无法自动弹簧

Question

I am trying to learn spring MVC and created a rest service but I am getting bean autowiring problem.

Could not autowire field: taxApp.dao.daoImpl.userDaoImpl taxApp.controller.loginController.userService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [taxApp.dao.daoImpl.userDaoImpl] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency

The structure of my spring project looks like

src
   main
       java
           taxApp
                 controller
                           loginController.java
                 model
                      user.java
                 dao
                    daoImpl
                           userDaoImpl.java
                    userDAO.java
       resources
                database
                        data-source-cfg.xml
                user 
                    spring-user.xml
                spring-module.xml
       webapp
             web-inf
                    dispatcher-servlet.xml
                    web.xml
             index.jsp

Following is how the files looks like

dispatcher-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context.xsd">

  <mvc:annotation-driven/>
  <context:component-scan base-package="taxApp" />
  <context:annotation-config />

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

</beans>

spring-user.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="userDAO" class="dao.impl.userDaoImpl">
        <property name="dataSource" ref="dataSource" />
    </bean>

</beans>

spring-module.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
  http://www.springframework.org/schema/beans/spring-beans.xsd">

  <!-- Using Oracle datasource -->
  <import resource="database/data-source-cfg.xml" />
  <import resource="dao/spring-user.xml" />

</beans>

All the other implementation like controller, DAO, service and model look like

loginController.java

@RestController
public class loginController {
    @Autowired
    userDaoImpl userService;  //Service which will do all data retrieval/manipulation work
    //other methods
}

userDAO.java

public interface userDAO {
    public void insert(user _user);
    public user findUserByEmail(String email);
}

userDaoImpl.java

public class userDaoImpl implements userDAO{

    private DataSource dataSource;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }
    //other methods
}

Answer 1

Mark your daoimpl as

@repository public class userDaoImpl implements userDAO{}

Autowire interface rather marking an concrete class. Go with java config for spring application much easier to understand.

Answer 2

Could you change the following:

@RestController
public class loginController {
    @Autowired
    userDaoImpl userService;  //Service which will do all data retrieval/manipulation work
    //other methods
}

by the following:

@RestController
public class loginController {
    @Autowired
    @Qualifier("userDAO")
    userDaoImpl userService;  //Service which will do all data retrieval/manipulation work
    //other methods
}

and see the result?

Answer 3

ur having one setter injection in the bean u want to autowire u have to do something like this

//Autowired annotation on variable/setters is equivalent to autowire="byType"
    @Autowired
    private Employee employee;

    @Autowired
    public void setEmployee(Employee emp){
        this.employee=emp;
    }