（二）Spring框架学习--AOP

AOP 即 Aspect Oriented Program 面向切面编程
首先，在面向切面编程的思想里面，把功能分为核心业务功能，和周边功能。
所谓的核心业务，比如登陆，增加数据，删除数据都叫核心业务
所谓的周边功能，比如性能统计，日志，事务管理等等

周边功能在Spring的面向切面编程AOP思想里，即被定义为切面

在面向切面编程AOP的思想里面，核心业务功能和切面功能分别独立进行开发
然后把切面功能和核心业务功能 "编织" 在一起，这就叫AOP

代码

maven依赖

<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>5.0.8.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.8.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <version>5.0.8.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>5.0.8.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>5.0.8.RELEASE</version>
    </dependency>

package cn.why.test1.aspect;

import org.aspectj.lang.ProceedingJoinPoint;

/**
 * Title:           LoggerAspect
 * Description:
 * Company:         AceGear
 * Author:          henrywang
 * Date:            2018/8/2
 * JDK:             8
 * Encoding:        UTF-8
 */
public class LoggerAspect {
    public Object log(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("start log:"+ joinPoint.getSignature().getName());
        Object object = joinPoint.proceed();
        System.out.println("end log: "+joinPoint.getSignature().getName());
        return object;
    }
}

package cn.why.test1.pojo;

/**
 * Title:           Category
 * Description:
 * Company:         AceGear
 * Author:          henrywang
 * Date:            2018/8/2
 * JDK:             8
 * Encoding:        UTF-8
 */
public class Category {
    private int id;
    private String name;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package cn.why.test1.pojo;

/**
 * Title:           Producgt
 * Description:
 * Company:         AceGear
 * Author:          henrywang
 * Date:            2018/8/2
 * JDK:             8
 * Encoding:        UTF-8
 */
public class Product {
    private int id;
    private String name;
    private Category category;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Category getCategory() {
        return category;
    }

    public void setCategory(Category category) {
        this.category = category;
    }
}

package cn.why.test1.service;

/**
 * Title:           ProductService
 * Description:
 * Company:         AceGear
 * Author:          henrywang
 * Date:            2018/8/2
 * JDK:             8
 * Encoding:        UTF-8
 */
public class ProductService {
    public void doSomeService(){
        System.out.println("doSomeService");
    }
}

package cn.why.test1.test;

import cn.why.test1.service.ProductService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Title:           TestSpring
 * Description:
 * Company:         AceGear
 * Author:          henrywang
 * Date:            2018/8/2
 * JDK:             8
 * Encoding:        UTF-8
 */
public class TestSpring {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"applicationContext2.xml"});
        ProductService s = (ProductService) context.getBean("s");
        s.doSomeService();
    }
}

applicationContext2.xml

<?xml version="1.0" encoding="utf-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="
   http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/aop
   http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
   http://www.springframework.org/schema/tx
   http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    <bean name="c" class="cn.why.test1.pojo.Category">
        <property name="name" value="yyy"/>
    </bean>
    <bean name="p" class="cn.why.test1.pojo.Product">
        <property name="name" value="product1"/>
        <property name="category" ref="c"/>

    </bean>
    <bean name="s" class="cn.why.test1.service.ProductService"/>
    <bean id = "loggerAspect" class="cn.why.test1.aspect.LoggerAspect"/>
    <aop:config>
        <aop:pointcut id="loggerCutpoint" expression="execution(* cn.why.test1.service.ProductService.*(..))"/>
        <aop:aspect id="logAspect" ref="loggerAspect">
            <aop:around method="log" pointcut-ref="loggerCutpoint"/>
        </aop:aspect>
    </aop:config>
</beans>

整体结构