spring 入门实战（四） Aop

妖狐艹你老母 2022-05-27 22:40 192阅读 0赞

# spring aop实战 #

> 本篇只是用实际案例帮助快速入门，不涉及具体概念

#### 1.0 开发环境 ####

1.0 开发工具 eclipse
     2.0 jar包  除了Spring jar包外，还需要其他jar包  spring本身并没有提供  我也不知为什么
     https://pan.baidu.com/s/16MTV5K8zG8m9cROC-6G_iQ  提取码：hro2

#### 2.0 搭建主业务模块 Affairs.java ####

package com.ccut.aop;
    
    import java.io.IOException;
    
    public class Affairs {
    
        private String message1;
        private String message2;
    
    
        public Affairs(){}
    
    
        public String getMessage1() {
            return message1;
        }
    
        public void setMessage1(String message1) {
            this.message1 = message1;
        }
    
        public String getMessage2() {
            return message2;
        }
    
        public void setMessage2(String message2) {
            this.message2 = message2;
        }
    
        public void PersonA(){
            System.out.println("A 这个人说啊："+this.getMessage1());
        }
    
        public void PersonB(){
            System.out.println("B 这个人说啊："+this.getMessage2());
        }
    
    
        public void error(){
            System.out.println("error!!!");
            int i = 10;
            if(i != 1){
                throw new IllegalArgumentException("这是参数异常");
            }
    
        }
    
    
    
    }

#### 3.0 搭建切面功能类Function ####

package com.ccut.aop;
    
    import org.aspectj.lang.ProceedingJoinPoint;
    
    public class Function {
            private String fmessage;
            private String mmessage;
            public Function(){}
            public String getFmessage() {
                return fmessage;
            }
            public void setFmessage(String fmessage) {
                this.fmessage = fmessage;
            }
            public String getMmessage() {
                return mmessage;
            }
            public void setMmessage(String mmessage) {
                this.mmessage = mmessage;
            }
    
            public void f(){
                System.out.println(this.getFmessage());
            }
    
            public void around(ProceedingJoinPoint pj){
                System.out.println("在目标函数之前执行");
                try {
                    pj.proceed();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }finally{
                    System.out.println("在目标函数之后执行");
                }
            }
    
            public void m(){
                System.out.println(this.getMmessage());
            }
    
            public void mess(String msg){
                System.out.println(msg+" 这是返回后的信息");
            }
    
            public void err(Throwable ex){
                System.out.println("这个错误是："+ex);
            }
    
    }

#### 4.0 搭建测试类 Test.java ####

package com.ccut.test;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import com.ccut.aop.Affairs;
    
    public class Test {
        public static void main(String[] args) {
    
            ApplicationContext applicationContext = 
            new ClassPathXmlApplicationContext("./resources/aop.xml");
    
            Affairs affairs = (Affairs) applicationContext.getBean("affairs");
            affairs.PersonA();
            affairs.PersonB();
    
        }
    }

上面是公共的，也就是说下面的测试都用的是上面的代码

--------------------

#### 5.0 编写配置文件aop.xml 位于resources文件夹内（这是整合后的，单个功能的配置文件在后面 暂时不用看这个） ####

<?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:p="http://www.springframework.org/schema/p"
        xmlns:context="http://www.springframework.org/schema/context"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-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/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
    
        <aop:config>
            <aop:aspect id="aspect1" ref="function">
                <aop:pointcut id="personA" expression="execution(* com.ccut.aop.Affairs.PersonA())"/> 
                <aop:pointcut id="personB" expression="execution(* com.ccut.aop.Affairs.PersonB())"/>           
                
                <aop:around method="around" pointcut-ref="personB"/>
            </aop:aspect>
        </aop:config>
    
        <bean id="affairs" class = "com.ccut.aop.Affairs">
            <property name="message1" value="我就是 A 啊 这有什么疑问吗？"/>
            <property name="message2" value="我就是 B 啊 这有什么疑问吗？"/>
        </bean>
    
        <bean id = "function" class="com.ccut.aop.Function">
            <property name="fmessage" value="我可能在你前面执行！"></property>
            <property name="mmessage" value="我可能在你后面执行呢！"></property>
        </bean>
    
    
    
        </beans>

##### 5.1 我们把上面的配置文件拆开看，以便更好的理解 #####

> aop的切入形式有一下几种

<aop:before  method= ''beforemethod'',pointcut-ref="cut1"/> <aop:after  method= ''aftermethod'',pointcut-ref="cut2"/> <aop:after-returning method="mess" returning="msg" pointcut-ref="return"/> <aop:around method="around" pointcut-ref="personB"/> <aop:after-throwing method="" pointcut-ref="" throwing=""/> <aop:declare-parents/>这个暂时不解释

上面的简化后的配置文件实现了对事物类 和切面类相关参数的注入  
执行简化后的配置文件的结果为：  
![这里写图片描述][70]

##### 5.2.1 下面是把功能类的某一方法切入到切入点前面执行的aop.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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-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/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
    
        <aop:config>
            <aop:aspect id="aspect1" ref="function">
    
                <aop:pointcut id="personA" expression="execution(* com.ccut.aop.Affairs.PersonA())"/>   
                         
                <aop:before pointcut-ref="personA" method="f"/>
                <-- 上面是以后要改动的代码↑↑↑↑↑↑↑-->
            </aop:aspect>
        </aop:config>
    
        <bean id="affairs" class = "com.ccut.aop.Affairs">
            <property name="message1" value="我就是 A 啊 这有什么疑问吗？"/>
            <property name="message2" value="我就是 B 啊 这有什么疑问吗？"/>
        </bean>
    
        <bean id = "function" class="com.ccut.aop.Function">
            <property name="fmessage" value="我可能在你前面执行！"></property>
            <property name="mmessage" value="我可能在你后面执行呢！"></property>
        </bean>
    
        </beans>

执行结果：  
![这里写图片描述][70 1]

##### 5.2.2 把指定方法放在切入点后面执行 #####

配置文件对应位置改为

<aop:after method="m" pointcut-ref="personA"/>

结果为：  
![这里写图片描述][70 2]

##### 5.2.3 在指定方法结束时候执行 #####

配置文件如下

<aop:config>
            <aop:aspect id="aspect1" ref="function">        
                <aop:pointcut id="return" expression="execution(* com.ccut.aop.Affairs.*(..))"/>        
    
            <aop:after-returning method="mess" returning="msg" pointcut-ref="return"/>
    
            </aop:aspect>
        </aop:config>

测试类：

package com.ccut.test;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import com.ccut.aop.Affairs;
    
    public class Test {
        public static void main(String[] args) {
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext("./resources/aop.xml");
    
            Affairs affairs = (Affairs) applicationContext.getBean("affairs");
            affairs.PersonA();
            affairs.PersonB();
    
            affairs.getMessage1();
    
    
        }
    }

结果：  
![这里写图片描述][70 3]

##### 5.2.4 抛出异常后执行 aop:after-throwing 这个方法不能完全处理异常 最终还是会交给jvm #####

配置文件：  
把上面的 < aop:after-returning method=”mess” returning=”msg” pointcut-ref=”return”/> 替换为下面的

<aop:after-throwing method="err" throwing="ex" pointcut-ref="return"/>

主方法中的affairs.getMessage1();改为下面

affairs.error();

结果：  
![这里写图片描述][70 4]

##### 5.2.5 环绕通知增强 aop:around #####

配置文件：

<?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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-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/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
    
        <aop:config>
            <aop:aspect id="aspect1" ref="function">
    
                <aop:pointcut id="personB" expression="execution(* com.ccut.aop.Affairs.PersonB())"/>           
                <aop:around method="around" pointcut-ref="personB"/>
            </aop:aspect>
        </aop:config>
    
        <bean id="affairs" class = "com.ccut.aop.Affairs">
            <property name="message1" value="我就是 A 啊 这有什么疑问吗？"/>
            <property name="message2" value="我就是 B 啊 这有什么疑问吗？"/>
        </bean>
    
        <bean id = "function" class="com.ccut.aop.Function">
            <property name="fmessage" value="我可能在你前面执行！"></property>
            <property name="mmessage" value="我可能在你后面执行呢！"></property>
        </bean>
    
    
    
        </beans>

测试类：

package com.ccut.test;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import com.ccut.aop.Affairs;
    
    public class Test {
        public static void main(String[] args) {
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext("./resources/aop.xml");
    
            Affairs affairs = (Affairs) applicationContext.getBean("affairs");
            affairs.PersonA();
            affairs.PersonB();
        }
    }

结果：  
![这里写图片描述][70 5]

> 这里注意 环绕通知方法重点一定要有下面这个形参ProceedingJoinPoint pj 如果没有 pj.proceed();这个代码  
> 则被切入的函数不会执行

public void around(ProceedingJoinPoint pj){
                System.out.println("在目标函数之前执行");
                try {
                    pj.proceed();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }finally{
                    System.out.println("在目标函数之后执行");
                }
            }

这里的< aop:declare-parents/>这个暂时不解释

[70]: /images/20220528/603fdf9052a44cf18d3f080aa7c40d72.png
[70 1]: /images/20220528/9cad2a88c3dd4212b64bd620dc3e975a.png
[70 2]: /images/20220528/08e9bae4c0c245beab755f71e225beb6.png
[70 3]: /images/20220528/65564188d20d46acb8a71117676ce8a2.png
[70 4]: /images/20220528/62ad0d69415f4fe9b6f5943f422ebab3.png
[70 5]: /images/20220528/8a2638f28ba74975a118c5c1ab895d03.png