文章目錄

• 概述
• 實例
• • target()
  • this()

概述

target()切點函數通過判斷目標類是否按類型匹配指定類來決定連接點是否匹配. 用于匹配當前目標對象類型的執行方法；注意是目標對象的類型匹配，這樣就不包括引入接口也類型匹配；

this()切點函數則通過判斷代理類是否按類型匹配指定類來決定是否和切點匹配。 用于匹配當前AOP代理對象類型的執行方法；注意是AOP代理對象的類型匹配，這樣就可能包括引入接口也類型匹配。 this中使用的表達式必須是類型全限定名，不支持通配符。

兩者都僅接受類名的入參，雖然類名可以帶“+”，但是對于這兩個函數來講，使用或者不是用，效果完全相同。

---

實例

代碼已托管到Github—> https://github.com/yangshangwei/SpringMaster

---

target()

target(M)表示如果目標類按類型匹配于M，這目標類的所有方法都匹配切點。

• target(com.xgj.IBussiness) ：IBussiness為接口，匹配接口實現類中所有方法，包括未在接口中聲明的方法
• target(com.xgj.IBussiness)等同于target(com.xgj.IBussiness+)

接口

package com.xgj.aop.spring.advisor.aspectJ.function.target;public interface IBussinessService {String doSomething();}

目標Bean

package com.xgj.aop.spring.advisor.aspectJ.function.target;import org.springframework.stereotype.Component;/*** * * @ClassName: BussinessService* * @Description: @Component標注的bean* * @author: Mr.Yang* * @date: 2017年9月5日 下午8:18:03*/@Component public class BussinessService {public String doSomething() {System.out.println("doSomething executed");return "success";} }

切面

package com.xgj.aop.spring.advisor.aspectJ.function.target;import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.Aspect;/*** * * @ClassName: TargetAspect* * @Description: @Aspect標注的切面* target(com.xgj.aop.spring.advisor.aspectJ.function.* target.Class1)等同于* target(com.xgj.aop.spring.advisor.aspectJ.function* .target.Class1+)* * @author: Mr.Yang* * @date: 2017年9月5日 下午7:53:52*/@Aspect public class TargetAspect {@AfterReturning("target(com.xgj.aop.spring.advisor.aspectJ.function.target.IBussinessService)")public void crossCuttingCode() {System.out.println("some logic is here");} }

配置文件

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:aop="http://www.springframework.org/schema/aop"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aophttp://www.springframework.org/schema/aop/spring-aop.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"><!-- (1)聲明Context命名空間以及Schema文件 (2)掃描類包以及應用注解定義的bean --> <context:component-scan base-package="com.xgj.aop.spring.advisor.aspectJ.function.target"/><!-- 基于@AspectJ切面的驅動器 --> <aop:aspectj-autoproxy proxy-target-class="true"/><!-- 使用了@AspectJ注解的切面類 --> <bean class="com.xgj.aop.spring.advisor.aspectJ.function.target.TargetAspect"/></beans>

測試類

package com.xgj.aop.spring.advisor.aspectJ.function.target;import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext;public class TargetAspectTest {private ApplicationContext applicationContext;@Testpublic void test() {applicationContext = new ClassPathXmlApplicationContext("classpath:com/xgj/aop/spring/advisor/aspectJ/function/target/conf-target.xml");BussinessService bussinessService = applicationContext.getBean("bussinessService", BussinessService.class);// 織入增強bussinessService.doSomething();// 織入增強bussinessService.doAnother();} }

運行結果：

2017-09-05 20:37:52,147 INFO [main] (AbstractApplicationContext.java:583) - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@285211ef: startup date [Tue Sep 05 20:37:52 BOT 2017]; root of context hierarchy 2017-09-05 20:37:52,264 INFO [main] (XmlBeanDefinitionReader.java:317) - Loading XML bean definitions from class path resource [com/xgj/aop/spring/advisor/aspectJ/function/target/conf-target.xml] doSomething executed some logic is here doAnother executed some logic is here

---

this()

一般情況下，使用this()和target()來匹配定義切點，二者是等效的

• target(com.xgj.IBussiness)等價于 this(com.xgj.IBussiness)
• target(com.xgj.BussinessService)等價于this(com.xgj.BussinessService)

二者的區別體現在通過引介切面產生代理對象時的具體表現。

看個例子:

接口

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;public interface IBussinessService {String doBussiness(); }

實現類

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;import org.springframework.stereotype.Component;/*** * * @ClassName: BussinessService* * @Description: @Component標注的bean* * @author: Mr.Yang* * @date: 2017年9月5日 下午8:18:03*/@Component public class BussinessService implements IBussinessService {@Overridepublic String doBussiness() {System.out.println("doBussiness executed");return "success";}public String doAnother() {System.out.println("doAnother executed");return "success";} }

另外一個通過引介切面要實現的接口

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;public interface ITransportService {public void doTransport(); }

實現類

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;public class TransportService implements ITransportService {@Overridepublic void doTransport() {System.out.println("doTransport executed");}}

為Bussiness添加 ITransportService接口的切面

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.DeclareParents; import org.springframework.core.Ordered;/*** * * @ClassName: AddTransportForBussinessAspect* * @Description: 為Bussiness添加 ITransportService接口的切面* * @author: Mr.Yang* * @date: 2017年9月5日 下午9:18:50*/@Aspect public class AddTransportForBussinessAspect implements Ordered {// (1)value 為BussinessService添加接口實現, (2)defaultImpl要添加的接口的默認的接口實現類@DeclareParents(value = "com.xgj.aop.spring.advisor.aspectJ.function.thisFun.BussinessService", defaultImpl = TransportService.class)public ITransportService iTransportService; // (3) 要實現的目標接口@Overridepublic int getOrder() {return 2;}}

橫切邏輯切面

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.Aspect; import org.springframework.core.Ordered;/*** * * @ClassName: ThisAspect* * @Description: @Aspectn標注的切面* * * @author: Mr.Yang* * @date: 2017年9月5日 下午8:50:26*/@Aspect public class ThisAspect implements Ordered {// 織入任何運行期對象為ITransportService的Bean中@AfterReturning("this(com.xgj.aop.spring.advisor.aspectJ.function.thisFun.ITransportService)")public void corssCuttingCode() {System.out.println("some logic is here \n ");}@Overridepublic int getOrder() {return 1;} }

配置文件

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:aop="http://www.springframework.org/schema/aop"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aophttp://www.springframework.org/schema/aop/spring-aop.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"><!-- (1)聲明Context命名空間以及Schema文件 (2)掃描類包以及應用注解定義的bean --> <context:component-scan base-package="com.xgj.aop.spring.advisor.aspectJ.function.thisFun"/><!-- 基于@AspectJ切面的驅動器 --> <aop:aspectj-autoproxy proxy-target-class="true"/><!-- 使用了@AspectJ注解的切面類 --> <bean class="com.xgj.aop.spring.advisor.aspectJ.function.thisFun.ThisAspect"/> <bean class="com.xgj.aop.spring.advisor.aspectJ.function.thisFun.AddTransportForBussinessAspect"/></beans>

測試類

package com.xgj.aop.spring.advisor.aspectJ.function.thisFun;import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext;public class ThisAspectTest {private ApplicationContext applicationContext;@Testpublic void test() {applicationContext = new ClassPathXmlApplicationContext("classpath:com/xgj/aop/spring/advisor/aspectJ/function/thisFun/conf-this.xml");BussinessService bussinessService = (BussinessService) applicationContext.getBean("bussinessService");// 匹配 thisbussinessService.doBussiness();// 匹配 thisbussinessService.doAnother();// 匹配 this((ITransportService) bussinessService).doTransport();} }

運行結果

2017-09-05 22:24:03,301 INFO [main] (AbstractApplicationContext.java:583) - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@24177697: startup date [Tue Sep 05 22:24:03 BOT 2017]; root of context hierarchy 2017-09-05 22:24:03,397 INFO [main] (XmlBeanDefinitionReader.java:317) - Loading XML bean definitions from class path resource [com/xgj/aop/spring/advisor/aspectJ/function/thisFun/conf-this.xml] doBussiness executed some logic is here doAnother executed some logic is here doTransport executed some logic is here

如果有多個切面，注意多切面織入的順序，如果不加織入的順序， doTransport 方法的切面無法織入。

可見代理對象的方法都織入了this()函數定義的切面。

總結

以上是生活随笔為你收集整理的Spring-AOP @AspectJ切点函数之target()和this()的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。