Question

我正在尝试学习spring MVC并创建了一个休息服务，但我得到了bean自动装配问题。

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

我的春季项目的结构看起来像

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

以下是文件的外观

调度-servlet.xml中

<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>

弹簧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>

弹簧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>

所有其他实现，如控制器，DAO，服务和模型看起来像

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

将你的daoimpl标记为

@Repository public class userDaoImpl实现userDAO {}

自动装配界面而非标记具体类。使用java配置进行spring应用程序更容易理解。

Answer 2

您可以更改以下内容：

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

通过以下内容：

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

并查看结果？

Answer 3

你在豆子里有一个二传手注射你想自动装你必须做这样的事情

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

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

无法自动弹簧

3 个答案: