java - 如何解决循环依赖？

我无法在以下代码片段中解决循环依赖关系：

错误

Jun 19, 2018 3:50:40 PM org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet [supportCenter] in web application [/SupportCenter] threw load() exception
org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'userEmployeeDetailByUserId': Requested bean is currently in creation: Is there an unresolvable circular reference?

码

@Configuration
//@Import(MasterService.class)
public class ApplicationConfiguration {

    private MasterService masterService;

    public ApplicationConfiguration() {}

    @Autowired
    public void setMasterService(MasterService masterService) {
        this.masterService = masterService;
    }

    @Bean(name="userEmployeeDetailByUserId")
    public Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId() {
        final Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId = new HashMap<Integer, UserEmployeeDetail>();
        List<UserEmployeeDetail> userEmployeeDetails = this.masterService.getUserEmployeeDetails();
        for ( UserEmployeeDetail userEmployeeDetail : userEmployeeDetails ) {
            userEmployeeDetailByUserId.put(userEmployeeDetail.getUserId(), userEmployeeDetail);
        }
        return userEmployeeDetailByUserId;
    }
}

MasterServiceImpl

@Service
public class MasterServiceImpl implements MasterService {//, ApplicationContextAware, InitializingBean

    private static final Logger LOGGER = LogManager.getLogger(MasterServiceImpl.class);

    @Autowired
    private MasterDao masterDao;

    @Resource(name="userEmployeeDetailByUserId")
//  @Autowired
//  @Qualifier(value="userEmployeeDetailByUserId")
    private Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId;

//  private ApplicationContext applicationContext;
//

    public MasterServiceImpl() {}
//  public MasterServiceImpl(@Lazy Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId) {
//      this.userEmployeeDetailByUserId = userEmployeeDetailByUserId;
//  }



//  @Override
//  public void setApplicationContext(ApplicationContext applicationContext)
//          throws BeansException {
//      this.applicationContext = applicationContext;
//
//  }
//
//  @SuppressWarnings("unchecked")
//  @Override
//  public void afterPropertiesSet() throws Exception {
//      this.userEmployeeDetailByUserId = (Map<Integer, UserEmployeeDetail>)
//                          applicationContext.getBean("userEmployeeDetailByUserId");
//  }

    public void setMasterDao(MasterDao masterDao) {
        this.masterDao = masterDao;
    }


//  public void setUserEmployeeDetailByUserId(Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId) {
//      this.userEmployeeDetailByUserId = userEmployeeDetailByUserId;
//  }


    @Override
    public List<UserEmployeeDetail> getUserEmployeeDetails() {
        try {
            return this.masterDao.getUserEmployeeDetails();
        } catch (Exception e) {
            e.printStackTrace();
            LOGGER.error("Message     :- "+e.getMessage());
        LOGGER.error("Root Cause  :- "+e.getCause());
        LOGGER.error("                 ************************************************************");
        return new ArrayList<>();
        }
    }
}

代码有什么问题？
我应该重新设计我的组件吗？

最佳答案

将getUserEmployeeDetails移至新的Service并使MasterServiceImpl和Bean userEmployeeDetailByUserId使用此新服务：

@Service
class NewService {

    @Autowired
    private MasterDao masterDao;

    @Override
    public List<UserEmployeeDetail> getUserEmployeeDetails() {
        try {
            return this.masterDao.getUserEmployeeDetails();
        } catch (Exception e) {
            e.printStackTrace();
            LOGGER.error("Message     :- "+e.getMessage());
        LOGGER.error("Root Cause  :- "+e.getCause());
        LOGGER.error("                 ************************************************************");
        return new ArrayList<>();
        }
    }
}

类别MasterServiceImpl：

@Service
public class MasterServiceImpl implements MasterService {//, ApplicationContextAware, InitializingBean

    @Resource(name="userEmployeeDetailByUserId")
    private Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId;

和ApplicationConfiguration：

@Configuration
//@Import(MasterService.class)
public class ApplicationConfiguration {

    private NewService newService;

    public ApplicationConfiguration() {}

    @Autowired
    public void setNewService(NewService newService) {
        this.newService= newService;
    }

    @Bean(name="userEmployeeDetailByUserId")
    public Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId() {
        final Map<Integer, UserEmployeeDetail> userEmployeeDetailByUserId = new HashMap<Integer, UserEmployeeDetail>();
        List<UserEmployeeDetail> userEmployeeDetails = this.newService.getUserEmployeeDetails();
        for ( UserEmployeeDetail userEmployeeDetail : userEmployeeDetails ) {
            userEmployeeDetailByUserId.put(userEmployeeDetail.getUserId(), userEmployeeDetail);
        }
        return userEmployeeDetailByUserId;
    }
}

关于java - 如何解决循环依赖？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/50926481/