34.5、Spring

 把切面理解为方面

package com.hhh.aop;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.ThrowsAdvice;

import java.lang.reflect.Method;

public class MyAspect implements MethodBeforeAdvice , AfterReturningAdvice , MethodInterceptor , ThrowsAdvice {
    
    @Override
    public void before(Method method, Object[] objects, Object o) throws Throwable {
        System.out.println("Before..."+method.getName());
    }

    
    @Override
    public void afterReturning(Object o, Method method, Object[] objects, Object o1) throws Throwable {
        System.out.println("After..."+method.getName());
    }

    
    @Override
    public Object invoke(MethodInvocation methodInvocation) throws Throwable {
        System.out.println("Around...Before"+methodInvocation.getMethod().getName());
        Object obj = methodInvocation.proceed(); //执行目标方法
        System.out.println("Around...After"+methodInvocation.getMethod().getName());
        return obj;
    }
}

切面是对业务层做增强的

 测试：

 修改业务层：

 创建切面：

 测试：