Task 27 : Define GlobalExceptionHandler in userservice

userservice/src/main/java/com/springbootmicroservices/userservice/exception/handler/GlobalExceptionHandler.java

@@ -0,0 +1,194 @@
+package com.springbootmicroservices.userservice.exception.handler;
+
+import com.springbootmicroservices.userservice.exception.*;
+import com.springbootmicroservices.userservice.model.common.CustomError;
+import jakarta.validation.ConstraintViolationException;
+import org.apache.commons.lang3.StringUtils;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Global exception handler named {@link GlobalExceptionHandler} for handling various types of exceptions in the application.
+ */
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    /**
+     * Handles MethodArgumentNotValidException thrown when validation on an argument annotated with @Valid fails.
+     *
+     * @param ex The MethodArgumentNotValidException instance.
+     * @return ResponseEntity with CustomError containing details of validation errors.
+     */
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    protected ResponseEntity<Object> handleMethodArgumentNotValid(final MethodArgumentNotValidException ex) {
+
+        List<CustomError.CustomSubError> subErrors = new ArrayList<>();
+
+        ex.getBindingResult().getAllErrors().forEach(
+                error -> {
+                    String fieldName = ((FieldError) error).getField();
+                    String message = error.getDefaultMessage();
+                    subErrors.add(
+                            CustomError.CustomSubError.builder()
+                                    .field(fieldName)
+                                    .message(message)
+                                    .build()
+                    );
+                }
+        );
+
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.BAD_REQUEST)
+                .header(CustomError.Header.VALIDATION_ERROR.getName())
+                .message("Validation failed")
+                .subErrors(subErrors)
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.BAD_REQUEST);
+
+    }
+
+    /**
+     * Handles ConstraintViolationException thrown when a bean validation constraint is violated.
+     *
+     * @param constraintViolationException The ConstraintViolationException instance.
+     * @return ResponseEntity with CustomError containing details of constraint violations.
+     */
+    @ExceptionHandler(ConstraintViolationException.class)
+    protected ResponseEntity<Object> handlePathVariableErrors(final ConstraintViolationException constraintViolationException) {
+
+        List<CustomError.CustomSubError> subErrors = new ArrayList<>();
+        constraintViolationException.getConstraintViolations()
+                .forEach(constraintViolation ->
+                        subErrors.add(
+                                CustomError.CustomSubError.builder()
+                                        .message(constraintViolation.getMessage())
+                                        .field(StringUtils.substringAfterLast(constraintViolation.getPropertyPath().toString(), "."))
+                                        .value(constraintViolation.getInvalidValue() != null ? constraintViolation.getInvalidValue().toString() : null)
+                                        .type(constraintViolation.getInvalidValue().getClass().getSimpleName())
+                                        .build()
+                        )
+                );
+
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.BAD_REQUEST)
+                .header(CustomError.Header.VALIDATION_ERROR.getName())
+                .message("Constraint violation")
+                .subErrors(subErrors)
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.BAD_REQUEST);
+
+    }
+
+    /**
+     * Handles RuntimeException thrown for general runtime exceptions.
+     *
+     * @param runtimeException The RuntimeException instance.
+     * @return ResponseEntity with CustomError containing details of the runtime exception.
+     */
+    @ExceptionHandler(RuntimeException.class)
+    protected ResponseEntity<?> handleRuntimeException(final RuntimeException runtimeException) {
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.NOT_FOUND)
+                .header(CustomError.Header.API_ERROR.getName())
+                .message(runtimeException.getMessage())
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.NOT_FOUND);
+    }
+
+    /**
+     * Handles PasswordNotValidException thrown when a password is not valid.
+     *
+     * @param ex The PasswordNotValidException instance.
+     * @return ResponseEntity with CustomError containing details of the exception.
+     */
+    @ExceptionHandler(PasswordNotValidException.class)
+    protected ResponseEntity<Object> handlePasswordNotValidException(final PasswordNotValidException ex) {
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.BAD_REQUEST)
+                .header(CustomError.Header.API_ERROR.getName())
+                .message(ex.getMessage())
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.BAD_REQUEST);
+    }
+
+    /**
+     * Handles TokenAlreadyInvalidatedException thrown when a token is already invalidated.
+     *
+     * @param ex The TokenAlreadyInvalidatedException instance.
+     * @return ResponseEntity with CustomError containing details of the exception.
+     */
+    @ExceptionHandler(TokenAlreadyInvalidatedException.class)
+    protected ResponseEntity<Object> handleTokenAlreadyInvalidatedException(final TokenAlreadyInvalidatedException ex) {
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.BAD_REQUEST)
+                .header(CustomError.Header.API_ERROR.getName())
+                .message(ex.getMessage())
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.BAD_REQUEST);
+    }
+
+    /**
+     * Handles UserAlreadyExistException thrown when a user already exists.
+     *
+     * @param ex The UserAlreadyExistException instance.
+     * @return ResponseEntity with CustomError containing details of the exception.
+     */
+    @ExceptionHandler(UserAlreadyExistException.class)
+    protected ResponseEntity<Object> handleUserAlreadyExistException(final UserAlreadyExistException ex) {
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.CONFLICT)
+                .header(CustomError.Header.API_ERROR.getName())
+                .message(ex.getMessage())
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.CONFLICT);
+    }
+
+    /**
+     * Handles UserNotFoundException thrown when a user is not found.
+     *
+     * @param ex The UserNotFoundException instance.
+     * @return ResponseEntity with CustomError containing details of the exception.
+     */
+    @ExceptionHandler(UserNotFoundException.class)
+    protected ResponseEntity<Object> handleUserNotFoundException(final UserNotFoundException ex) {
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.NOT_FOUND)
+                .header(CustomError.Header.API_ERROR.getName())
+                .message(ex.getMessage())
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.NOT_FOUND);
+    }
+
+    /**
+     * Handles UserStatusNotValidException thrown when a user status is not valid.
+     *
+     * @param ex The UserStatusNotValidException instance.
+     * @return ResponseEntity with CustomError containing details of the exception.
+     */
+    @ExceptionHandler(UserStatusNotValidException.class)
+    protected ResponseEntity<Object> handleUserStatusNotValidException(final UserStatusNotValidException ex) {
+        CustomError customError = CustomError.builder()
+                .httpStatus(HttpStatus.BAD_REQUEST)
+                .header(CustomError.Header.API_ERROR.getName())
+                .message(ex.getMessage())
+                .build();
+
+        return new ResponseEntity<>(customError, HttpStatus.BAD_REQUEST);
+    }
+
+
+}