https://start.spring.io/

debug traffic http

application.properties:
spring.devtools.remote.secret=mysecret

shell:
  ssh:
    enabled: true
    port: 2222
  auth: spring

CommandLineRunner:
http://nixmash.com/java/using-spring-boot-commandlinerunner/
http://howtodoinjava.com/spring/spring-boot/command-line-runner-interface-example/
    -Drun.arguments="k1=v1,k2=v2,..."


class to remotely-debug:
org.springframework.boot.devtools.RemoteSpringApplication
Arguments:
    url (as in browser)


Annotations:

@SpringBootApplication
public class MyApplication ...

SpringApplicationBuilder

Every ApplicationContext has an Environment

@Value("${name}")
private String name
// java -jar yourapp.jar --name=BootDragon --server-port=9000
// or use application.[properties/yml]

// bean lifecycle
@PostConstruct
@PreDestroy

Testing
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = {
    SimpleClientApplication.class
})
public class SomeBlaBlaTests {
    ...
}

ErrorHandling:
https://www.toptal.com/java/spring-boot-rest-api-error-handling
https://auth0.com/blog/exception-handling-and-i18n-on-spring-boots-apis
https://habrahabr.ru/post/342214/
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/bind/annotation/ExceptionHandler.html
https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/bind/annotation/ControllerAdvice.html