Question

我有两个项目：user-services和datamodel-dao。在用户服务中，我试图从datamodel-dao获取UserDao，但是我收到了这个错误：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService' defined in file [/home/khliwa/projects/moza-core-services/moza-user-services/target/classes/pl/moza/user/service/UserService.class]: Bean instantiation via constructor failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [pl.moza.user.service.UserService]: Constructor threw exception; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [pl.moza.dao.UserInterface] is defined
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:275) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:838) ~[spring-context-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537) ~[spring-context-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) [spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.doRun(SpringApplication.java:347) [spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:295) [spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1112) [spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1101) [spring-boot-1.3.0.RELEASE.jar:1.3.0.RELEASE]
    at pl.moza.user.UserApplication.main(UserApplication.java:18) [classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [pl.moza.user.service.UserService]: Constructor threw exception; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [pl.moza.dao.UserInterface] is defined
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:122) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:267) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    ... 18 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [pl.moza.dao.UserInterface] is defined
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:372) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:332) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1063) ~[spring-context-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    at pl.moza.user.service.UserService.<init>(UserService.java:28) ~[classes/:na]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_131]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_131]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_131]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_131]
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147) ~[spring-beans-4.2.3.RELEASE.jar:4.2.3.RELEASE]
    ... 20 common frames omitted

来自数据服务的类服务，我试图去做dao。

@Service
public class UserService {
    UserDao userDao;

    @Autowired
    public UserService(ApplicationContext ctx) {
        userDao = (UserDao) ctx.getBean(UserDao.class);
    }
    //methods

应用：

@Controller
@SpringBootApplication
@EnableAsync
@ComponentScan(basePackages = {"pl.moza.user.*", "pl.moza.dao"})
public class UserApplication extends WebMvcConfigurerAdapter {

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

来自datamodel-dao：

public class UserDao implements Serializable{
    @Inject
    UserInterface userInterface;
//methods
}

UserInterface是MyBatis界面，如下所示：

public interface UserInterface {

    public UserApp getUserByLogin(String login) throws Exception;
    //more methods

如果我理解正确，问题在于接线接口。我该如何解决这个问题（如果可能的话 - 不改变datamodel-dao）？

Answer 1

在这里，您没有使用@Component或UserDao的任何等效xml配置，那么spring容器（应用程序上下文）将不会创建任何bean，然后spring容器不负责创建或管理实例它。另一件事是我不明白你为@Inject使用userInterface的原因???相反，您可以在UserDao和@Autowired UserService上实现它。

@Repository("userDao")
public class UserDao implements UserInterface {
    //methods
}


@Service
public class UserService {

    @Autowired
    @Qualifier("userDao")
    UserDao userDao;

    //methods
}

确保您已在datamodel-dao中添加了user-services的依赖关系，@ComponentScan(basePackages = {"pl.moza.user.*", "pl.moza.dao"})涵盖了实际所需的路径。

无法从外部项目中获取bean

1 个答案: