exceeding maximum value for single transaction and daily transactions.

Author: mertakdut

BankApplicationBackend/src/main/java/com/demo/bankapp/configuration/DatabaseMocker.java

@@ -27,8 +27,14 @@ CommandLineRunner initDatabase(UserRepository repository, UserController userCon
 			cnuRequest2.setPassword("mert1234");
 			cnuRequest2.setTcno("23141232212");
 
+			CreateNewUserRequest cnuRequest3 = new CreateNewUserRequest();
+			cnuRequest3.setUsername("Mert3");
+			cnuRequest3.setPassword("mert12345");
+			cnuRequest3.setTcno("23141232213");
+
 			userController.createNewUser(cnuRequest);
 			userController.createNewUser(cnuRequest2);
+			userController.createNewUser(cnuRequest3);
 			// repository.save(new User("Bilbo Baggins", "burglar", "128185822"));
 			// repository.save(new User("Frodo Baggins", "thief", "21528582"));
 		};

BankApplicationBackend/src/main/java/com/demo/bankapp/controller/TransferController.java

@@ -1,5 +1,10 @@
 package com.demo.bankapp.controller;
 
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.List;
+import java.util.Map;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.hateoas.Resource;
 import org.springframework.http.MediaType;
@@ -11,6 +16,7 @@
 
 import com.demo.bankapp.assembler.TransferResourceAssembler;
 import com.demo.bankapp.exception.BadRequestException;
+import com.demo.bankapp.exception.TransactionLimitException;
 import com.demo.bankapp.model.Transfer;
 import com.demo.bankapp.model.User;
 import com.demo.bankapp.request.MakeTransferRequest;
@@ -50,11 +56,23 @@ public Resource<Transfer> makeTransfer(@RequestBody MakeTransferRequest request)
 			throw new BadRequestException("Invalid TCNo.");
 		}
 
-		if (request.getAmount().signum() == 0 || request.getAmount().signum() == -1) {
+		if (request.getAmount() == null || request.getAmount().signum() == 0 || request.getAmount().signum() == -1) {
 			throw new BadRequestException("Please enter a valid amount.");
 		}
 
+		Map<String, Double> currencyRates = wealthService.getCurrencyRates();
+
+		BigDecimal singleTransferLimit = new BigDecimal(20000);
+		BigDecimal tryEquivalent = getTryEquivalent(currencyRates, request.getCurrency(), request.getAmount());
+		if (tryEquivalent.compareTo(singleTransferLimit) == 1) {
+			throw new TransactionLimitException("Exceeded Maximum Value Per Transaction.");
+		}
+
 		User senderUser = userService.findByUserName(request.getSenderUsername());
+
+		List<Transfer> last24HourTransfers = transferService.findAllTransfersFrom24Hours(senderUser.getId());
+		checkDailyTransferLimitExceedition(currencyRates, last24HourTransfers, tryEquivalent);
+
 		User receiverUser = userService.findByTcno(request.getReceiverTcno());
 
 		if (senderUser.equals(receiverUser)) {
@@ -68,4 +86,27 @@ public Resource<Transfer> makeTransfer(@RequestBody MakeTransferRequest request)
 		return assembler.toResource(transfer);
 	}
 
+	private BigDecimal getTryEquivalent(Map<String, Double> currencyRates, String currency, BigDecimal amount) {
+		BigDecimal transferCurrRate = new BigDecimal(currencyRates.get(currency));
+		return amount.divide(transferCurrRate, 9, RoundingMode.HALF_UP);
+	}
+
+	private void checkDailyTransferLimitExceedition(Map<String, Double> currencyRates, List<Transfer> last24HourTransfers, BigDecimal transferTryEquivalent) {
+
+		BigDecimal dailyTransferLimit = new BigDecimal(100000);
+
+		BigDecimal rate;
+		BigDecimal tryEquivalent;
+		for (Transfer transfer : last24HourTransfers) {
+			rate = new BigDecimal(currencyRates.get(transfer.getCurrency()));
+			tryEquivalent = transfer.getAmount().divide(rate, 9, RoundingMode.HALF_UP);
+
+			transferTryEquivalent = transferTryEquivalent.add(tryEquivalent);
+			if (transferTryEquivalent.compareTo(dailyTransferLimit) != -1) {
+				throw new TransactionLimitException("Exceeded Maximum Transaction Value For the Day.");
+			}
+		}
+
+	}
+
 }

BankApplicationBackend/src/main/java/com/demo/bankapp/exception/TransactionLimitException.java

@@ -0,0 +1,9 @@
+package com.demo.bankapp.exception;
+
+public class TransactionLimitException extends RuntimeException {
+
+	public TransactionLimitException(String message) {
+		super("Transaction Limit: " + message);
+	}
+
+}

BankApplicationBackend/src/main/java/com/demo/bankapp/exception/configuration/RestExceptionHandler.java

@@ -28,6 +28,7 @@
 import com.demo.bankapp.exception.BadCredentialsException;
 import com.demo.bankapp.exception.BadRequestException;
 import com.demo.bankapp.exception.InsufficientFundsException;
+import com.demo.bankapp.exception.TransactionLimitException;
 import com.demo.bankapp.exception.UserNotFoundException;
 
 @ControllerAdvice
@@ -175,6 +176,12 @@ public ResponseEntity<Object> handle(final InsufficientFundsException ex, final
 		final ApiError apiError = new ApiError(HttpStatus.UNAUTHORIZED, ex.getLocalizedMessage(), "error occurred");
 		return buildResponseEntity(ex, apiError);
 	}
+	
+	@ExceptionHandler({ TransactionLimitException.class })
+	public ResponseEntity<Object> handle(final TransactionLimitException ex, final WebRequest request) {
+		final ApiError apiError = new ApiError(HttpStatus.UNAUTHORIZED, ex.getLocalizedMessage(), "error occurred");
+		return buildResponseEntity(ex, apiError);
+	}
 
 	private ResponseEntity<Object> buildResponseEntity(Exception ex, ApiError apiError) {
 		logger.info(ex.getClass().getName());

BankApplicationBackend/src/main/java/com/demo/bankapp/repository/TransferRepository.java

@@ -1,11 +1,18 @@
 package com.demo.bankapp.repository;
 
+import java.util.List;
+
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.data.rest.core.annotation.RepositoryRestResource;
 
 import com.demo.bankapp.model.Transfer;
 
 @RepositoryRestResource(exported = false)
 public interface TransferRepository extends JpaRepository<Transfer, Long> {
 
+	@Query(value = "SELECT t FROM Transfer t WHERE t.fromUserId = :userId and t.transferTime >= DATEADD(day, -1, GETDATE())")
+	List<Transfer> findAllTransfersFrom24Hours(@Param("userId") Long userId);
+
 }

BankApplicationBackend/src/main/java/com/demo/bankapp/service/abstractions/ITransferService.java

@@ -1,9 +1,13 @@
 package com.demo.bankapp.service.abstractions;
 
+import java.util.List;
+
 import com.demo.bankapp.model.Transfer;
 
 public interface ITransferService {
 
 	Transfer createNewTransfer(Transfer transfer);
+	
+	List<Transfer> findAllTransfersFrom24Hours(Long userId);
 
 }

BankApplicationBackend/src/main/java/com/demo/bankapp/service/abstractions/IWealthService.java

@@ -1,6 +1,7 @@
 package com.demo.bankapp.service.abstractions;
 
 import java.math.BigDecimal;
+import java.util.Map;
 
 import com.demo.bankapp.model.Wealth;
 
@@ -9,6 +10,8 @@ public interface IWealthService {
 	void newWealthRecord(Long userId);
 
 	Wealth findWealth(Long userId);
+	
+	Map<String, Double> getCurrencyRates();
 
 	void makeWealthExchange(Long userId, String currency, BigDecimal amount, boolean isBuying);
 

BankApplicationBackend/src/main/java/com/demo/bankapp/service/concretions/TransferService.java

@@ -1,5 +1,7 @@
 package com.demo.bankapp.service.concretions;
 
+import java.util.List;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
@@ -17,5 +19,10 @@ public class TransferService implements ITransferService {
 	public Transfer createNewTransfer(Transfer transfer) {
 		return repository.save(transfer);
 	}
+	
+	@Override
+	public List<Transfer> findAllTransfersFrom24Hours(Long userId) {
+		return repository.findAllTransfersFrom24Hours(userId);
+	}
 
 }

BankApplicationBackend/src/main/java/com/demo/bankapp/service/concretions/WealthService.java

@@ -32,7 +32,7 @@ public void makeWealthExchange(Long userId, String currency, BigDecimal amount,
 			throw new BadRequestException("Invalid currency.");
 		}
 
-		BigDecimal rate = new BigDecimal(getCurrencyRate(currency));
+		BigDecimal rate = new BigDecimal(getCurrencyRates().get(currency));
 		BigDecimal tryEquivalent = amount.divide(rate, 9, RoundingMode.HALF_UP);
 
 		if (isBuying) {
@@ -86,7 +86,7 @@ public void newWealthRecord(Long userId) {
 
 		Map<String, BigDecimal> wealthMap = new HashMap<>();
 
-		Map<String, Double> currencyMap = getCurrencyMap();
+		Map<String, Double> currencyMap = getCurrencyRates();
 		for (Map.Entry<String, Double> entry : currencyMap.entrySet()) {
 			wealthMap.put(entry.getKey(), BigDecimal.ZERO);
 		}
@@ -102,6 +102,14 @@ public Wealth findWealth(Long userId) {
 		return repository.findById(userId).orElseThrow(() -> new UserNotFoundException());
 	}
 
+	@Override
+	public Map<String, Double> getCurrencyRates() {
+		final String uri = "https://api.exchangeratesapi.io/latest?base=TRY";
+
+		RestTemplate restTemplate = new RestTemplate();
+		return ((Map<String, Map<String, Double>>) restTemplate.getForObject(uri, Map.class)).get("rates");
+	}
+
 	private void addInitialBalance(Map<String, BigDecimal> wealthMap) {
 		String currency = "TRY";
 
@@ -112,16 +120,4 @@ private void addInitialBalance(Map<String, BigDecimal> wealthMap) {
 		wealthMap.put(currency, finalAmount);
 	}
 
-	private Map<String, Double> getCurrencyMap() {
-		final String uri = "https://api.exchangeratesapi.io/latest?base=TRY";
-
-		RestTemplate restTemplate = new RestTemplate();
-		return ((Map<String, Map<String, Double>>) restTemplate.getForObject(uri, Map.class)).get("rates");
-	}
-
-	private double getCurrencyRate(String currency) {
-		Map<String, Double> currencyMap = getCurrencyMap();
-		return currencyMap.get(currency);
-	}
-
 }