Piggy-backing on BasicErrorController

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.BasicErrorController;
import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.dao.DataIntegrityViolationException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.ServletRequestAttributes;

@ControllerAdvice
public class ExceptionHandlerController extends BasicErrorController {

    private Logger logger = LoggerFactory.getLogger(getClass());

    private final ErrorAttributes errorAttributes;

    @Autowired
    public ExceptionHandlerController(ErrorAttributes errorAttributes) {
        super(errorAttributes);
        this.errorAttributes = errorAttributes;
    }

    // add ExceptionHandlers as needed...

    @ExceptionHandler(DataIntegrityViolationException.class)
    public ResponseEntity<Map<String, Object>> dataIntegrityViolationError(Throwable t, HttpServletRequest request) {
        return buildResponse(t, request, HttpStatus.BAD_REQUEST);
    }

    protected ResponseEntity<Map<String, Object>> buildResponse(Throwable t, HttpServletRequest request, HttpStatus status) {
        logger.error("Could not process request!", t);
        RequestAttributes requestAttributes = new ServletRequestAttributes(request);

        // only show stack trace if trace is provided as a URL query parameter
        Map<String, Object> body = errorAttributes.getErrorAttributes(requestAttributes, getTraceParameter(request));

        body.put("status", status.value());
        body.put("error", status.getReasonPhrase());
        body.put("path", request.getRequestURI());
        return new ResponseEntity<Map<String, Object>>(body, status);
    }

    private boolean getTraceParameter(HttpServletRequest request) {
        String parameter = request.getParameter("trace");
        if (parameter == null) {
            return false;
        }
        return !"false".equals(parameter.toLowerCase());
    }

}