@spring“Manager”类中的自动连线注释

Question

我对spring中的@Autowired注释有问题。我有一个RestController类：

 package sptool.controller;

    @org.springframework.web.bind.annotation.RestController
public class CategoryController {

    @Autowired
    private CategoryManager categoryManager;

  //Methods
}

接口：

package sptool.managers;
public interface CategoryManager {
    public void save(Category category);
    public Category getCategoryById(int id);
    public List<Category> getAllCategories();
    public void updateCategory(Category category);
    public void deleteCategory(int id);
}

CategoryManagerImpl类：

package sptool.managers;
@Service
public class CategoryManagerImpl implements CategoryManager {

    @Autowired
    private CategoryDao categoryDao;
   //Methods
}

每次编译代码时，我都会遇到一个异常：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'categoryController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private sptool.managers.CategoryManager sptool.controller.CategoryController.categoryManager; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sptool.managers.CategoryManager] 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)}

Bun当我创建ApplicationContext并尝试获取categoryManagerImpl bean时，没有问题：

applicationContext = new AnnotationConfigApplicationContext(ConfigurationClass.class);
application.getBean("controllerManagerImpl"); //<< works 

有人知道哪里会有问题吗？

谢谢

添加了

配置类：

package sptool.config;

@Configuration
@ComponentScan({"sptool.managers", "sptool.dao", "sptool.controller", "sptool.model"})
@PropertySource({"classpath:application.properties"})
public class ConfigurationClass {

    @Autowired
    private Environment env;

    @Bean(name = "dataSource")
    public DriverManagerDataSource dataSource()
    {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
        dataSource.setUrl(env.getProperty("spring.datasource.url"));
        dataSource.setUsername(env.getProperty("spring.datasource.username"));
        dataSource.setPassword(env.getProperty("spring.datasource.password"));

        return dataSource;
    }

    @Bean(name = "sessionFactory")
    public LocalSessionFactoryBean sessionFactoryBean()
    {
        LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        sessionFactory.setPackagesToScan(env.getProperty("annotated.packages"));
        sessionFactory.setPackagesToScan( new String[] {"sprool.model"});
        sessionFactory.setHibernateProperties(hibernateProperties());

        return sessionFactory;
    }

    Properties hibernateProperties()
    {
        Properties properties = new Properties();
        properties.setProperty("hibernate.dialect", env.getProperty("spring.jooq.sql-dialect"));
        properties.setProperty("hibernate.show_sql", env.getProperty("show.sql"));
        properties.setProperty("hibernate.current_session_factory", env.getProperty("current.session.class"));
        properties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("spring.jpa.hibernate.ddl-auto"));

        return properties;
    }

    @Bean(name = "transactionManager")
    @Autowired
    public HibernateTransactionManager hibernateTransactionManager(SessionFactory sessionFactory)
    {
        HibernateTransactionManager txManager = new HibernateTransactionManager();
        txManager.setSessionFactory(sessionFactory);
        return txManager;
    }

}

堆栈跟踪：

 org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'categoryController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private sptool.managers.CategoryManager sptool.controller.CategoryController.categoryManager; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sptool.managers.CategoryManager] 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-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
        at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
        at sptool.controller.App.main(App.java:18) [classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
        at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) [idea_rt.jar:na]
    Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private sptool.managers.CategoryManager sptool.controller.CategoryController.categoryManager; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sptool.managers.CategoryManager] 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:573) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        ... 22 common frames omitted
    Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sptool.managers.CategoryManager] 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:1373) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
        ... 24 common frames omitted

Answer 1

由于此CategoryManagerImpl是用@Service注释的，因此不需要在spring servlet中再次声明它（如

applicationContext = new AnnotationConfigApplicationContext(ConfigurationClass.class);
application.getBean("controllerManagerImpl"); //<< works

最后，CategoryManager将被CategoryManagerImpl很好地注入。

Answer 2

尝试执行以下更改：

@Service
public interface CategoryManager {
    public void save(Category category);
    public Category getCategoryById(int id);
    public List<Category> getAllCategories();
    public void updateCategory(Category category);
    public void deleteCategory(int id);
}
@Component
public class CategoryManagerImpl implements CategoryManager {

    @Autowired
    private CategoryDao categoryDao;
   //Methods
}

您面临的问题是，spring无法识别bean CategoryManager，因为它没有使用服务/组件进行注释。这样做应该可以解决这个问题。

仅供参考，如果您有一个以上的类别管理器实现，我建议您使用@Component（value="myComponent"）为实现包含标识符

如果有帮助，请告诉我