Spring aop入門

AOP核心概念

一、橫切關注點

對哪些方法進行攔截，攔截後怎麼處理，這些關注點稱之爲橫切關注點

二、切面（aspect）

類是對物體特徵的抽象，切面就是對橫切關注點的抽象

三、鏈接點（joinpoint）

被攔截到的點，由於Spring只支持方法類型的鏈接點，因此在Spring中鏈接點指的就是被攔截到的方法，實際上鍊接點還能夠是字段或者構造器

四、切入點（pointcut）

對鏈接點進行攔截的定義

五、通知（advice）

所謂通知指的就是指攔截到鏈接點以後要執行的代碼，通知分爲前置、後置、異常、最終、環繞通知五類

六、目標對象

代理的目標對象

七、織入（weave）

將切面應用到目標對象並致使代理對象建立的過程

八、引入（introduction）

在不修改代碼的前提下，引入能夠在運行期爲類動態地添加一些方法或字段

進入實例代碼 

一、

package com.longteng.lesson2.dao;

import org.aspectj.lang.ProceedingJoinPoint;

public interface HelloWorld {
    void printHelloWorld();
    void doPrint();
}

 

二、

package com.longteng.lesson2.dao.impl;

import com.longteng.lesson2.dao.HelloWorld;

public class HelloWorldImpl implements HelloWorld {
    @Override
    public void printHelloWorld() {
        System.out.println("HelloWorldImpl:printHelloWorld()------------");
    }

    @Override
    public void doPrint() {
        System.out.println("HelloWorldImpl:doPrint()------------");
    }
}

 

三、

package com.longteng.lesson2.dao.impl;

import com.longteng.lesson2.dao.HelloWorld;

public class HelloWorldImpl1 implements HelloWorld {
    @Override
    public void printHelloWorld() {
        System.out.println("HelloWorldImpl1:printHelloWorld()------------");
    }

    @Override
    public void doPrint() {
        System.out.println("HelloWorldImpl1:doPrint()------------");
    }
}

 

四、

package com.longteng.lesson2.service;

public class TimeHandler {
    public void startTime()
    {
        System.out.println("CurrentTime = " + System.currentTimeMillis());
    }
    public void endTime()
    {
        try {
            Thread.sleep(3);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("EndTime = " + System.currentTimeMillis());
    }
}

 

五、

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <bean id="helloWorldImpl" class="com.longteng.lesson2.dao.impl.HelloWorldImpl"></bean>
    <bean id="helloWorldImpl1" class="com.longteng.lesson2.dao.impl.HelloWorldImpl1"></bean>
    <bean id="timeHandler" class="com.longteng.lesson2.service.TimeHandler"> </bean>
    <aop:config>
        <aop:aspect id="time" ref="timeHandler" order="1">
            <aop:pointcut id="addTime" expression="execution(* com.longteng.lesson2.dao.impl.HelloWorldImpl*.*(..))" />
            <aop:before method="startTime" pointcut-ref="addTime" />
            <aop:after method="endTime" pointcut-ref="addTime" />
        </aop:aspect>

    </aop:config>

</beans>

 

六、

package com.longteng.lesson2.dao;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class AopTest {
    ApplicationContext context;
    @Before
    public void initApplication(){
        context = new ClassPathXmlApplicationContext("aop.xml");
    }
    @Test
    public void test(){
        HelloWorld helloWorld1 =(HelloWorld) context.getBean("helloWorldImpl");
        helloWorld1.doPrint();
        helloWorld1.printHelloWorld();
        System.out.println("----------------------------------------");
        HelloWorld helloWorld2 =(HelloWorld) context.getBean("helloWorldImpl1");
        helloWorld2.doPrint();
        helloWorld2.printHelloWorld();
    }
}

 

七、測試結果

13:09:28.726 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'helloWorldImpl'
13:09:28.734 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
CurrentTime = 1544504968735
HelloWorldImpl:doPrint()------------
13:09:28.735 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
EndTime = 1544504968738
13:09:28.738 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
CurrentTime = 1544504968738
HelloWorldImpl:printHelloWorld()------------
13:09:28.738 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
EndTime = 1544504968741
----------------------------------------
13:09:28.741 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'helloWorldImpl1'
13:09:28.741 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
CurrentTime = 1544504968741
HelloWorldImpl1:doPrint()------------
13:09:28.741 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
EndTime = 1544504968745
13:09:28.745 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
CurrentTime = 1544504968745
HelloWorldImpl1:printHelloWorld()------------
13:09:28.745 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'timeHandler'
EndTime = 1544504968748

Process finished with exit code 0