Aop implementation Interface Method

Before advice: A notification executed Before a connection point. However, this notification cannot prevent the execution process Before the connection point (unless it throws an exception ).
After returning advice: a notification that is executed After a connection point is completed normally. For example, a method does not throw any exception and returns a normal result.
After throwing advice: the notification that is executed when the method throws an exception and exits.
After (finally) advice: the notification executed when a connection point exits (whether it is a normal return or an abnormal exit ).
Around Advice: a notification that surrounds a connection point, such as a method call. This is the most powerful notification type. Surround notifications can complete custom actions before and after method calls. It will also choose whether to continue executing the connection point or directly return its own return value or throw an exception to end the execution.
1. Surround notification:
[Java]
Public class LogInterceptor implements MethodInterceptor {
 
@ Override
Public Object invoke (MethodInvocation arg0) throws Throwable {
// TODO Auto-generated method stub
System. out. println ("aop begin ");
Object obj = arg0.proceed ();
System. out. println ("aop end ");
Return obj;
}
}

2. pre-notification:
[Java]
Public class BeforInterceptor implements MethodBeforeAdvice {
 
@ Override
Public void before (Method arg0, Object [] arg1, Object arg2)
Throws Throwable {
// TODO Auto-generated method stub
System. out. println ("BeforInterceptor ");
System. out. println ("Entry Point Object:" + arg2 + "parameter:" + arg1 [0] + "entry point:" + arg0.getName ());
}
 
}

3. Post-notification:
[Java]
Public class AfterInterceptor implements AfterReturningAdvice {
@ Override
Public void afterReturning (Object arg0, Method arg1, Object [] arg2,
Object arg3) throws Throwable {
// TODO Auto-generated method stub
System. out. println (arg0 + "" + arg3 );
}
}
4. Exception notification:
ThrowsAdvice is a label interface. We can define one or more classes to capture exceptions thrown by bean defining exception notifications, and execute corresponding methods before throwing exceptions.
[Java] view plaincopy
Public class ExceptionInterceptor implements ThrowsAdvice {
Public void afterThrowing (Exception e ){
System. out. println (e );
System. out. println ("ExceptionInterceptor Exception ");
}
Public void afterThrowing (NullPointerException e ){
System. out. println (e );
System. out. println ("ExceptionInterceptor NullPointerException ");
}
}
After an Exception notification is intercepted, no other methods will be executed. For example, if NullPointerException is intercepted, no Exception will be intercepted.

Xml:
[Html]
<Aop: config>
<Aop: pointcut expression = "execution (* org. han. service .*.*(..))"
Id = "logpoint"/>
<! -- Surround notification -->
<Aop: advisor advice-ref = "loginter1" pointcut-ref = "logpoint"/>
 
<! -- Pre-notification -->
<Aop: advisor advice-ref = "loginter2" pointcut-ref = "logpoint"/>
 
<! -- Post-notification -->
<Aop: advisor advice-ref = "loginter3" pointcut-ref = "logpoint"/>

<! -- Exception notification -->
<Aop: advisor advice-ref = "loginter4" pointcut-ref = "logpoint"/>
</Aop: config>

Services:
[Java]
Public class LoginService {
Public void login (){
System. out. println ("yyy logging on ");
User u = null;
System. out. println (u. getUname ());
System. out. println ("xxx is logged on ");
}
Public User register (){
System. out. println ("registered successfully ");
Return new User ("han", "zhou ");
}
Public User getUser (String uname, String pwd ){
System. out. println ("getUser ");
Return new User (uname, pwd );
}
Public void login (String uname ){
System. out. println (uname + "logging in ");
}
}

Author: hanzhou4519