在 Spring 中尝试将 Aspect 添加到 MongoTemplate 时出错

Question

我正在尝试以这种方式向 Spring 剩余数据中的 MongoTemplate Bean 添加方面：

Application.java

@SpringBootApplication
@ComponentScan(basePackages = {"config"})
public class Application {
    public static void main(String[] args) {
        ApplicationContext ctx = SpringApplication.run(Application.class, args);
    }
}

AspectConfig.java

@Configuration
@EnableAspectJAutoProxy
@ComponentScan(basePackages = {"aspect"})
public class AspectConfig {
}

MongAspect.java

@Component
@Aspect
public class MongoAspect {
    @AfterReturning("execution(* *.find(..)) && bean(mongoTemplate)")
    public void after(JoinPoint joinPoint) {
        String x = "aga";
    }
}

但我收到这样的错误：

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'designRepositoryImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: org.springframework.data.mongodb.core.MongoTemplate repository.design.DesignRepositoryImpl.mt; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.data.mongodb.core.MongoTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:296) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1192) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1116) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    ... 174 common frames omitted

代理 bean 无法自动装配是什么意思。

有什么办法可以解决这个问题吗？因为我需要拦截所有 MongoTemplate.find 调用。

Answer 1

class MongoTemplate 实现了两个接口，MongoOperations 和 ApplicationContextAware。只要您添加方面，Spring 就会为此 class 创建一个代理，它将执行方面代码。默认情况下，如果 class 实现了一个接口，Spring 将使用 JDK 代理，它只实现这些接口，而不扩展 class。所以代理，也就是 Spring bean，没有类型 MongoTemplate，只有 MongoOperations.

使用以下注释中的属性，您告诉 Spring，它应该使用 CGLib 创建代理并且应该扩展 class，因此注入也适用于带有 [= 的字段13=]:

@EnableAspectJAutoProxy(proxyTargetClass=true)

在 Spring 中尝试将 Aspect 添加到 MongoTemplate 时出错

Error when trying to add Aspect to MongoTemplate in Spring

java

spring

spring-aop

spring-data

spring-mongo