Swagger generated code now silently ignores invalid values for enumerated types

Description

Swagger generated code now silently ignores invalid values for enumerated types.

We used to have 400 exception which was perfect:
HTTP/1.1 400 Bad Request
X-Powered-By: Servlet/3.0
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, DELETE, PUT
Access-Control-Allow-Headers: Content-Type
Content-Length: 533
Content-Type: text/plain
Content-Language: en-AU
Connection: Close
Date: Thu, 03 Nov 2016 05:38:45 GMT

The supplied JSON was not well formed: Can not construct instance of.....

Swagger-codegen version

2.2.2-SNAPSHOT

Command line used for generation

Java, Jersey 2, jaxrs

Steps to reproduce

that code is the issue I think.
@JsonCreator
public static XXXEnum fromValue(String text) {
for (XXXEnum b : XXXEnum.values()) {
if (String.valueOf(b.value).equals(text)) {
return b;
}
}
return null;
}

Suggest a Fix

I think this is a key functionality that cannot be changed. Several projects relying on that validation
Please revert the changes.

Start with the Java, Jersey 2, jaxrs generation path and the generated XXXEnum.fromValue(String) method shown in the issue. Reproduce an invalid enumerated value and trace how the generated server handles the returned value. Done means invalid enum input is rejected again with an HTTP 400 response, with coverage added where the generation behavior is tested.