java - SpringBoot 使用 MongoDB 实现通用 DAO

Question

我想使用 mongodb 实现一个通用的 DAO。我的观点不是只创建一个存储库而创建多个存储库。使代码实用且客观。我能够创建多个类并进行交互，但出现错误。

我的代码:

Dao.java

public interface Dao<T, ID extends Serializable> extends MongoRepository<T, ID>{


}

NewsDao.java

public interface NewsDao extends Dao<News, Long> {


}

AbstractService.java

public abstract class AbstractService<T, ID extends Serializable> implements
        Service<T, ID> {

    protected final Logger logger = LoggerFactory.getLogger(getClass());
    protected Dao<T, ID> dao;

    public AbstractService(Dao<T, ID> dao) {
        this.dao = dao;
    }

    @Override
    public T save(T entity) {
        this.logger.debug("Create a new {} with information: {}", entity.getClass(),
                entity.toString());
        return this.dao.save(entity);
    }

}

NewsService.java

@Service
public class NewsService extends AbstractService<News, Long> {

    @Autowired
    public NewsService(NewsDao moduleDao) {
        super(moduleDao);
    }

}

服务.java

public interface Service<T, ID extends Serializable> {

     T save(T entity);

}

NewsController.java

@RestController
@RequestMapping("/news")
public class NewsController {

    private final NewsService newsService;

    @Autowired
    public NewsController(NewsService newsService) {
        this.newsService = newsService;
    }

    @RequestMapping(method = RequestMethod.GET)
    public void save(){
        newsService.save(new News("elo", "kot", "cos"));
    }
}

错误:

2016-03-02 19:04:11.509  WARN 4476 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'newsService' defined in file [C:\Users\Lukasz\IdeaProjects\NewsSystem_REST\build\classes\main\com\newssystem\lab\dao\NewsService.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [com.newssystem.lab.dao.NewsDao]: : No qualifying bean of type [com.newssystem.lab.dao.NewsDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.newssystem.lab.dao.NewsDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
2016-03-02 19:04:11.516  INFO 4476 --- [           main] o.apache.catalina.core.StandardService   : Stopping service Tomcat
2016-03-02 19:04:11.538 ERROR 4476 --- [           main] o.s.boot.SpringApplication               : Application startup failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'newsService' defined in file [C:\Users\Lukasz\IdeaProjects\NewsSystem_REST\build\classes\main\com\newssystem\lab\dao\NewsService.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [com.newssystem.lab.dao.NewsDao]: : No qualifying bean of type [com.newssystem.lab.dao.NewsDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.newssystem.lab.dao.NewsDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:185) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[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$1.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.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at com.newssystem.lab.NewsSystemApplication.main(NewsSystemApplication.java:24) [main/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_25]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_25]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_25]
    at java.lang.reflect.Method.invoke(Method.java:483) ~[na:1.8.0_25]
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) [idea_rt.jar:na]
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.newssystem.lab.dao.NewsDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119) ~[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.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:813) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) ~[spring-beans-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    ... 24 common frames omitted

我走的路对吗？

Answer 1

试试这个

Spring data 无法找到您的 mongo 包存储库告诉 spring 你的存储库位置

你应该使用

@EnableMongoRepositories(basePackages="com.newssystem.lab.dao")

在您的 SpringBootCofiguration 文件中