Question

我一直在尝试开发一个演示@Before Annotation的小应用程序，但是它不起作用

pom.xml

kotlin version : 1.2.71
// dagger
implementation 'com.google.dagger:dagger-android:2.16'
implementation 'com.google.dagger:dagger-android-support:2.16'
kapt "com.google.dagger:dagger-compiler:2.16"
kapt "com.google.dagger:dagger-android-processor:2.16"

AccoutDAO.java文件是

<?xml version="1.0" encoding="UTF-8"?>
<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>aopdemo</groupId>
<artifactId>aopdemo</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>5.0.6.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>5.0.6.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <version>5.0.6.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.6.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>5.0.6.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjrt</artifactId>
        <version>1.6.11</version>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.9.0</version>
    </dependency>
</dependencies>

Aspect配置文件为

   package org.java.aop.dao;

import org.springframework.stereotype.Component;
@Component
public class AccoutDAO {
    public void addAccount()
    {
        System.out.println("Adding account"+getClass());
    }
}

spring配置文件（spring-config.xml）是

   package org.java.aop.aspects;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class MyAspects {

    @Before("execution(public void addAccount())")
    public void display()
    {
        System.out.println("=====================>>CALLING Aspects");
    }
}

最后我的主要代码是

    <?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:mvc="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">
<bean id="accountDAO" class="org.java.aop.dao.AccoutDAO">
</bean>
<aop:aspectj-autoproxy/>

</beans>

我能够将输出显示为“ INFO：从类路径资源[spring-config.xml]加载XML bean定义。添加帐户类org.java.aop.dao.AccoutDAO 2018年11月22日2:06:14 org.springframework.context.support.AbstractApplicationContext doClose INFO：关闭org.springframework.context.support.ClassPathXmlApplicationContext@1ed6993a：启动日期[IST 2018年11月22日星期二02:06:14]；上下文层次结构的根”

但是我无法获取@Before Annotation的输出。请告诉我这段代码有什么问题

Answer 1

通过在spring-config.xml中添加组件扫描来解决上述问题

 <?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:mvc="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       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">
<bean id="accountDAO" class="org.java.aop.dao.AccoutDAO">
</bean>
<aop:aspectj-autoproxy/>
<context:component-scan base-package="org.java.aop"/>
</beans>

@Before建议注释未在Spring应用程序中应用

1 个答案: