튜토리얼: Spring Boot와 통합

git clone git@github.com:mongodb-developer/mdb-spring-boot-reactive.git

spring.data.mongodb.uri=<connection URI>

mongosh "<connection URI>" --file setup.js

@RestController
public class AccountController {
   //...
   @PostMapping("/account")
   public Mono<Account> createAccount(@RequestBody Account account) {
       return accountRepository.save(account);
   }
   @GetMapping("/account/{accountNum}")
   public Mono<Account> getAccount(@PathVariable String accountNum) {
       return accountRepository.findByAccountNum(accountNum)
           .switchIfEmpty(Mono.error(new AccountNotFoundException()));
   }
   //...
}

@RestController
public class AccountController {
   //...
   @PostMapping("/account/{accountNum}/debit")
   public Mono<Txn> debitAccount(@PathVariable String accountNum,
                                 @RequestBody Map<String, Object> requestBody) {
       //...
       txn.addEntry(new TxnEntry(accountNum, amount));
       return txnService.saveTransaction(txn).flatMap(txnService::executeTxn);
   }
   @PostMapping("/account/{accountNum}/credit")
   public Mono<Txn> creditAccount(@PathVariable String accountNum,
                                  @RequestBody Map<String, Object> requestBody) {
       //...
       txn.addEntry(new TxnEntry(accountNum, -amount));
       return txnService.saveTransaction(txn).flatMap(txnService::executeTxn);
   }
   @PostMapping("/account/{from}/transfer")
   public Mono<Txn> transfer(@PathVariable String from,
                             @RequestBody TransferRequest transferRequest) {
       //...
       txn.addEntry(new TxnEntry(from, -amount));
       txn.addEntry(new TxnEntry(to, amount));
       return txnService.saveTransaction(txn).flatMap(txnService::executeTxn);
   }
   //...
}

public interface AccountRepository extends ReactiveMongoRepository<Account, String> {
   @Query("{accountNum:'?0'}")
   Mono<Account> findByAccountNum(String accountNum);
   @Update("{'$inc':{'balance': ?1}}")
   Mono<Long> findAndIncrementBalanceByAccountNum(String accountNum, double increment);
}

@Service
public class TxnService {
   //...
   public Mono<Txn> saveTransaction(Txn txn) {
       return txnTemplate.save(txn);
   }
   public Mono<Txn> executeTxn(Txn txn) {
       return updateBalances(txn)
           .onErrorResume(DataIntegrityViolationException.class
               /*lambda expression to handle error*/)
           .onErrorResume(AccountNotFoundException.class
               /*lambda expression to handle error*/)
           .then(txnTemplate.findAndUpdateStatusById(txn.getId(), TxnStatus.SUCCESS));
   }
   public Flux<Long> updateBalances(Txn txn) {
       Flux<Long> updatedCounts = Flux.fromIterable(txn.getEntries()).concatMap(
           entry -> accountRepository.findAndIncrementBalanceByAccountNum(
               entry.getAccountNum(), entry.getAmount())
       );
       return updatedCounts.handle(/*...*/);
   }
}

@Service
public class TxnTemplate {
   //...
   public Mono<Txn> save(Txn txn) {
       return template.save(txn);
   }
   public Mono<Txn> findAndUpdateStatusById(String id, TxnStatus status) {
      Query query = query(where("_id").is(id));
      Update update = update("status", status);
      FindAndModifyOptions options = FindAndModifyOptions.options().returnNew(true);
      return template.findAndModify(query, update, options, Txn.class);
   }
   //...
}

@Configuration
public class ReactiveMongoConfig extends AbstractReactiveMongoConfiguration {
   //...
   @Bean
   ReactiveMongoTransactionManager transactionManager(ReactiveMongoDatabaseFactory dbFactory) {
       return new ReactiveMongoTransactionManager(dbFactory);
   }
}

mvn spring-boot:run

curl --location 'localhost:8080/account' \
--header 'Content-Type: application/json' \
--data '{
   "accountNum": "12345"
}'

curl --location 'localhost:8080/account/12345/debit' \
--header 'Content-Type: application/json' \
--data '{
   "amount": 1000
}'

curl --location 'localhost:8080/account' \
--header 'Content-Type: application/json' \
--data '{
   "accountNum": "67890"
}'

curl --location 'localhost:8080/account/12345/transfer' \
--header 'Content-Type: application/json' \
--data '{
   "to": "67890",
   "amount": 500
}'