org.springframework.beans.factory.NoSuchBeanDefinitionException：未定义名为“ leadDAO”的bean

Question

我想运行spring + JDBC + Webservice程序。 运行this.org.springframework.beans.factory.NoSuchBeanDefinitionException时获取异常：未定义名为'leadDAO'的bean

请帮忙。 我被困住了。 谢谢

Web.xml

<!-- Processes application requests -->
    <servlet>
    <servlet-name>spring</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>spring</servlet-name>
        <url-pattern>/lms/*</url-pattern>
    </servlet-mapping>

    <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/spring-servlet.xml, /WEB-INF/applicationContext.xml</param-value>
</context-param>


 <!-- Creates the Spring Container shared by all Servlets and Filters -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

</web-app>

现在我的spring-servlet.xml

      <bean id="viewResolver" 
       class="org.springframework.web.servlet.view.InternalResourceViewResolver">
         <property name="prefix" value="/WEB-INF/jsp/"/>
            <property name="suffix" value=".jsp"/>
      </bean>


    <!-- declare datasource bean -->  
      <bean id="dataSource"  class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
          <property name="driverClassName" value="com.mysql.jdbc.Driver" />  
          <property name="url" value="jdbc:mysql://localhost:3307/lms" />  
          <property name="username" value="root" />  
          <property name="password" value="" />  
     </bean>


     <!-- declare beans -->  
      <bean id="leadDAO" class="com.varazo.dao.LeadDAOImpl">
        <!-- <property name="dataSource" ref="dataSource"></property>   -->
     </bean>

      <bean id="newLeadService" class="com.varazo.service.NewLeadService"/>

</beans>

applicationContext.xml

 <import resource="classpath*:spring-servlet.xml"/>
 <!-- Activates various annotations to be detected in bean classes -->
 <context:annotation-config />


        <!-- Scans the classpath for annotated components that will be auto-registered as Spring beans.
  For example @Controller and @Service. Make sure to set the correct base-package-->
 <context:component-scan base-package="com.varazo.dao" />
 <context:component-scan base-package="com.varazo.service" />
 <context:component-scan base-package="com.varazo.app" />
 <context:component-scan base-package="com.varazo.pojo" />

 <!-- Configures the annotation-driven Spring MVC Controller programming model.
 Note that, with Spring 3.0, this tag works in Servlet MVC only!  -->
 <mvc:annotation-driven />

</beans>

和bean类：

package com.varazo.pojo;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="newlead")
public class NewLead {
     private Long id;
     private String firstName;
     private String lastName;
     private Double money;

     public Long getId() {
      return id;
     }
     public void setId(Long id) {
      this.id = id;
     }
     public String getFirstName() {
      return firstName;
     }
     public void setFirstName(String firstName) {
      this.firstName = firstName;
     }
     public String getLastName() {
      return lastName;
     }
     public void setLastName(String lastName) {
      this.lastName = lastName;
     }
     public Double getMoney() {
      return money;
     }
     public void setMoney(Double money) {
      this.money = money;
     }
}

我的服务班

  package com.varazo.service;

import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Service;

import com.varazo.dao.LeadDAOImpl;
import com.varazo.pojo.NewLead;


@Service("newLeadService")
public class NewLeadService {

/**
 * Retrieves all persons
 */
public List<NewLead> getAll() {

    // logger.debug("Retrieving all persons");
     System.out.println("Retrieving all persons 1");
    ApplicationContext context = new ClassPathXmlApplicationContext("classpath*:spring-servlet.xml");
    System.out.println("Retrieving all persons 2");
            LeadDAOImpl leadDAOImplObj = (LeadDAOImpl) context.getBean("leadDAO");
            List<NewLead> lList = new ArrayList<NewLead>();
            lList = leadDAOImplObj.listNewLeads();
      System.out.println("Retrieving all persons "+lList);

 return lList;
}

}

我的daoImpl

   package com.varazo.dao;

import java.util.List;

import javax.sql.DataSource;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import com.varazo.pojo.NewLead;
@Repository
public class LeadDAOImpl implements LeadDAO {
       private DataSource dataSource;
       private JdbcTemplate jdbcTemplate;  

       public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {  
           this.jdbcTemplate = jdbcTemplate;  
       }  


     public List<NewLead> listNewLeads() {

            JdbcTemplate select = new JdbcTemplate(dataSource);
            return select.query("select ID from llead LIMIT 2", new LeadRowMapper());
       }


    }

我的控制器

package com.varazo.app;

import javax.annotation.Resource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import com.varazo.pojo.NewLead;
import com.varazo.pojo.NewLeadList;

@Controller
@RequestMapping("/lead")
public class LeadController {


     @Resource(name="newLeadService")
     private com.varazo.service.NewLeadService newLeadService;

     @RequestMapping(value = "/newLeads", method = RequestMethod.GET, headers="Accept=application/xml, application/json")
         public @ResponseBody com.varazo.pojo.NewLeadList getNewLead() {

          // Call service here
         NewLeadList result = new NewLeadList();
          result.setData(newLeadService.getAll());
          System.out.println("*********************LeadController Retrieving all persons ***"+result+"****************"); 
          return result;
         }

}

网址：

/ lms-mobile / lms / lead / newLeads

Answer 1

一：

为什么要两次声明bean？

 <bean id="leadDAO" class="com.varazo.dao.LeadDAOImpl">
    <!-- <property name="dataSource" ref="dataSource"></property>   -->
 </bean>

和

@Repository
public class LeadDAOImpl implements LeadDAO {

二：

如何注入以下两个依赖项：

@Repository
public class LeadDAOImpl implements LeadDAO {
       private DataSource dataSource;
       private JdbcTemplate jdbcTemplate; 

三：

你可以从

<context:component-scan base-package="com.varazo.dao" />
<context:component-scan base-package="com.varazo.service" />
<context:component-scan base-package="com.varazo.app" />
<context:component-scan base-package="com.varazo.pojo" />

要（不是很确定，但是您只能有一个声明）

<context:component-scan base-package="com.varazo.dao,com.varazo.service,com.varazo.app, com.varazo.pojo" />

四：

为什么从@Service类中选择以下内容？

ApplicationContext context = new ClassPathXmlApplicationContext("classpath*:spring-servlet.xml");

这样做确实是一个坏习惯，@ Service一定不具备有关Web层的知识。

我建议改为

@Service("newLeadService")
public class NewLeadService {

private LeadDAO leadDAOImplObj;

@Autowired
public NewLeadService(LeadDAO leadDAOImplObj){
     this.leadDAOImplObj = leadDAOImplObj;
}

public List<NewLead> getAll() {

    // logger.debug("Retrieving all persons");
     System.out.println("Retrieving all persons 1");
    System.out.println("Retrieving all persons 2");
    List<NewLead> lList = new ArrayList<NewLead>();
    lList = leadDAOImplObj.listNewLeads();
    System.out.println("Retrieving all persons "+lList);

    return lList;
}

五：

阅读有关DI的所有参考文档，您所做的事情确实是错误的。 您必须在基于接口的Java类中声明依赖项，而不是通过具体类声明。 您的@Service类未实现接口。