[JAVA][SPRING BOOT] Feature generic Error code stubs in spring boot

Description

Please add error code stubs for spring boot code generation for the various error responses specified in the swagger json. Currently, it just adds the import statements for the models used in the error responses.

Swagger-codegen version

version 2.2.2

Swagger declaration file content or url

The code generator should add something like the following from the Uber api example

For the default response to return an Error model object.

paths:
  /estimates/time::
    get:
      responses:
        default:
          description: Unexpected error
          schema:
            $ref: '#/definitions/Error'

In EstimatesApi.java add a method to return BAD_REQUEST.

	@ExceptionHandler(TypeMismatchException.class)
	@ResponseStatus(value = HttpStatus.BAD_REQUEST)
	@ResponseBody
	public Error handleTypeMismatchException(HttpServletRequest req, TypeMismatchException ex);

	@Override
	public Error handleTypeMismatchException(HttpServletRequest req, TypeMismatchException ex)
		return new Error();
	}

Then throw the TypeMismatchException in the estimatesTimeGet method.

Command line used for generation

I did not look into the command line.

Steps to reproduce

Not a bug.

Related issues

Don't know if this has been suggested before.

Suggest a Fix

Side feature may be a way to map exception classes to error responses in the swagger.json file. See above code as a loose framework of the idea.

Start with the Swagger JSON response definitions and the generated EstimatesApi.java example described in the issue. Inspect the Spring Boot server generator templates and determine how default and typed error responses should map to exception handlers; done means generated code includes the requested error stubs and throws or handles the corresponding exceptions consistently.