public interface TargetSource extends TargetClassAware
TargetSource is used to obtain the current "target" of
 an AOP invocation, which will be invoked via reflection if no around
 advice chooses to end the interceptor chain itself.
 If a TargetSource is "static", it will always return
 the same target, allowing optimizations in the AOP framework. Dynamic
 target sources can support pooling, hot swapping, etc.
 
Application developers don't usually need to work with
 TargetSources directly: this is an AOP framework interface.
| Modifier and Type | Method and Description | 
|---|---|
| Object | getTarget()Return a target instance. | 
| Class<?> | getTargetClass()Return the type of targets returned by this  TargetSource. | 
| boolean | isStatic()Will all calls to  getTarget()return the same object? | 
| void | releaseTarget(Object target)Release the given target object obtained from the
  getTarget()method, if any. | 
@Nullable Class<?> getTargetClass()
TargetSource.
 Can return null, although certain usages of a TargetSource
 might just work with a predetermined target class.
getTargetClass in interface TargetClassAwareTargetSourceboolean isStatic()
getTarget() return the same object?
 In that case, there will be no need to invoke releaseTarget(Object),
 and the AOP framework can cache the return value of getTarget().
true if the target is immutablegetTarget()@Nullable Object getTarget() throws Exception
null if there is no actual target instanceException - if the target object can't be resolvedvoid releaseTarget(Object target) throws Exception
getTarget() method, if any.target - object obtained from a call to getTarget()Exception - if the object can't be released