Spring中的四種增強有那四種？

前置增強 後置增強 環繞增強 異常增強

先編寫接口和實體類 ISomeService和SomeServiceImpl

package demo10;

/**
 * Created by mycom on 2018/3/8.
 */
public interface ISomeService {
    public void doSome();
}

package demo10;

/**
 * Created by mycom on 2018/3/8.
 */
public class SomeServiceImpl implements ISomeService {
    
 
public void doSome() {
        System.out.println("=================");
    }
}

先來說第一個前置增強，直接用例子來說明

package demo10;

import org.springframework.aop.MethodBeforeAdvice;

import java.lang.reflect.Method;

/**
 * Created by mycom on 2018/3/8.
 */
public class BeforeAdvice implements MethodBeforeAdvice {
    
 
public void before(Method method, Object[] objects, Object o) throws Throwable {
        System.out.println("=========before");
    }
}

在配置文件中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance
 
"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id="service" class="demo10.SomeServiceImpl"></bean>
    <bean id="beforeAdvice" class="demo10.BeforeAdvice"></bean>
    <bean id="proxyService" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="target" ref="service"></property>
        <property name="interceptorNames" value="beforeAdvice"></property>
    </bean>


</beans>

@Test
    public void t1(){
        ApplicationContext context=new ClassPathXmlApplicationContext("applicationContextBefore.xml");
        ISomeService proxyService =(ISomeService) context.getBean("proxyService");
        proxyService.doSome();
    }

運行的結果是

2.後置增強和前置增強一樣，只是改一改配置文件裏的名稱就可以

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id="service" class="demo11.SomeServiceImpl"></bean>
    <bean id="afterAdvice" class="demo11.AfterAdvice"></bean>
    <bean id="proxyService" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="target" ref="service"></property>
        <property name="interceptorNames" value="afterAdvice"></property>
    </bean>


</beans>

3.環繞增強

直接飲用上面的接口和實現類了

在創建另一個類 MethodAdvice

package demo12;


import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

/**
 * Created by mycom on 2018/3/8.
 */
public class MethodAdvice implements MethodInterceptor {


    public Object invoke(MethodInvocation methodInvocation) throws Throwable {
        System.out.println("前置增強");
        Object result = methodInvocation.proceed();
        System.out.println("後置增強");
        return result;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id="service" class="demo12.SomeServiceImpl"></bean>
    <bean id="methodAdvice" class="demo12.MethodAdvice"></bean>
    <bean id="proxyService" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="target" ref="service"></property>
        <property name="interceptorNames" value="methodAdvice"></property>
    </bean>


</beans>

4.異常增強

package demo13;


import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.ThrowsAdvice;

/**
 * Created by mycom on 2018/3/8.
 */
public class MyThroesAdvice implements ThrowsAdvice {
    public void afterThrowing(Exception ex){
        System.out.println("網絡出現錯誤");
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id="service" class="demo13.SomeServiceImpl"></bean>
    <bean id="throwsAdvice" class="demo13.MyThroesAdvice"></bean>
    <bean id="proxyService" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="target" ref="service"></property>
        <property name="interceptorNames" value="throwsAdvice"></property>
    </bean>


</beans>

@Test
   public void t2(){
       ApplicationContext context=new ClassPathXmlApplicationContext("applicationContextThrows.xml");
       ISomeService proxyService =(ISomeService) context.getBean("proxyService");
       try{
           proxyService.doSome();
       }catch (Exception ex){
           ex.printStackTrace();
       }

5.advisor 是顧問的意思 正對某一個方法增強

還有一個詞是通知 advice 我自己的理解是 通知視同只所有人，顧問是針對某個人顧問，這樣方便記憶

現在在ISomeService接口中在添加一個方法doAny（），在實現類中重寫這個方法

那麽在配置文件中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id="service" class="demo14.SomeServiceImpl"></bean>
    <bean id="beforeAdvice" class="demo14.BeforeAdvice"></bean>
    
    <!--與其他不一樣的地方-->
    <bean id="advisor" class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">
        <property name="advice" ref="beforeAdvice"></property>
        <property name="mappedNames" value="do*"></property>
    </bean>
    <bean id="proxyService" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="target" ref="service"></property>
        <property name="interceptorNames" value="advisor"></property>
    </bean>


</beans>

這個配置文件可以對比著之前寫的配置文件看看有什麽不同之處

@Test
   public void t2(){
       ApplicationContext context=new ClassPathXmlApplicationContext("applicationContextAdvisor.xml");
       ISomeService proxyService =(ISomeService) context.getBean("proxyService");
       proxyService.doSome();
       proxyService.doAny();
   }

Spring（七）Spring中的四種增強和顧問