Spring Configuration with annotations #Autowired not working - step by step - spring

Question

I have performed this steps in order to use annotation based configuration:
a) beans.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"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd">
<context:annotation-config/>
<context:component-scan base-package="test.*"/>
</beans>
b) then I have this component:
package test;
#Component
public class InMemoryUserService implements UserService
c) then I try to use autowire:
#Autowired
private UserService userService;
and in runtime userService is null.
Basic stuff is set up properly (like dependencies etc.) because in first version of the test app I was using xml based configuration and it was working smoothly.
And this is a class that uses autowireing:
public class DemoApplication {
#Autowired
private UserService userService;
public DemoApplication() {
}
public static void main(String[] args) {
DemoApplication da = new DemoApplication();
da.userService.getUserByEmail("blabla#gmail.com");
}
}
Is there anything else I'm missing?

Answer 1

That is because -
DemoApplication is not a spring managed bean. Make it spring managed by adding #Component similar to UserService.
Use spring bean factory or application context, say ClasspathXMLApplicationContext, to get the DemoApplication instead of new operator.

Answer 2

How will spring know that it has to run this DemoApplication.
You have to run it with a SpringJunit4ClassRunner something like below:
Annotate your DemoApplication as shown below:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration
public class DemoApplication {
#Autowired
private UserService userService;
#Test
public void testBean() {
userService.getUserByEmail("");
}
}