在球衣休息服务中返回错误列表

Question

In our project we are using rest service(Jersey). In one of the requirement I would like to return a list of missing mandatory parameters back to the client. Right now I am using exception mapper which can return a single error message,

public class MandatoryParameterMissingException extends RuntimeException {

    private static final long serialVersionUID = 1L;


    public MandatoryParameterMissingException(String message) {
        super(message);
    }


public class MandatoryParamMissingExceptionMapper implements ExceptionMapper<MandatoryParameterMissingException> {

    @Override
    public Response toResponse(MandatoryParameterMissingException ex) {
        ErrorMessage errorMessage = new ErrorMessage(ex.getMessage(), 404, "Document source:todo");
        return Response.status(Status.NOT_FOUND)
                .entity(errorMessage)
                .build();
    }

private String errorMessage;
    private int errorCode;
    private String documentation;

    public ErrorMessage() {

    }

    public ErrorMessage(String errorMessage, int errorCode, String documentation) {
        super();
        this.errorMessage = errorMessage;
        this.errorCode = errorCode;
        this.documentation = documentation;
    }

..getter setters

If I find any missing mandatory params, right now I am doing something like,

if (emailID == null) {
            throw new MandatoryParameterMissingException("Email id is missing");
        }

Could some one please suggest What is the best way to enhance this to take a list of error messages and pass it back to the client?

Answer 1

For this issue i created a class called ValidationException. A ValidationException contains a list of ValidationError.

There are different kind of ValidationError, for example OutOfRangeError, MandatoryParameterError and whatever you need. A ValidationError always contains specific attributes (all what the client needs to create a meaningful messagetext for the user) => A MandatoryParameterError just the name of the field, an OutOfRangeError the name of the field and the allowed range.

On serverside there are validators (in a common package, so the client could do the validation itself)... the validators are creating ValidationErrors during the validation of your data. If there are validation errors, a ValidationException is thrown. That's it. I can give you some codesnippets...