Could not autowire field/expected at least 1 bean which qualifies as autowire candidate - spring

Question

I am pretty new to Spring and although I have used it for a couple of projects before and I've seen a lot of similar questions, I can't figure out what is wrong with this exception:
SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'applicationController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public service.UserServiceI controller.ApplicationController.userService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [service.UserServiceI] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true), #org.springframework.beans.factory.annotation.Qualifier(value=userService)}
This is the relevant part of the stack trace.
Here is my controller class:
#Controller
#RequestMapping("/")
public class ApplicationController {
#Autowired
#Qualifier("userService")
public UserServiceI userService;
}
This is my UserService interface:
public interface UserService {
//methods
}
And the implementation:
#Service("userService")
public class UserServiceI implements UserService{
#Autowired
private UserDao dao;
//methods
}
Here is my XML configuration file:
<context:component-scan base-package="configuration">
</context:component-scan>
<bean id="resView" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/" />
<property name="suffix" value=".jsp" />
</bean>
<mvc:default-servlet-handler/>
<mvc:resources location="/resources/css/" mapping="/resources/css/*">
</mvc:resources>
<mvc:resources location="/resources/js/" mapping="/resources/js/*">
</mvc:resources>
<context:annotation-config></context:annotation-config>
<mvc:annotation-driven></mvc:annotation-driven>
<mvc:default-servlet-handler />
<context:component-scan base-package="controller">
</context:component-scan>
<context:component-scan base-package="dao"></context:component-scan>
<context:component-scan base-package="model"></context:component-scan>
<context:component-scan base-package="service"
use-default-filters="true">
</context:component-scan>
This is Spring configuration:
#Configuration
#EnableWebMvc
#ComponentScan(basePackages = "{configuration, controller, dao, model, service}")
public class SpringConfig extends WebMvcConfigurerAdapter{
#Override
public void configureViewResolvers(ViewResolverRegistry registry) {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setViewClass(JstlView.class);
viewResolver.setPrefix("/WebContent/");
viewResolver.setSuffix(".jsp");
registry.viewResolver(viewResolver);
}
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
}
}
And Hibernate configuration:
#Configuration
#EnableTransactionManagement
#ComponentScan({"configuration", "controller", "dao", "model", "service"})
#PropertySource(value = {"classpath:appProperties"})
public class HibernateConfig {
#Autowired
private Environment environment;
#Bean
public LocalSessionFactoryBean sessionFactory(){
LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
sessionFactory.setDataSource(dataSource());
sessionFactory.setPackagesToScan(new String[] {"model"});
sessionFactory.setHibernateProperties(hibernateProperties());
return sessionFactory;
}
#Bean
public DataSource dataSource(){
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(environment.getRequiredProperty("jdbc.driverClassName"));
dataSource.setUrl(environment.getRequiredProperty("jdbc.url"));
dataSource.setUsername(environment.getRequiredProperty("jdbc.username"));
dataSource.setPassword(environment.getRequiredProperty("jdbc.password"));
return dataSource;
}
#Bean
public Properties hibernateProperties(){
Properties hibernateProperties = new Properties();
hibernateProperties.put("hibernate.dialect",environment.getRequiredProperty("hibernate.dialect"));
hibernateProperties.put("hibernate.show_sql", environment.getRequiredProperty("hibernate.show_sql"));
hibernateProperties.put("hibernate.format_sql", environment.getRequiredProperty("hibernate.format_sql"));
return hibernateProperties;
}
#Bean
#Autowired
public HibernateTransactionManager transactionManager(SessionFactory s) {
HibernateTransactionManager txManager = new HibernateTransactionManager();
txManager.setSessionFactory(s);
return txManager;
}
}
And pom.xml
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.2.3</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.6.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.31</version>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2</version>
</dependency>
I commented the code in Controller and the result was that it was unable to autowire SessionFactory, although it is defined. Please help me!

Answer 1

Few things:
You should autowire the interface, and not the implementation:
#Autowired
public UserService userService;
Remove the value param being passed to the #Service in UserServiceI, unless you want to use some fancy name, otherwise Spring will use the name of the bean in lowercases automatically (remember you should be autowiring the interface);
Are you sure your packages are named only controller, dao, etc and not xxx.yyy.controller? Because if they have a prefix, your scan is incorrect here:
<context:component-scan base-package="service"
use-default-filters="true">
</context:component-scan>
3.1. Just a tip, but you can use comma to separate your packages, instead of multiple declarations:
<context:component-scan base-package="service, dao, controller, ..." />

Answer 2

To debug, temporarily comment :
#Autowired
#Qualifier("userService")
public UserServiceI userService;
and print all the beans loaded by spring container in your controller :
#Autowired
private ApplicationContext applicationContext;
#RequestMapping("/print")
public void print() {
String[] beanNames = applicationContext.getBeanDefinitionNames();
for (String beanName : beanNames) {
System.out.println(beanName + " : " + applicationContext.getBean(beanName).getClass().toString());
}
}
and make sure your service bean is loaded.