CXF/ JAX-RS : Return Custom response from interceptor

Question

We need to return custom error code and error message when exception occurs during REST invocation. We have created a exception mapper provider, it works well for the exceptions from the application code. However, it doesn't work when exception occurs from the CXF code (e.g. form the CustomValidationInterceptor that I wrote).

For example, if I request with invalid path parameter (e.g invalid phoneNumber). In this case, we need to return a custom error code and error message in JSON format, but it doesn't work even though we have a exception mapper provider created to handle WebApplicationException.

Is there any way to handle exceptions from cxf interceptors and return response to user with something like the following?

{
"errorDetail": {
"errorCode": "404",
"errorMessage": "Bad Request"
}
}

Code Snippet of my CustomValidationInterceptor :

public class CustomValidationInterceptor extends AbstractPhaseInterceptor<Message>{

    public CustomValidationInterceptor() {
        super(Phase.PRE_INVOKE); // Put this interceptor in this phase
    }

    public void handleMessage(Message message) {

        MetadataMap<String, String> metadataMap = (MetadataMap<String, String>) message.get("jaxrs.template.parameters");

        if(null != metadataMap) {
            List<String> list = metadataMap.get("phoneNumber");
            if(null != list) {
                String phoneNumber = list.get(0);
                boolean result = validatePhoneNumber(phoneNumber);
                if(!result){
                    throw new TelusServiceException(Response.status(Response.Status.BAD_REQUEST).build(), 400, "phone number not valid");
                }
            } else {
                throw new TelusServiceException(Response.status(Response.Status.BAD_REQUEST).build(), 400, "phone number not valid");
            }
        } else {
            throw new TelusServiceException(Response.status(Response.Status.BAD_REQUEST).build(), 400, "phone number not valid");
        }
    }

    public boolean validatePhoneNumber(String phoneNumber) {

          Pattern pattern = Pattern.compile("^[1-9]\\d{9}$");
          Matcher matcher = pattern.matcher(phoneNumber);

          if (!matcher.matches()) {
              return false;
          }
          return true;
     }

}

Code Snippet of my Custom Exception Mapper Provider

public class TelusExceptionHandler implements ExceptionMapper<TelusServiceException> {

    public Response toResponse(TelusServiceException exception) {
        return Response.status(exception.getErrorDetail().getErrorCode()).entity(exception.getErrorDetail()).build();
    }

}

Code Snippet of TelusServiceException

public class TelusServiceException extends WebApplicationException{

// constructors and other methods 

    private ErrorDetail errorDetail = null;

        public ErrorDetail getErrorDetail() {
        return errorDetail;
    }

    public void setErrorDetail(ErrorDetail errorDetail) {
        this.errorDetail = errorDetail;
    }

      public TelusServiceException(Response response, int errorCode, String errorMessage) {
        super(response);

        errorDetail = new ErrorDetail();
        errorDetail.setErrorCode(errorCode);
        errorDetail.setErrorMessage(errorMessage);
    }

}

Code Snippet of ErrorDetail class

@XmlRootElement(name="errorDetail")
public class ErrorDetail {

    private int errorCode;
    private String errorMessage;

    @XmlElement(name = "errorCode")
    public int getErrorCode() {
        return errorCode;
    }

    public void setErrorCode(int errorCode) {
        this.errorCode = errorCode;
    }
    @XmlElement(name = "errorMessage")
    public String getErrorMessage() {
        return errorMessage;
    }

    public void setErrorMessage(String errorMessage) {
        this.errorMessage = errorMessage;
    }

}

Answer 1

I found a way to send a custom response from the interceptor but still can't figure out a way to call my CustomExceptionHandler from the interceptor

Code:

public void handleMessage(Message message) {

        MetadataMap<String, String> metadataMap = (MetadataMap<String, String>) message.get("jaxrs.template.parameters");

        if(null != metadataMap) {
            List<String> list = metadataMap.get("phoneNumber");
            if(null != list) {
                String phoneNumber = list.get(0);
                boolean result = validatePhoneNumber(phoneNumber);
                if(!result){
// Create a response object and set it in the message. 
// calling getExchange() will not call your service
                    Response response = Response
                .status(Response.Status.BAD_REQUEST)
                .entity(new ErrorDetail(Response.Status.BAD_REQUEST.getStatusCode(), Response.Status.BAD_REQUEST.toString()))
                .build();
        message.getExchange().put(Response.class, response);
// That's it
                }
            } else {
                Response response = Response
                .status(Response.Status.BAD_REQUEST)
                .entity(new ErrorDetail(Response.Status.BAD_REQUEST.getStatusCode(), Response.Status.BAD_REQUEST.toString()))
                .build();
        message.getExchange().put(Response.class, response);
            }
        } else {
            Response response = Response
                .status(Response.Status.BAD_REQUEST)
                .entity(new ErrorDetail(Response.Status.BAD_REQUEST.getStatusCode(), Response.Status.BAD_REQUEST.toString()))
                .build();
        message.getExchange().put(Response.class, response);
        }
    }

Answer 2

I raised a similar question on the cxf user group, see:

http://cxf.547215.n5.nabble.com/Handling-exceptions-in-a-JAX-RS-fault-interceptor-when-using-Local-Transport-td5733958.html

I ended up replacing my interceptors with ContainerRequestFilter and ContainerResponseFilter and then the Exception Mapper happily handled both application exceptions and exceptions thrown from the Filter.

Hope this helps.