How can I run a specific class / utility in a Spring Boot application with wiring? - spring

Question

I have my standard Spring Boot application working. I have situations where I want to run a "job" which is basically some specific method normally run via a user doing something in their browser but I want to run it from command line.
I'm able to run an arbitrary class with gradlew;
./gradlew -PmainClass=kcentral.backingservices.URLMetaExtractor execute
However when run this way none of the "autowiring" works. What is a better way to execute an arbitrary class (that has a main method) such that it also works with any Autowiring?
EDIT:
I got some advice to use a CommandLineRunner and some args, which work to execute the command via:
./gradlew bootRun -Pargs=--reloadTestData
However, the Autowiring of my Repo is failing. What I have is:
#EnableAutoConfiguration
#EnableMongoAuditing
#EnableMongoRepositories(basePackageClasses=KCItemRepo.class)
#ComponentScan(basePackages = {"kcentral"})
public class ReloadTestData implements CommandLineRunner {
#Autowired
AddItemService addItemService;
#Autowired
KCItemRepo itemRepo;
#Autowired
KCItemRatingRepo itemRatingRepo;
private static final Logger log = LoggerFactory.getLogger(ReloadTestData.class);
public void reloadData(){
log.info("reloadData and called");
if (itemRepo == null){
log.error("Repo not found");
return;
}
long c = itemRepo.count();
log.warn("REMOVING ALL items "+c);
itemRepo.deleteAll();
log.warn("REMOVING ALL ratings");
itemRatingRepo.deleteAll();
}
itemRepo is always null even though I wire the same way in my 'regular' spring boot app without an issue. What do I need to do to have it wire properly?

Answer 1

The fact that you say you want to run a "job" suggests that you might want to use a scheduled task within your application, rather than trying to run it through the command line. e.g. Scheduling tasks in Spring
#Scheduled(fixedRate = 5000)
public void reportCurrentTime() {
log.info("The time is now {}", dateFormat.format(new Date()));
}
If you want to make a command line application work with Autowiring, you can make a command line application by making your Application class implement the CommandLineRunner interface, e.g. Spring Boot Console App
#SpringBootApplication
public class SpringBootConsoleApplication
implements CommandLineRunner {
public static void main(String[] args) {
SpringApplication.run(SpringBootConsoleApplication.class, args);
}
#Override
public void run(String... args) {
}
}
And add spring.main.web-application-type=NONE to the properties file.

Answer 2

If you want to stop the application after running you can use SpringApplication.exit(ctx). Don't know about your auto-wiring problem though, maybe try printing out the list of available beans which might give some insight. Example:
#Component
public class DoThenQuit implements CommandLineRunner {
#Autowired
private ApplicationContext ctx;
#Override
public void run(String[] args) {
// do some other stuff before quitting
String[] beanNames = ctx.getBeanDefinitionNames();
Arrays.stream(beanNames).forEach(System.out::println);
// then quit the application
SpringApplication.exit(ctx);
}
}