GlobalExceptionHandler.java

package com.b2b.ecommerce.exception;

import com.b2b.ecommerce.dto.ErrorResponse;
import jakarta.servlet.http.HttpServletRequest;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.time.LocalDateTime;
import java.util.List;

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleResourceNotFound(
            ResourceNotFoundException ex,
            HttpServletRequest request) {
        ErrorResponse error = ErrorResponse.builder()
            .timestamp(LocalDateTime.now())
            .status(HttpStatus.NOT_FOUND.value())
            .error(HttpStatus.NOT_FOUND.getReasonPhrase())
            .message(ex.getMessage())
            .path(request.getRequestURI())
            .build();

        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);
    }

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<ErrorResponse> handleValidationErrors(
            MethodArgumentNotValidException ex,
            HttpServletRequest request) {
        List<ErrorResponse.FieldError> fieldErrors = ex.getBindingResult().getFieldErrors().stream()
            .map(fe -> ErrorResponse.FieldError.builder()
                .field(fe.getField())
                .message(fe.getDefaultMessage())
                .build())
            .toList();

        ErrorResponse error = ErrorResponse.builder()
            .timestamp(LocalDateTime.now())
            .status(HttpStatus.BAD_REQUEST.value())
            .error(HttpStatus.BAD_REQUEST.getReasonPhrase())
            .message("Validation failed")
            .path(request.getRequestURI())
            .fieldErrors(fieldErrors)
            .build();

        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(error);
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<ErrorResponse> handleGenericException(
            Exception ex,
            HttpServletRequest request) {
        ErrorResponse error = ErrorResponse.builder()
            .timestamp(LocalDateTime.now())
            .status(HttpStatus.INTERNAL_SERVER_ERROR.value())
            .error(HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase())
            .message("An unexpected error occurred")
            .path(request.getRequestURI())
            .build();

        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(error);
    }
}