Spring-aop编程之前置通知

雨点打透心脏的1/2处 2023-07-18 02:43 5阅读 0赞

### Spring-aop编程之前置通知 ###

##### aop（ Aspect-Oriented Programming）前置通知原理案例讲解 #####

编程步骤；

1.  定义接口
2.  编写对象（被代理的对象即目标对象）
3.  编写通知（前置通知即目标方法调用前调用）
4.  在beans.xml文件中配置

4.1. 配置  被代理对象即目标对象

4.2. 配置通知

4.3. 配置代理对象  其是ProxyFactoryBean的对象实例

4.3.1 配置代理接口集

4.3.2 织入通知

4.3.3 配置被代理对象

直接上代码

1.分别创建两个接口如下：

TestServiceInterface.java接口

1 package com.LHB.aop;
    2
    3 public interface TestServiceInterface {
    4
    5     public void sayHello();
    6 }

TestServiceInterface2.java接口

1 package com.LHB.aop;
    2
    3 public interface TestServiceInterface2 {
    4
    5     public void sayBye();
    6 }

2. 创建被代理对象（目标对象）类testService.java，该类实现了TestServiceInterface和TestServiceInterface2两个接口方法

1 package com.LHB.aop;
     2
     3 public class testService implements TestServiceInterface,TestServiceInterface2 {
     4
     5     private String name;
     6     public String getName() {
     7         return name;
     8     }
     9     public void setName(String name) {
    10         this.name = name;
    11     }
    12     @Override
    13     public void sayHello() {
    14         // TODO Auto-generated method stub
    15
    16         System.out.println("hello " + name);
    17     }
    18     @Override
    19     public void sayBye() {
    20         // TODO Auto-generated method stub
    21         System.out.println("Bye "+ name);
    22     }
    23
    24 }

3. 编写前置通知即MyMethodBeforeAdvice.java,该类实现了MethodBeforeAdvice接口中的before（method method，Object\[\] args，Object target ）方法。

**注意：在实现该接口的时候需要导入spring-aop-5.0.1.RELEASE.jar包（本案例在spring5.0.1版本下实现的）**

1 package com.LHB.aop;
     2
     3 import java.lang.reflect.Method;
     4
     5 import org.springframework.aop.MethodBeforeAdvice;
     6
     7 public class MyMethodBeforeAdvice implements MethodBeforeAdvice {
     8
     9     /**
    10      * 功能：该函数将在目标函数执行前首先执行
    11      * method:被调用方法名字
    12      * args：给method传递的参数
    13      * target：被代理的目标对象
    14      */
    15     @Override
    16     public void before(Method method, Object[] args, Object target)
    17             throws Throwable {
    18         // TODO Auto-generated method stub
    19         //method.getName()方法将得到目标函数的函数名称
    20         System.out.println("记录日志...." + method.getName());
    21     }
    22
    23 }

4.通过new/File新建一个bean.xml配置文件，开始配置前置通知

1 <?xml version="1.0" encoding="UTF-8"?>
     2 <beans xmlns="http://www.springframework.org/schema/beans"
     3        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     4        xmlns:context="http://www.springframework.org/schema/context"
     5        xsi:schemaLocation="http://www.springframework.org/schema/beans
     6                 http://www.springframework.org/schema/beans/spring-beans.xsd
     7                 http://www.springframework.org/schema/context
     8                 http://www.springframework.org/schema/context/spring-context.xsd">
     9           
    10                 
    11    <bean id="testService" class="com.LHB.aop.testService">
    12        <property name="name" value="张三" />
    13    </bean>
    14    
    15    <bean id="MyMethodBeforeAdvice" class="com.LHB.aop.MyMethodBeforeAdvice" />
    16    
    17    <bean id="ProxyFactoryBean" class="org.springframework.aop.framework.ProxyFactoryBean">
    18        
    19        <property name="proxyInterfaces">
    20                 <list>
    21                     <value>com.LHB.aop.TestServiceInterface</value>
    22                     <value>com.LHB.aop.TestServiceInterface2</value>
    23                 </list>   
    24        </property>
    25        
    26    <property name="interceptorNames">
    27        
    28        <value>MyMethodBeforeAdvice</value>
    29    </property>
    30    
    31    <property name="target" ref="testService"/>
    32
    33    </bean>
    34    
    35 </beans>

5. 创建一个测试类APP

1 package com.LHB.aop;
     2
     3 import org.springframework.context.ApplicationContext;
     4 import org.springframework.context.support.ClassPathXmlApplicationContext;
     5
     6 public class App {
     7
     8     public static void main(String[] args) {
     9         // TODO Auto-generated method stub
    10         ApplicationContext ac = new ClassPathXmlApplicationContext("com/LHB/aop/beans.xml");
    11         TestServiceInterface tsi = (TestServiceInterface) ac.getBean("ProxyFactoryBean");
    12         tsi.sayHello();
    13         ((TestServiceInterface2)tsi).sayBye();
    14         
    15     }
    16
    17 }

6.  运行结果

![1230005-20171202222715194-1821068897.png][]

** **

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**持续更新中…**

**文章参考学习地址：[https://www.cnblogs.com/lihuibin/p/7955947.html][https_www.cnblogs.com_lihuibin_p_7955947.html]**

[1230005-20171202222715194-1821068897.png]: /images/20230528/774d0fb76f4b49d3850da587dee3b5a2.png
[https_www.cnblogs.com_lihuibin_p_7955947.html]: https://www.cnblogs.com/lihuibin/p/7955947.html