Question

我有clientDAO接口和clientDaoImpl类;我在clientDAO中声明了方法并在clientDaoImpl中定义了方法。我还在spring-servlet.xml（它是spring-config文件）中定义了mysql数据库连接作为数据源。

import java.util.Date;
import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.bind.annotation.RequestMapping;

@SessionAttributes
@Controller 
public class clientRegistrationController {
@Autowired
private clientDAO clientdao;
     @SessionAttributes
    @Controller 
    public class ClientRegistrationController {


    @RequestMapping( value="/registration",method = RequestMethod.POST)
        public @ResponseBody  
       String client_registration(@RequestParam(value = "date_of_registration") Date date_of_registration)

      // here i want to get pojo object and call method insert method which is 
      // defined in DAO implement class.
                return " Registered successfully";    

        }
@RequestMapping("/registration")
    public ModelAndView showContacts() {
    String message = "Hello World, Spring MVC @ Javatpoint";
        return new ModelAndView("client_registration", "message",message);
    }
}

我收到了以下错误：

SEVERE: Servlet [spring] in web application [/SpringTiles] threw load() exception
java.lang.Error: Unresolved compilation problems: 
    Autowired cannot be resolved to a type
    clientDAO cannot be resolved to a type

我在javatpoint.com中使用了/ SpringTiles代码这是我的客户端：

package dao;

import com.javatpoint.form.Client_Registration;

public interface clientDAO {
void insertData(Client_Registration patient);
}

Answer 1

如果没有创建任何类型的bean，则会出现此异常。确保在spring-servlet.xml文件中添加了context：component-scan标记。例如

并检查是否在Dao上添加了@Repository注释

Answer 2

希望您在clientDAO类中添加了@Repository。 Spring无法在加载时找到它。检查您用于创建bean的配置（xml或java）。共享完整的错误日志以及相关的代码片段（此处为clientDAO和配置）有助于更快地解决错误。

Answer 3

你应该这样注射DAO：

<bean id="dao" class="com.elgarnaoui.ma.dao.AgentDao"></bean>
    <bean id="metier" class="com.elgarnaoui.ma.metier.MetierAgent">
        <property name="dao" ref="dao"></property>
    </bean>

如何通过弹簧控制器使用DAO方法将数据插入数据库？

3 个答案: