考慮您的配置定義類型「服務」的豆[春季啓動]

Question

我得到的錯誤，當我運行的主類。

錯誤：

Action: 
Consider defining a bean of type 'seconds47.service.TopicService' in your configuration. 

Description: 
Field topicService in seconds47.restAPI.topics required a bean of type 'seconds47.service.TopicService' that could not be found 

TopicService接口：

public interface TopicService { 

    TopicBean findById(long id); 

    TopicBean findByName(String name); 

    void saveTopic(TopicBean topicBean); 

    void updateTopic(TopicBean topicBean); 

    void deleteTopicById(long id); 

    List<TopicBean> findAllTopics(); 

    void deleteAllTopics(); 

    public boolean isTopicExist(TopicBean topicBean); 
} 

控制器：

@RestController 
public class topics { 

    @Autowired 
    private TopicService topicService; 

    @RequestMapping(path = "/new_topic2", method = RequestMethod.GET) 
    public void new_topic() throws Exception { 
     System.out.println("new topic JAVA2"); 
    } 
} 

實現類：

public class TopicServiceImplementation implements TopicService { 

    @Autowired 
    private TopicService topicService; 

    @Autowired 
    private TopicRepository topicRepository; 

    @Override 
    public TopicBean findById(long id) { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public TopicBean findByName(String name) { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public void saveTopic(TopicBean topicBean) { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public void updateTopic(TopicBean topicBean) { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public void deleteTopicById(long id) { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public List<TopicBean> findAllTopics() { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public void deleteAllTopics() { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 

    @Override 
    public boolean isTopicExist(TopicBean topicBean) { 
     throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. 
    } 
} 

其餘的類也被定義。儘管在主類中宣佈了componentScan，但我不知道爲什麼投擲。

主要類：

@SpringBootApplication(exclude = {SecurityAutoConfiguration.class }) 
@ComponentScan(basePackages = {"seconds47"}) 
@EnableJpaRepositories("seconds47.repository") 
public class Application { 

    public static void main(String[] args) { 
     SpringApplication.run(Application.class, args); 
    } 
} 

我有我的包是這樣的：

seconds47 
seconds47.beans 
seconds47.config 
seconds47.repository 
seconds47.restAPI 
seconds47.service 

Answer 1

一個類必須具有@Component註釋或派生（例如@Service,@Repository等）才能被組件掃描識別爲Spring bean。所以如果你將@Component添加到課程中，它應該可以解決你的問題。

Answer 2

您試圖在自身注入一個bean。這顯然不起作用。

TopicServiceImplementation實現TopicService。該類嘗試自動裝入（通過字段！）一個`TopicService。所以你基本上要求上下文注入自己。

它看起來像你編輯的錯誤消息的內容：Field topicService in seconds47.restAPI.topics是不是一類。如果您需要隱藏敏感信息，請小心，因爲這會讓別人更難以幫助您。

回到實際問題，它看起來像注射TopicService本身就在你身邊一個小故障。

Answer 3

由於TopicService是Service類，因此您應該使用@Service對其進行註釋，以便Spring爲您自動裝配此Bean。像這樣：

@Service 
public class TopicServiceImplementation implements TopicService { 
    ... 
} 

這將解決您的問題。

Answer 4

必須更新您的

scanBasePackages = { "com.exm.java" } 

的路徑添加到您的服務（與@Service註解之後）