Spring AOP aop:after 运行早期

Question

我最近一直在一个非常简单的应用程序上尝试 Spring 的 AOP 功能，但我坚持使用运行在专有时间调用该方法，即定义在section 应该运行在

中定义的方法之后

在我的代码中，main 方法之前和运行中定义的方法。当然是正常的，但后面的就不正常了。

预期的输出应该是：

HERE IS THE AOP BEFORE

From App ran 5k

HERE IS THE AOP After

我当前的输出是：

HERE IS THE AOP BEFORE

HERE IS THE AOP After

From App ran 5k

知道为什么吗？

Pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>springDemo</groupId>
<artifactId>FirstSpringDemo</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>FirstSpringDemo</name>
<url>http://maven.apache.org</url>
<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
    <sourceDirectory>src</sourceDirectory>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>
<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>4.3.1.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>4.3.1.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.3.1.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>4.3.1.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
    <dependency>
        <groupId>cglib</groupId>
        <artifactId>cglib</artifactId>
        <version>2.2</version>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.6.11</version>
    </dependency>
</dependencies>
</project>

我的主要 class，名为应用程序：

package main.java.springDemo;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App {
public static void main(String[] args) {

    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

    Coach trackCoach = context.getBean("myTrackCoach", Coach.class);

    System.out.println(" From App " + trackCoach.getDailyWorkout());


}
}

TrackerCoach.java

package main.java.springDemo;

public class TrackCoach implements Coach {
@Override
public String getDailyWorkout() {
    return "Go and run 5k";
}
}

SayAOP.java

package main.java.springDemo;


public class SayAOP {

   public void shoutAOPBefore() {

    System.out.println("HERE IS THE AOP BEFORE");
}

public void shoutAOPAfter(){

    System.out.println("HERE IS THE AOP After");
}

}

Coach.java

package main.java.springDemo;

public interface Coach {
    String getDailyWorkout();

}

applicationContext.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:context="http://www.springframework.org/schema/context"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

<!-- Define your beans here -->


<aop:config>

    <aop:aspect id="aop" ref="SayAOP">

        <aop:pointcut id="pid" expression="execution(* main.java.springDemo.Coach.getDailyWorkout(..))"/>

        <aop:before pointcut-ref="pid" method="shoutAOPBefore"/>
        <aop:after pointcut-ref="pid" method="shoutAOPAfter"/>
    </aop:aspect>

</aop:config>

<bean id="myTrackCoach"
      class="main.java.springDemo.TrackCoach">

</bean>

<bean id="SayAOP"
      class="main.java.springDemo.SayAOP">
</bean>

</beans>

Answer 1

那是因为 trackCoach.getDailyWorkout() 被称为 System.out.println 参数，所以 before 首先被调用，然后是 trackCoach.getDailyWorkout() ，然后是 System.out 最后。尝试例如：

public class TrackCoach implements Coach {
    @Override
    public String getDailyWorkout() {
        System.out.println("Go and run 5k");
        return "Go and run 5k";
    }
}

你会看到发生了什么。

Spring AOP aop:after 运行 早期

Spring AOP aop:after running early

java

aop

spring

spring-aop

maven

Spring AOP aop:after 运行早期