第一个AOP

目录结构

pom文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.ly</groupId>
    <artifactId>demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
    <spring.version>4.2.5.RELEASE</spring.version>
        <!-- aspectj -->
        <aspectj.version>1.7.4</aspectj.version>

        <!-- cglib -->
        <cglib.version>3.0</cglib.version>
    </properties>


    <dependencies>
        <!-- SPRING begin -->

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>${aspectj.version}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>${aspectj.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>${cglib.version}</version>
        </dependency>
        <dependency>
            <groupId>org.testng</groupId>
            <artifactId>testng</artifactId>
            <version>RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- SPRING end -->
    </dependencies>

</project>

package java_study.aopdemo;

/**
 * Created  on 2018/4/8.
 */

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;

/**
 * 注解方式声明aop
 * 1.用@Aspect注解将类声明为切面(如果用@Component("")注解注释为一个bean对象，那么就要在spring配置文件中开启注解扫描，<context:component-scan base-package="com.cjh.aop2"/>
 *      否则要在spring配置文件中声明一个bean对象)
 * 2.在切面需要实现相应方法的前面加上相应的注释，也就是通知类型。
 * 3.此处有环绕通知，环绕通知方法一定要有ProceedingJoinPoint类型的参数传入，然后执行对应的proceed()方法，环绕才能实现。
 */
@Component("annotationTest")
@Aspect
public class AnnotationTest {
    //定义切点
    @Pointcut("execution(* *.saying(..))")
    public void sayings(){}
    /**
     * 前置通知(注解中的sayings()方法，其实就是上面定义pointcut切点注解所修饰的方法名，那只是个代理对象,不需要写具体方法，
     * 相当于xml声明切面的id名，如下，相当于id="embark",用于供其他通知类型引用)
     * <aop:config>
     <aop:aspect ref="mistrel">
     <!-- 定义切点 -->
     <aop:pointcut expression="execution(* *.saying(..))" id="embark"/>
     <!-- 声明前置通知 (在切点方法被执行前调用) -->
     <aop:before method="beforSay" pointcut-ref="embark"/>
     <!-- 声明后置通知 (在切点方法被执行后调用) -->
     <aop:after method="afterSay" pointcut-ref="embark"/>
     </aop:aspect>
     </aop:config>
     */
    @Before("sayings()")
    public void sayHello(){
        System.out.println("注解类型前置通知");
    }
    //后置通知
    @After("sayings()")
    public void sayGoodbey(){
        System.out.println("注解类型后置通知");
    }
    //环绕通知。注意要有ProceedingJoinPoint参数传入。
    @Around("sayings()")
    public void sayAround(ProceedingJoinPoint pjp) throws Throwable{
        System.out.println("注解类型环绕通知..环绕前");
        pjp.proceed();//执行方法
        System.out.println("注解类型环绕通知..环绕后");
    }
}

package java_study.aopdemo;

import org.springframework.stereotype.Component;

/**
 * 
 */
@Component("knight")
public class BraveKnight {
    public void saying(){
        System.out.println("我是骑士..（切点方法）");
    }
}

package java_study;


import java_study.aopdemo.BraveKnight;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created  on 2018/3/30.
 */
public class MyMainDemo {
    public static void main(String[] args){
        ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
        BraveKnight br = (BraveKnight) ac.getBean("knight");
        br.saying();
    }
}

最后结果：