Spring Boot多模块Maven项目@Autowired不起作用



这真的很奇怪。我开始我的Spring Boot项目是作为一个单一的maven项目,所有的工作都很完美。它基本上是一个Spring MVC应用程序,具有安全性和邮件功能。

然后,当我看到一些组件,如服务,存储库,模型将被一个独立的应用程序重用时,我决定将maven项目拆分为子模块。

突然没有自动布线开始工作。经过一番调查,我发现我需要显式地将这些包放在独立应用程序的应用程序中:

@ComponentScan (basePackages={"service"})
@EnableJpaRepositories(basePackages={"repository"})
@EnableAutoConfiguration
@EntityScan(basePackages={"model"})

好的,在那之后,我的自定义类开始自动连接。但是另一个问题出现了:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.mail.javamail.JavaMailSender service.impl.UserServiceImpl.mailSender; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.mail.javamail.JavaMailSender] 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)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1210)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:957)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:946)
    at com.me.newsaggregator.rsscollector.RsscollectorApplication.main(RsscollectorApplication.java:18)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.mail.javamail.JavaMailSender service.impl.UserServiceImpl.mailSender; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.mail.javamail.JavaMailSender] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:561)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
    ... 16 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.mail.javamail.JavaMailSender] 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.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1301)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1047)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:942)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533)

所以看起来标准包不再自动连接了。这个独立应用程序的Pom.xml:

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-mail</artifactId>
    </dependency>
    <dependency>
        <groupId>com.sun.mail</groupId>
        <artifactId>javax.mail</artifactId>
        <version>1.5.4</version>
    </dependency>

请帮。

我终于让它工作了。除了添加上面提到的注释,我还必须:

  1. 将类MailConfiguration添加到独立驻留应用程序(com.my.newsaggregator.rsscollector)
  2. 添加独立应用程序库包(com.my.newsaggregator.rsscollector)到@ComponentScan

我的意思是:

package com.my.newsaggregator.rsscollector;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.orm.jpa.EntityScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
@ComponentScan (basePackages={"service","com.my.newsaggregator.rsscollector"})
@EnableJpaRepositories(basePackages={"repository"})
@EnableAutoConfiguration
@EntityScan(basePackages={"model"})
public class RsscollectorApplication {
    public static void main(String[] args) {
        SpringApplication.run(RsscollectorApplication.class, "--debug").close();
        System.out.println("done");
    }
}
顺便说一下,同样的情况也会发生在您的JUnit测试中。在我的情况下,我得到了一个关于Spring安全没有自动连接的错误。

一个非常简单的方法来解决这个问题:设置

scanBasePackages

到你的根包,对我来说是:org.umasuo,这样spring就可以扫描所有你需要扫描的类。

@SpringBootApplication(scanBasePackages = "you.root.package")
public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

实际上,我们可以看看弹簧是如何进行包扫描的,这样我们就可以更好地了解它了

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