Day 93

_Spring技术–AOP通知获取数据

1. 获取切入点方法的参数：
   • JoinPoint：适用于前置、后置、返回后、抛出异常后通知
   • ProceedJoint：适用于环绕通知
2. 获取切入点方法返回值
   • 返回后通知
   • 环绕通知
3. 获取切入点方法运行异常信息
   • 抛出异常通知
   • 环绕通知

_Spring技术–AOP通知获取数据–@Before & @After

1. 如图所示，在业务层的实现类BookService中有两个方法：runBefore() 和 runAfter() :

2. 然后再aop包中配置AOP的增强程序：

   • package com.Alvis.aop;
     
     import org.aspectj.lang.JoinPoint;
     import org.aspectj.lang.ProceedingJoinPoint;
     import org.aspectj.lang.annotation.*;
     import org.springframework.stereotype.Component;
     
     import java.util.Arrays;
     
     @Component
     @Aspect
     public class MyAdvice {
         // 描述切面方法
         @Pointcut("execution(* com.Alvis.service.BookService.*(..))")
         public void servicePt() {}
     
     
     //    @Before("MyAdvice.servicePt()")
         public void before(JoinPoint joinPoint) {
             Object[] args = joinPoint.getArgs();
             System.out.println("before ...It has been executed");
             System.out.println(Arrays.toString(args));
         }
     
     //    @After("MyAdvice.servicePt()")
         public void after(JoinPoint joinPoint) {
             Object[] args = joinPoint.getArgs();
             System.out.println("After ...It has been executed");
             System.out.println(Arrays.toString(args));
         }
     
     
         @Around("MyAdvice.servicePt()")
         public Object around(ProceedingJoinPoint pjp) throws Throwable {
             Object[] args = pjp.getArgs();
             System.out.println("Around ...It has been executed");
     
             // 可以在此修改源方法传入的参数值
             args[0] = 1000;
             System.out.println(Arrays.toString(args));
             Object ret = pjp.proceed(args);
             return ret;
         }
     }
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   • 

   • 在test文件中编写BookServiceTest类测试方法：

     • package com.Alvis.service;
       
       import com.Alvis.config.SpringConfig;
       import org.junit.Test;
       import org.junit.runner.RunWith;
       import org.springframework.context.ApplicationContext;
       import org.springframework.context.annotation.AnnotationConfigApplicationContext;
       import org.springframework.test.context.ContextConfiguration;
       import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
       
       
       // 设定类运行器
       @RunWith(SpringJUnit4ClassRunner.class)
       @ContextConfiguration(classes = SpringConfig.class)
       
       
       public class ServiceTest {
           private BookService bookService;
       
           @Test
           public void testBookServiceBefore() {
               ApplicationContext apx = new AnnotationConfigApplicationContext(SpringConfig.class);
               BookService bookService = apx.getBean(BookService.class);
               bookService.runBefore(90);
           }
       
           @Test
           public void testBookServiceAfter() {
               ApplicationContext apx = new AnnotationConfigApplicationContext(SpringConfig.class);
               BookService bookService = apx.getBean(BookService.class);
               bookService.runAfter(100);
           }
       
           @Test
           public void testBookServiceAround() {
               ApplicationContext apx = new AnnotationConfigApplicationContext(SpringConfig.class);
               BookService bookService = apx.getBean(BookService.class);
               bookService.runAround(0 , "张三");
           }
       }
       ================================================
       before ...It has been executed
       [90]
       this is runBefore...
       age is ...90
       
       进程已结束,退出代码0
       ================================================
       
       this is runAfter
       age is ...100
       After ...It has been executed
       [100]
       
       进程已结束,退出代码0
       
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_Spring技术–AOP–通知获取数据–@Around

1. @Around可以对源方法传入的参数进行调整

2. 在aop包中的MyAdvice类中的@Around方法描述如图所示：

3. 最后在test文件的BookServiceTest类中对AOP@Around通知修改源方法的参数值作测试

   • 源方法中传入的参数值如图所示：

   •     @Test
         public void testBookServiceAround() {
             ApplicationContext apx = new AnnotationConfigApplicationContext(SpringConfig.class);
             BookService bookService = apx.getBean(BookService.class);
             bookService.runAround(0 , "张三");
         }
     =======================================
     Around ...It has been executed
     [1000, 张三]
     this is runAround
     name = 张三  age is ...1000
     
     进程已结束,退出代码0
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   •