Package org.springframework.aop.target

Class HotSwappableTargetSource

java.lang.Object

org.springframework.aop.target.HotSwappableTargetSource

All Implemented Interfaces:

Serializable, TargetClassAware, TargetSource

public class HotSwappableTargetSource
extends Object
implements TargetSource, Serializable

TargetSource implementation that caches a local target object, but allows the target to be swapped while the application is running.

If configuring an object of this class in a Spring IoC container, use constructor injection.

This TargetSource is serializable if the target is at the time of serialization.

Author:

Rod Johnson, Juergen Hoeller

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
HotSwappableTargetSource(Object initialTarget)	Create a new HotSwappableTargetSource with the given initial target object.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)	Two HotSwappableTargetSources are equal if the current target objects are equal.
Object	getTarget()	Return a target instance.
Class<?>	getTargetClass()	Return the type of the current target object.
int	hashCode()
final boolean	isStatic()	Will all calls to TargetSource.getTarget() return the same object?
void	releaseTarget(Object target)	Release the given target object obtained from the TargetSource.getTarget() method, if any.
Object	swap(Object newTarget)	Swap the target, returning the old target object.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

HotSwappableTargetSource

public HotSwappableTargetSource(Object initialTarget)

Create a new HotSwappableTargetSource with the given initial target object.

Parameters:

initialTarget - the initial target object

Method Details

getTargetClass

public Class<?> getTargetClass()

Return the type of the current target object.

The returned type should usually be constant across all target objects.

Specified by:

getTargetClass in interface TargetClassAware

Specified by:

getTargetClass in interface TargetSource

Returns:

the type of targets returned by this TargetSource

isStatic

public final boolean isStatic()

Description copied from interface: TargetSource

Will all calls to TargetSource.getTarget() return the same object?

In that case, there will be no need to invoke TargetSource.releaseTarget(Object), and the AOP framework can cache the return value of TargetSource.getTarget().

Specified by:

isStatic in interface TargetSource

Returns:

true if the target is immutable

See Also:

• TargetSource.getTarget()

getTarget

public 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(Object target)

Description copied from interface: TargetSource

Release the given target object obtained from the TargetSource.getTarget() method, if any.

Specified by:

releaseTarget in interface TargetSource

Parameters:

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

swap

public Object swap(Object newTarget)
            throws IllegalArgumentException

Swap the target, returning the old target object.

Parameters:

newTarget - the new target object

Returns:

the old target object

Throws:

IllegalArgumentException - if the new target is invalid

equals

public boolean equals(Object other)

Two HotSwappableTargetSources are equal if the current target objects are equal.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object