Why isn't #Autowired working in my Spring MVC #Controller? - spring

Question

I have a Spring MVC project going.
I have a WebController that has an #Autowired service.
When I run the web app on the server, the WebController is created but it doesn't autowire the service.
Been really banging my head against a wall trying to figure this out ... Any idea what's wrong?
Here's the error I get ...
org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'webController':
Unsatisfied dependency expressed through field 'myAppService';
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException:
No qualifying bean of type 'com.mycompany.myapp.controller.MyAppService'
available: expected at least 1 bean which qualifies as
autowire candidate. Dependency annotations:
{#org.springframework.beans.factory.annotation.Autowired(required=true)}
Here's my web.xml ...
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<display-name>Archetype Created Web Application</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
Here's my dispatcher-servlet.xml ...
<?xml version="1.0" encoding="UTF-8"?>
<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">
<context:component-scan base-package="com.mycompany.myapp" />
<mvc:annotation-driven />
<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>
I have a WebController like so ...
package com.mycompany.myapp.controller;
import java.util.Set;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import com.mycompany.myapp.model.TableRecord;
#Controller
public class WebController {
#Autowired
MyAppService myAppService;
#RequestMapping(value = "/showprojects", method = RequestMethod.GET)
public ModelAndView showProjects(Model model) {
ModelAndView mav = new ModelAndView();
try {
Set<TableRecord> recProjects = myAppService.getProjects();
model.addAttribute("projects", recProjects);
} catch (Exception x) {
x.printStackTrace();
}
mav.setViewName("projects");
return mav;
}
Here's my Service interface ...
package com.mycompany.myapp.controller;
import java.util.Set;
import org.springframework.stereotype.Component;
import com.mycompany.myapp.model.TableRecord;
#Component
public interface MyAppService {
public Set<TableRecord> getProjects() throws Exception;
}
And here's my Service implementation ...
package com.mycompany.myapp.controller;
import java.util.Set;
import org.springframework.stereotype.Component;
/* ... other import statements ... */
#Component
public class MyAppServiceImpl {
public MyAppServiceImpl() throws Exception {
/* ... some initialization of member variables
and db connection ... */
}
public Set<TableRecord> getProjects() throws Exception {
/* ... implementation that returns a Set... */
}
}

Answer 1

You didnt implement the interface in your service class- Change it as below-
public class MyAppServiceImpl implements MyAppService {
}
It should better to use #Service annoation for service class instead of #Component

Answer 2

Your MyAppServiceImpl class does not implement the MyAppService interface.