UnsatisfiedDependencyException：创建名为“homeController”的 bean 时出错：通过字段“userDAO”表达的不满意依赖

Question

我正在尝试连接 eclipse spring maven 的后端和前端两个独立的项目。我为此添加了依赖项。但是当我在 Homecontroller.java 中写下验证凭证逻辑时，在服务器上运行后它显示了这个异常。请帮助解决它我已经尝试了很多方法，请提出建议。

主控制器.java

package com.yogesh.shoponlinefrontend.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Required;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

import com.yogesh.shoponlineback.dao.UserDAO;
import com.yogesh.shoponlineback.model.User;

@Controller
public class HomeController {


@Autowired
UserDAO userDAO;


@RequestMapping("/")
public String homePage() {
    System.out.println("Executing  the method homePage");
    return "home";
}

@RequestMapping("/login")
public ModelAndView showLoginPage() {

    ModelAndView mv = new ModelAndView("home");
    mv.addObject("msg", "You clicked login link");
    mv.addObject("showLoginPage", "true");
    return mv;
}

@RequestMapping("/register")
public ModelAndView showRegistrationPage() {
    ModelAndView mv = new ModelAndView("home");

    mv.addObject("msg", "You clicked Registration link ");

    mv.addObject("showRegistrationPage", "true");

    return mv;
}

@RequestMapping("/validate")
public ModelAndView validate(@RequestParam("id") String id, @RequestParam("password") String pwd) {
    System.out.println("In validate method");
    System.out.println("id: " + id);
    System.out.println("pwd: " + pwd);
    ModelAndView mv = new ModelAndView("home");

    if (userDAO.validate(id, pwd) != null) {
        mv.addObject("successMsg", "You logged in successfully");
    } else {
        mv.addObject("errorMsg", "Invalid Credentials..Please try again");
    }

    return mv;
}

}

UserDAO.java

package com.yogesh.shoponlineback.dao;

import java.util.List;

import com.yogesh.shoponlineback.model.User;

public interface UserDAO {

public List<User> list();

public User get(String username);

public User validate(String username, String password);

public boolean save(User user);

public boolean update(User user);
}

用户.java

package com.yogesh.shoponlineback.model;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.Max;
import javax.validation.constraints.Min;

import org.hibernate.validator.constraints.NotEmpty;
import org.springframework.stereotype.Component;

@Entity
//cha
@Table(name="USER")  
@Component
public class User {

@Id
private String username;

@NotEmpty(message = "please enter your name")
private String name;

@Min(5)
@Max(15)
private String password;
private String mobile;
private String role;

public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}


public String getMobile() {
    return mobile;
}

public void setMobile(String mobile) {
    this.mobile = mobile;
}

public String getRole() {
    return role;
}

public void setRole(String role) {
    this.role = role;
}

}

用户DAOImpl.java

package com.yogesh.shoponlineback.daoimpl;

import java.util.List;


import org.hibernate.Query;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.yogesh.shoponlineback.dao.UserDAO;
import com.yogesh.shoponlineback.model.User;

@Service
@Repository()
public class UserDAOImpl implements UserDAO {


@Autowired
UserDAO userDAO;

@Autowired
private SessionFactory sessionFactory;
public UserDAOImpl(SessionFactory sessionFactory) {
    this.sessionFactory = sessionFactory;
}

public UserDAOImpl() {
    // TODO Auto-generated constructor stub
}

@Transactional
public List<User> list() {
    String hql = "from User";
    Query query = sessionFactory.getCurrentSession().createQuery(hql);
    return query.list();
}

@Transactional
public User get(String username) {
    return (User) sessionFactory.getCurrentSession().get(User.class, username);
}

@Transactional
public  User validate(String username, String password) {
    String hql = "from User WHERE username ='" + username + "' and password='" + password + "'";
    Query query = sessionFactory.getCurrentSession().createQuery(hql);
    return (User)query.uniqueResult();
}

@Transactional
public boolean save(User user) {
    try {
        sessionFactory.getCurrentSession().save(user);
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }

    return true;
}

@Transactional
public boolean update(User user) {
    try {
        sessionFactory.getCurrentSession().update(user);
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }
    return true;
}

}

::::::::::::::::::::::::::::::异常跟踪:::::::::::::::::::: :::::::::::::::

INFO: FrameworkServlet 'dispatcher': initialization started
Jan 10, 2017 3:19:22 PM **org.springframework.web.context.support.AnnotationConfigWebApplicationContext prepareRefresh
INFO: Refreshing WebApplicationContext for namespace 'dispatcher-servlet': startup date [Tue Jan 10 15:19:22 IST 2017]; root of context hierarchy
Jan 10, 2017 3:19:22 PM org.springframework.web.context.support.AnnotationConfigWebApplicationContext loadBeanDefinitions
INFO: Registering annotated classes: [class com.yogesh.shoponlinefrontend.config.AppConfig]
Jan 10, 2017 3:19:23 PM org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor <init>
INFO: JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
Jan 10, 2017 3:19:23 PM org.springframework.web.context.support.AnnotationConfigWebApplicationContext refresh
WARNING: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'homeController': Unsatisfied dependency expressed through field 'userDAO'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.yogesh.shoponlineback.dao.UserDAO' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
Jan 10, 2017 3:19:23 PM org.springframework.web.servlet.DispatcherServlet initServletBean
SEVERE: Context initialization failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'homeController': Unsatisfied dependency expressed through field 'userDAO'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.yogesh.shoponlineback.dao.UserDAO' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:592)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:370)
    at `enter code here`org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1219)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:551)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:754)
    at** org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:540)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    at javax.servlet.GenericServlet.init(GenericServlet.java:158)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1183)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:992)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4903)

Answer 1

我已经更新到这个：

@ComponentScan(basePackages = "com.yogesh.shoponlinefrontend,com.yogesh.shoponlineback") 

从

@ComponentScan(basePackages = "com.yogesh.shoponlinefrontend) 

它现在工作正常。