource.getTarget()

getTarget

@Nullable
public final java.lang.Object getTarget()

Description copied from interface: TargetSource

Return a target instance. Invoked immediately before the AOP framework calls the "target" of an AOP method invocation.

Specified by:

getTarget in interface TargetSource

Returns:

the target object which contains the joinpoint, or null if there is no actual target instance

releaseTarget

public void releaseTarget(java.lang.Object object)

No need to release target.

Specified by:

releaseTarget in interface TargetSource

Parameters:

object - object obtained from a call to TargetSource.getTarget()

refresh

public final void refresh()

Description copied from interface: Refreshable

Refresh the underlying target object.

Specified by:

refresh in interface Refreshable

getRefreshCount

public long getRefreshCount()

Description copied from interface: Refreshable

Return the number of actual refreshes since startup.

Specified by:

getRefreshCount in interface Refreshable

getLastRefreshTime

public long getLastRefreshTime()

Description copied from interface: Refreshable

Return the last time an actual refresh happened (as timestamp).

Specified by:

getLastRefreshTime in interface Refreshable

requiresRefresh

protected boolean requiresRefresh()

Determine whether a refresh is required. Invoked for each refresh check, after the refresh check delay has elapsed.

The default implementation always returns true, triggering a refresh every time the delay has elapsed. To be overridden by subclasses with an appropriate check of the underlying target resource.

Returns:

whether a refresh is required

freshTarget

protected abstract java.lang.Object freshTarget()

Obtain a fresh target object.

Only invoked if a refresh check has found that a refresh is required (that is, requiresRefresh() has returned true).

Returns:

the fresh target object