🛡️implement exception handling across microservices

common/src/main/java/exceptionhandler/business/CustomerException.java

@@ -0,0 +1,10 @@
+package exceptionhandler.business;
+
+import exceptionhandler.core.BaseException;
+
+public class CustomerException extends BaseException {
+    public CustomerException(String message) {
+        super(message);
+    }
+}
+

common/src/main/java/exceptionhandler/business/NotificationException.java

@@ -0,0 +1,9 @@
+package exceptionhandler.business;
+
+import exceptionhandler.core.BaseException;
+
+public class NotificationException extends BaseException {
+    public NotificationException(String message) {
+        super(message);
+    }
+}

common/src/main/java/exceptionhandler/business/OrderException.java

@@ -0,0 +1,10 @@
+package exceptionhandler.business;
+
+import exceptionhandler.core.BaseException;
+
+public class OrderException extends BaseException {
+    public OrderException(String message) {
+        super(message);
+    }
+}
+

common/src/main/java/exceptionhandler/business/PaymentException.java

@@ -0,0 +1,10 @@
+package exceptionhandler.business;
+
+import exceptionhandler.core.BaseException;
+
+public class PaymentException extends BaseException {
+    public PaymentException(String message) {
+        super(message);
+    }
+}
+

common/src/main/java/exceptionhandler/business/ProductException.java

@@ -0,0 +1,9 @@
+package exceptionhandler.business;
+
+import exceptionhandler.core.BaseException;
+
+public class ProductException extends BaseException {
+    public ProductException(String message) {
+        super(message);
+    }
+}

common/src/main/java/exceptionhandler/core/BadRequestException.java

@@ -0,0 +1,7 @@
+package exceptionhandler.core;
+
+public class BadRequestException extends BaseException {
+    public BadRequestException(String message) {
+        super(message);
+    }
+}

common/src/main/java/exceptionhandler/core/BaseException.java

@@ -0,0 +1,7 @@
+package exceptionhandler.core;
+
+public abstract class BaseException extends RuntimeException {
+    public BaseException(String message) {
+        super(message);
+    }
+}

common/src/main/java/exceptionhandler/core/DuplicateResourceException.java

@@ -0,0 +1,8 @@
+package exceptionhandler.core;
+
+public class DuplicateResourceException extends BaseException {
+    public DuplicateResourceException(String message) {
+        super(message);
+    }
+}
+

common/src/main/java/exceptionhandler/core/ResourceNotFoundException.java

@@ -0,0 +1,7 @@
+package exceptionhandler.core;
+
+public class ResourceNotFoundException extends BaseException {
+    public ResourceNotFoundException(String message) {
+        super(message);
+    }
+}

common/src/main/java/exceptionhandler/core/ValidationException.java

@@ -0,0 +1,17 @@
+package exceptionhandler.core;
+
+import exceptionhandler.payload.ValidationError;
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+public class ValidationException extends BaseException {
+    private final List<ValidationError> errors;
+
+    public ValidationException(String message, List<ValidationError> errors) {
+        super(message);
+        this.errors = errors;
+    }
+}
+

common/src/main/java/exceptionhandler/handler/RestResponseEntityExceptionHandler.java

@@ -0,0 +1,115 @@
+package exceptionhandler.handler;
+
+import exceptionhandler.business.CustomerException;
+import exceptionhandler.business.NotificationException;
+import exceptionhandler.business.OrderException;
+import exceptionhandler.business.PaymentException;
+import exceptionhandler.business.ProductException;
+import exceptionhandler.core.BaseException;
+import exceptionhandler.core.DuplicateResourceException;
+import exceptionhandler.core.ResourceNotFoundException;
+import exceptionhandler.core.ValidationException;
+import exceptionhandler.payload.ErrorCode;
+import exceptionhandler.payload.ErrorDetails;
+import exceptionhandler.payload.ValidationError;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@RestControllerAdvice
+@Slf4j
+public class RestResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler(ResourceNotFoundException.class)
+    @ResponseStatus(HttpStatus.NOT_FOUND)
+    public ResponseEntity<ErrorDetails> handleResourceNotFoundException(
+            ResourceNotFoundException ex, WebRequest request) {
+        return buildErrorResponse(ex.getMessage(),
+                ErrorCode.RESOURCE_NOT_FOUND,
+                HttpStatus.NOT_FOUND,
+                request);
+    }
+
+    @ExceptionHandler(ValidationException.class)
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    public ResponseEntity<ErrorDetails> handleValidationException(
+            ValidationException ex, WebRequest request) {
+        return buildErrorResponse(ex.getMessage(),
+                ErrorCode.VALIDATION_FAILED,
+                HttpStatus.BAD_REQUEST,
+                request,
+                ex.getErrors());
+    }
+
+    @ExceptionHandler(DuplicateResourceException.class)
+    @ResponseStatus(HttpStatus.CONFLICT)
+    public ResponseEntity<ErrorDetails> handleDuplicateResourceException(
+            DuplicateResourceException ex, WebRequest request) {
+        return buildErrorResponse(ex.getMessage(),
+                ErrorCode.DUPLICATE_RESOURCE,
+                HttpStatus.CONFLICT,
+                request);
+    }
+
+    @ExceptionHandler({
+            CustomerException.class,
+            OrderException.class,
+            PaymentException.class,
+            ProductException.class,
+            NotificationException.class
+    })
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    public ResponseEntity<ErrorDetails> handleBusinessExceptions(
+            BaseException ex, WebRequest request) {
+        return buildErrorResponse(ex.getMessage(),
+                ErrorCode.BAD_REQUEST,
+                HttpStatus.BAD_REQUEST,
+                request);
+    }
+
+    @ExceptionHandler(Exception.class)
+    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+    public ResponseEntity<ErrorDetails> handleAllUncaughtException(
+            Exception ex, WebRequest request) {
+        return buildErrorResponse(ex.getMessage(),
+                ErrorCode.INTERNAL_ERROR,
+                HttpStatus.INTERNAL_SERVER_ERROR,
+                request);
+    }
+
+    private ResponseEntity<ErrorDetails> buildErrorResponse(
+            String message,
+            ErrorCode errorCode,
+            HttpStatus status,
+            WebRequest request) {
+        return buildErrorResponse(message, errorCode, status, request, null);
+    }
+
+    private ResponseEntity<ErrorDetails> buildErrorResponse(
+            String message,
+            ErrorCode errorCode,
+            HttpStatus status,
+            WebRequest request,
+            List<ValidationError> errors) {
+
+        ErrorDetails errorDetails = ErrorDetails.builder()
+                .timestamp(LocalDateTime.now())
+                .code(errorCode.getCode())
+                .message(message)
+                .path(((ServletWebRequest) request).getRequest().getRequestURI())
+                .errors(errors)
+                .build();
+
+        return new ResponseEntity<>(errorDetails, status);
+    }
+}
+

common/src/main/java/exceptionhandler/payload/ErrorCode.java

@@ -0,0 +1,20 @@
+package exceptionhandler.payload;
+
+public enum ErrorCode {
+    RESOURCE_NOT_FOUND("ERR_001"),
+    VALIDATION_FAILED("ERR_002"),
+    DUPLICATE_RESOURCE("ERR_003"),
+    BAD_REQUEST("ERR_004"),
+    INTERNAL_ERROR("ERR_005");
+
+    private final String code;
+
+    ErrorCode(String code) {
+        this.code = code;
+    }
+
+    public String getCode() {
+        return code;
+    }
+}
+

common/src/main/java/exceptionhandler/payload/ErrorDetails.java

@@ -0,0 +1,18 @@
+package exceptionhandler.payload;
+
+import lombok.Builder;
+import lombok.Getter;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Getter
+@Builder
+public class ErrorDetails {
+    private LocalDateTime timestamp;
+    private String code;
+    private String message;
+    private String path;
+    private List<ValidationError> errors;
+}
+

common/src/main/java/exceptionhandler/payload/ValidationError.java

@@ -0,0 +1,12 @@
+package exceptionhandler.payload;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class ValidationError {
+    private String field;
+    private String message;
+}
+

customer/src/main/java/dev/nano/customer/CustomerConstant.java

@@ -2,5 +2,8 @@
 
 public class CustomerConstant {
     public static final String CUSTOMER_URI_REST_API = "/api/v1/customers";
-    public static final String CUSTOMER_NOT_FOUND_EXCEPTION = "User not found";
+    public static final String CUSTOMER_NOT_FOUND = "Customer with ID %d not found";
+    public static final String CUSTOMER_EMAIL_EXISTS = "Customer with email %s already exists";
+    public static final String NO_CUSTOMERS_FOUND = "No customers found";
 }
+

customer/src/main/java/dev/nano/customer/CustomerController.java

@@ -4,13 +4,15 @@
 import dev.nano.clients.order.OrderResponse;
 import dev.nano.clients.payment.PaymentRequest;
 import dev.nano.clients.payment.PaymentResponse;
+import jakarta.validation.Valid;
 import lombok.AllArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.http.HttpStatus;
-import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
+import java.util.List;
+
 import static dev.nano.customer.CustomerConstant.CUSTOMER_URI_REST_API;
 
 
@@ -21,53 +23,54 @@ public class CustomerController {
 
     private final CustomerService customerService;
 
-    @GetMapping(
-            path = "/{customerId}",
-            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE}
-    )
-    public ResponseEntity<CustomerDTO> getCustomer(@PathVariable("customerId") Long customerId)
-            throws CustomerNotFoundException {
+    @GetMapping(path = "/{customerId}")
+    public ResponseEntity<CustomerDTO> getCustomer(@PathVariable("customerId") Long customerId) {
+        log.info("Retrieving customer with ID: {}", customerId);
+        return ResponseEntity.ok(customerService.getCustomer(customerId));
+    }
 
-        log.info("Retrieving customer with id {}", customerId);
-        return new ResponseEntity<>(
-            customerService.getCustomer(customerId),
-            HttpStatus.OK
-        );
+    @GetMapping
+    public ResponseEntity<List<CustomerDTO>> getAllCustomers() {
+        log.info("Retrieving all customers");
+        return ResponseEntity.ok(customerService.getAllCustomers());
     }
 
-    @PostMapping(
-            path = "/add",
-            consumes={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE},
-            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE}
-    )
-    public ResponseEntity<CustomerDTO> createNewCustomer(@RequestBody CustomerDTO customerDTO) {
-        log.info("Add new customer {}", customerDTO);
+    @PostMapping("/add")
+    public ResponseEntity<CustomerDTO> createCustomer(@Valid @RequestBody CustomerDTO customerDTO) {
+        log.info("Creating new customer: {}", customerDTO);
         return new ResponseEntity<>(
-            customerService.createCustomer(customerDTO),
-            HttpStatus.CREATED
+                customerService.createCustomer(customerDTO),
+                HttpStatus.CREATED
         );
     }
 
-    @PostMapping(
-            path = "/orders",
-            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE}
-    )
-    public ResponseEntity<OrderResponse> customerOrders(@RequestBody OrderRequest orderRequest) {
+    @PutMapping("/{customerId}")
+    public ResponseEntity<CustomerDTO> updateCustomer(
+            @PathVariable Long customerId,
+            @Valid @RequestBody CustomerDTO customerDTO) {
+        log.info("Updating customer with ID {}: {}", customerId, customerDTO);
+        return ResponseEntity.ok(customerService.updateCustomer(customerId, customerDTO));
+    }
+
+    @DeleteMapping("/{customerId}")
+    public ResponseEntity<Void> deleteCustomer(@PathVariable Long customerId) {
+        log.info("Deleting customer with ID: {}", customerId);
+        customerService.deleteCustomer(customerId);
+        return ResponseEntity.noContent().build();
+    }
 
-        log.info("Customer orders {}", orderRequest);
+    @PostMapping("/orders")
+    public ResponseEntity<OrderResponse> customerOrders(@Valid @RequestBody OrderRequest orderRequest) {
+        log.info("Processing order for customer: {}", orderRequest);
         return new ResponseEntity<>(
-            customerService.customerOrders(orderRequest),
-            HttpStatus.CREATED
+                customerService.customerOrders(orderRequest),
+                HttpStatus.CREATED
         );
     }
 
-    @PostMapping(
-            path = "/payment",
-            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_VALUE}
-    )
-    public ResponseEntity<PaymentResponse> customerPayment(@RequestBody PaymentRequest paymentRequest) {
-
-        log.info("Customer payment {}", paymentRequest);
+    @PostMapping("/payment")
+    public ResponseEntity<PaymentResponse> customerPayment(@Valid @RequestBody PaymentRequest paymentRequest) {
+        log.info("Processing payment for customer: {}", paymentRequest);
         return new ResponseEntity<>(
                 customerService.customerPayment(paymentRequest),
                 HttpStatus.CREATED