aop的两种配置方法

一、实现接口并重写方法

实现org.aopalliance.intercept.MethodInterceptor接口，这是AOP Alliance规范中的接口，Spring AOP支持它。这种方式比较适合需要非常细粒度控制的场景。

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

public class LoggingInterceptor implements MethodInterceptor {

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        System.out.println("Before method: " + invocation.getMethod().getName());
        try {
            Object result = invocation.proceed(); // 继续执行被拦截的方法
            return result;
        } finally {
            System.out.println("After method: " + invocation.getMethod().getName());
        }
    }
}

在spring配置中,将此拦截器注册到切面中

<aop:config>
    <aop:aspect id="loggingAspect" ref="loggingInterceptor">
        <aop:pointcut id="serviceMethods" expression="execution(* com.example.service.*.*(..))"/>
        <aop:around method="invoke" pointcut-ref="serviceMethods"/>
    </aop:aspect>
</aop:config>

<bean id="loggingInterceptor" class="com.example.aspect.LoggingInterceptor"/>

二、通过注解方式(以环绕通知为例)

@Aspect
@Component
public class LoggingAspect {

    @Around("execution(* com.example.service.*.*(..))")
    public Object logAround(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("Before method: " + joinPoint.getSignature().getName());
        try {
            Object result = joinPoint.proceed();
            return result;
        } finally {
            System.out.println("After method: " + joinPoint.getSignature().getName());
        }
    }
}