Question

我喜欢春天，我喜欢那些注释，为我节省了很多时间。但它也让我头脑发热。那么有人可以向我解释@Autowired plz吗？

我遵循了一些教程，这是我得到的：

SEVERE: Exception sending context initialized event to listener instance of class    org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'registerController': 
Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.isad.dao.UserAccountDAO 
com.isad.controller.RegisterController.userAccount; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.isad.dao.UserAccountDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

我的Pojo：

private int id;
private String username;
private String email;
private String password;

我的道：

@Repository
@Transactional
public class UserAccountDAOImpl implements UserAccountDAO{
@Autowired
private SessionFactory sessionFactory;
public UserAccount getById(int id) {
    return (UserAccount) sessionFactory.getCurrentSession()
                                    .get(UserAccount.class, id);
}
public int save(UserAccount aUser) {
    return (Integer)sessionFactory.getCurrentSession().save(aUser);
}
}

我的控制器：

@Autowired
private UserAccountDAO userAccount;
@Autowired
private UserAccountFormValidator validator;

@RequestMapping(value="register", method=RequestMethod.POST)
public String registerPage(@ModelAttribute("newUserAccount") UserAccount aUser,
                        BindingResult result) {
    System.out.println("inside register post");
    validator.validate(aUser, result);
    if( result.hasErrors()) {
        return "register";
    }
    userAccount.save( aUser );
    return "../../index";
}

UserAccountFormValidator：

@Component("useraccountFormValidator")
public class UserAccountFormValidator implements Validator{
@Override
public boolean supports(Class<?> arg0) {
    return UserAccount.class.isAssignableFrom( arg0 );
}
@Override
public void validate(Object arg0, Errors arg1) {
    ValidationUtils.rejectIfEmptyOrWhitespace(arg1, "name", "required");
}
}

Answer 1

可能没有针对Spring bean扫描com.isad.dao的包UserAccountDAOImpl。检查你的Spring配置。

Answer 2

确保您的spring配置文件提供：

<context:component-scan base-package="com.isad"/>

如何正确连接或自动思考？

2 个答案: