Spring Boot @autowired does not work, classes in different package

By default, in Spring boot applications, component scan is done inside the package where your main class resides. any bean which is outside the package will not the created and thus gives the above mentioned exception.

Solution: you could either move the beans to the main spring boot class(which is not a good approach) or create a seperate configutation file and import it:



@Import({CustomConfigutation1.class, CustomConfiguration2.class})
@SpringBootpplication
public class BirthdayApplication {

public static void main(String [] args) {
springApplication.run(BirthdayApplication.class, args );
}
}

Add beans to these CustomConfiguration files.

package com.test.springboot;
@SpringBootApplication
@ComponentScan(basePackages = "com.test.springboot")
public class SpringBoot1Application {

public static void main(String[] args) {
ApplicationContext context= SpringApplication.run(SpringBoot1Application.class, args);

=====================================================================

package com.test.springboot;
@Controller
public class StudentController {
@Autowired
private StudentDao studentDao;

@RequestMapping("/")
public String homePage() {
return "home";
}

Another fun way you can screw this up is annotating a setter method's parameter. It appears that for setter methods (unlike constructors), you have to annotate the method as a whole.

This does not work for me:
`public void setRepository(@Autowired WidgetRepository repo)`

but this does:
`@Autowired public void setRepository(WidgetRepository repo)`

(Spring Boot 2.3.2)

When I add `@ComponentScan("com.firstday.spring.boot.services")` or `scanBasePackages{"com.firstday.spring.boot.services"}` jsp is not loaded. So when I add the parent package of project in @SpringBootApplication class it's working fine in my case

Code Example:-

package com.firstday.spring.boot.firstday;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication(scanBasePackages = {"com.firstday.spring.boot"})
public class FirstDayApplication {

public static void main(String[] args) {
SpringApplication.run(FirstDayApplication.class, args);
}

}