Java SpringBoot一个服务，多个类

我使用SpringBoot和MongoDB创建了带有注释的简单新闻系统。我想把重点放在代码质量上。我使用泛型创建服务来保存类中的数据

我的代码：

java

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


}

---

您必须使用限定符注释来定义哪个bean将被注入到您的服务中。在Spring上，一个接口可以有许多实现，但是如果这些实现都没有定义主注释，Spring就不知道自动选择哪个实现

@Autowired
@Qualifier("bean-name")

---

您必须使用限定符注释来定义哪个bean将被注入到您的服务中。在Spring上，一个接口可以有许多实现，但是如果这些实现都没有定义主注释，Spring就不知道自动选择哪个实现

@Autowired
@Qualifier("bean-name")

---

我同意：

@Autowired@Qualifier（“DaoService”）私有最终DaoService新闻服务

但仍然不起作用这个名称是为bean类定义的吗？你的意思是什么？正如你在日志文件中看到的，有2个DAO，所以你必须使用@Qualifier通知你的服务哪一个应该被感染，例如@Qualifier（“newsDao”）I：

@Autowired@Qualifier（“DaoService”）私人新闻服务但仍然不起作用这个名称是为bean类定义的吗？你的意思是什么？正如你在日志文件中看到的，有2个DAO，所以你必须使用@Qualifier例如@Qualifier（“newsDao”）通知你的服务哪一个应该被感染
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);
    }

}

@Repository
public interface CommentDao extends Dao<Comment, Long> {

}

@Repository
public interface NewsDao extends Dao<News, Long> {

}

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

    private final DaoService<News> newsService;
    private final DaoService<Comment> commentDaoService;


    public NewsController(DaoService<News> newsService, DaoService<Comment> commentDaoService) {
        this.newsService = newsService;
        this.commentDaoService = commentDaoService;
    }

    @RequestMapping(method = RequestMethod.GET)
    public void save(){
        newsService.save(new News("elo","a","c"));
        commentDaoService.save(new Comment("iss","we"));
    }
}

2016-03-02 23:22:30.265  WARN 6100 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'daoService' defined in file [C:\Users\Lukasz\IdeaProjects\NewsSystem_REST\build\classes\main\com\newssystem\lab\dao\DaoService.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [com.newssystem.lab.dao.Dao]: : No qualifying bean of type [com.newssystem.lab.dao.Dao] is defined: expected single matching bean but found 2: newsDao,commentDao; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.newssystem.lab.dao.Dao] is defined: expected single matching bean but found 2: newsDao,commentDao
2016-03-02 23:22:30.273  INFO 6100 --- [           main] o.apache.catalina.core.StandardService   : Stopping service Tomcat
2016-03-02 23:22:30.296 ERROR 6100 --- [           main] o.s.boot.SpringApplication               : Application startup failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'daoService' defined in file [C:\Users\Lukasz\IdeaProjects\NewsSystem_REST\build\classes\main\com\newssystem\lab\dao\DaoService.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [com.newssystem.lab.dao.Dao]: : No qualifying bean of type [com.newssystem.lab.dao.Dao] is defined: expected single matching bean but found 2: newsDao,commentDao; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.newssystem.lab.dao.Dao] is defined: expected single matching bean but found 2: newsDao,commentDao
    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:18) [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.NoUniqueBeanDefinitionException: No qualifying bean of type [com.newssystem.lab.dao.Dao] is defined: expected single matching bean but found 2: newsDao,commentDao
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1126) ~[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

@Autowired
@Qualifier("bean-name")