day11 Spring AOP

2019-04-16 本文已影响0人老婆日向雏田

AOP (Aspect Oriented Programming)面向切面编程
OOP(Oriented Oriented Programming)面向对象编程
通过OOP的纵向和AOP的横向抽取，程序才可以真正解决问题
AOP的使用场景:日志事务

AOP基本上是通过代理机制实现的

单例模式
代理
工厂
装饰器
适配器
代理的对象为接口

AOP中一些概念的理解

aop adviser:切面
aop aspect:切面配置
aop pointuct:切点
adviser=advice+pointuct即切面=增强+切点（在哪里做什么）

Hello前置增强练习

给pom文件中添加aop依赖

<?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"
  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.spring</groupId>
  <artifactId>AOP</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>AOP</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <spring.version>5.0.10.RELEASE</spring.version>
    <aspectj.version>1.9.2</aspectj.version>
    <junit.version>4.12</junit.version>
    <log4j.version>1.2.17</log4j.version>
    <slf4j.version>1.7.12</slf4j.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <!-- <spring-test依赖>-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!--spring-context依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!--spring-aop依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!--aspectj依赖-->
    <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>
    <!--Lombok依赖-->
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.16.18</version>
    </dependency>
    <!-- log4j日志依赖 -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.6.6</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.6.6</version>
    </dependency>
  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

Hello接口及实现接口中方法的HelloImpl类

package com.spring;

public interface Hello {
    String getHello();
}

package com.spring;

public class HelloImpl implements Hello {
    @Override
    public String getHello() {
        return "Hello,Spring AOP";
    }
}

用户自定义的前置增强类MyBeforeAdvicelei

package com.spring;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/*
 * 用户自定义的前置增强类
 * */
public class MyBeforeAdvice {
    private  static final Logger logger= LoggerFactory.getLogger(MyBeforeAdvice.class);
    /*定义前置方法*/
    public void beforeMethod() {
        logger.info("This is a before method by wxy");
        logger.debug("This is a before method by wxy");


       // System.out.println("This is a before methoad");
    }

}

配置文件

<!--配置一个Hello的bean  等同于Hello hello = new HelloImpl();-->
   <bean id="hello" class="com.spring.HelloImpl"/>
       <!--配置一个MyBeforeAdvice前置增强的bean-->
       <bean id="mybeforeAdvice" class="com.spring.MyBeforeAdvice"/>
    <!--配置Aop-->
    <aop:config>
        <aop:aspect id="before" ref="mybeforeAdvice">
            <aop:pointcut id="myPointcut" expression="execution(* com.spring.*.*(..))"/>
            <aop:before method="beforeMethod" pointcut-ref="myPointcut"/>
        </aop:aspect>
    </aop:config>

主类

package com.spring;

import javafx.application.Application;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class HelloApp {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("/bean.xml");
        Hello hello = context .getBean(Hello.class);
        System.out.println(hello.getHello());
    }

}

运行结果

实战：模仿连接数据库的操作

UserDao接口

package com.spring;

public interface UserDao {
    void insert();
}

-UserDaoImpl类

package com.spring;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UserDaoImpl implements UserDao {
    private static final Logger logger= LoggerFactory.getLogger(UserDaoImpl.class);
    @Override
    public void insert() {
        logger.info("开始插入一条数据。。。");
    }
}

MyBeforeAdvice前置增强类

package com.spring;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/*
 * 用户自定义的前置增强类
 * */
public class MyBeforeAdvice {
    private  static final Logger logger= LoggerFactory.getLogger(MyBeforeAdvice.class);
    /*定义前置方法*/
    public void beforeMethod() {
        logger.info("This is a before method by wxy");
        logger.debug("This is a before method by wxy");


       // System.out.println("This is a before methoad");
    }

}

配置文件

<bean id="userDao" class="com.spring.UserDaoImpl"/>
    <bean id="beforeAdvice" class="com.spring.BeforeAdvice"/>
    <aop:config>
        <aop:aspect id="before1" ref="beforeAdvice">
            <aop:pointcut id="myPointcut1" expression="execution(* com.spring.*.*(..))"/>
            <aop:before method="connectDB" pointcut-ref="myPointcut1"/>
        </aop:aspect>
    </aop:config>

UserDao单元测试类

package com.spring;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.junit.Assert.*;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/bean.xml"})
public class UserDaoTest {
    @Autowired
    private UserDao userDao;
    @Test
    public void insert(){
        userDao.insert();
    }

}

运行结果

Snipaste_2019-03-10_10-36-10.png

实战：使用@AspectJ的例子

此例是演绎了一段“武松打虎”的情节——武松（Fighter）在山里等着老虎（Tiger）出现，只要发现老虎出来，就打老虎

1.定义业务类型

老虎（Tiger）类

package com.spring;

public class Tiger {

    public void walk(){
        System.out.println("Tiger is walking...");
    }

}

2.定义切面和配置

武松（Fighter）类

package com.spring;

import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;

@Aspect
public class Fighter {
    @Pointcut("execution(* com.spring.Tiger.walk())")
    public void foundTiger(){

    }
    @Before(value = "foundTiger()")
    public void foundBefore(){
        System.out.println("Fighter wait for tiger...");
    }

    @AfterReturning("foundTiger()")
    public void foundAfter(){
        System.out.println("Fighter flight with tiger...");
    }
}

相应的Spring配置

<!--启动AspectJ支持-->
    <aop:aspectj-autoproxy/>
    <!--定义bean-->
    <bean id="fighter " class="com.spring.Fighter"/>
    <bean id="tiger" class="com.spring.Tiger"/>

3.定义主应用

主应用定义为

package com.spring;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Application {
    public static void main(String[] args) {
        @SuppressWarnings("resources")
        ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
        Tiger tiger= context.getBean(Tiger.class);
        tiger.walk();
    }
}

4.运行

运行结果.png
本篇笔记出处@七夏港_f3ef

day11 Spring AOP

AOP基本上是通过代理机制实现的

AOP中一些概念的理解

Hello前置增强练习

实战：模仿连接数据库的操作

实战：使用@AspectJ的例子

1.定义业务类型

2.定义切面和配置

3.定义主应用

4.运行

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