@Autowired doesn't work correctly as expected in Spring components

Question

I have a very simple configuration and a big confusion that I need help resolving.

I have a BaseController which is annotated with @RestController. In this class I have a method that returns a String and is annotated with @GetMapping. I am reading properties file from it and displaying the application value. Till here, all works GOOD. Below are my files,

@RestController
public class BaseController {

    @Autowired
    Environment env;

    @GetMapping("/hello")
    public String hello() {
        String myAppName = env.getProperty("spring.application.name");
        return "From Controller -> " + myAppName;
    }
}

My application.properties file,

server.servlet.context-path=/BootEnv
server.port=8085
spring.application.name=EnvironmentAPITester

When I hit,

http://localhost:8085/BootEnv/hello

, I get proper response like below,

From Controller -> EnvironmentAPITester

Here in code, Environment variable is org.springframework.core.env.Environment;

All is GOOD till here.

Now I have created a new @Configuration class named ApplicationConfig. I want to read the properties file from that class as well and return the values. So below are the changes I did,

@RestController
public class BaseController {

    @Autowired
    Environment env;

    @GetMapping("/hello")
    public String hello() {
        String myAppName = env.getProperty("spring.application.name");
        return "From Controller -> " + myAppName;
    }

    @GetMapping("/helloConf")
    public String getDetails() {
        ApplicationConfig conf = new ApplicationConfig();
        String fromConfig = conf.details();
        return "From Config -> "+fromConfig;
    }
}

And the class below,

@Configuration
public class ApplicationConfig{

    @Autowired
    Environment env;

    public String details() {
        return env.getProperty("spring.application.name");
    }
}

Now when I hit,

http://localhost:8085/BootEnv/helloConf

I get a null pointer exception as the Environment variable is null and does NOT get auto configured. HOW? And WHY?

After googling, I came to a solution which asked me to implement EnvironmentAware interface and set the Environment variable that way. So below are the changes I had to make to my ApplicationConfig class,

@Configuration
public class ApplicationConfig implements EnvironmentAware{

    @Autowired
    Environment env;

    public String details() {
        return env.getProperty("spring.application.name");
    }

    @Override
    public void setEnvironment(Environment environment) {
        this.env = environment;     
    }
}

After doing this also, it still gave me null pointer exception for the same Environment variable value. Then I figured out that not only I had to remove the @Autowire annotation but I ALSO needed to make that variable static to make it work. So when I do,

//@Autowired
static Environment env;

It works perfectly. And when I hit,

http://localhost:8085/BootEnv/helloConf

I get proper response,

From Config -> EnvironmentAPITester

The confusion is WHY do I need to make it static so that it fills the value? Why the EnvironmentAware implementation can't set the Environment variable while it is still @Autowired?

And why in the first place, @Autowired does not fill the Environment variable when the class ApplicationConfig class is marked with @Configuration annotation? Even if I change this class annotation to @Service or @Repository or @Component the same issue persists of failing to@Autowire the Environment variable. How come?

I know it's a long post. But any clarification on this is highly appreciated as I am having hard time understanding this.

Thanks for your help in advance.