OperationParameterReader does not process optional path parameters correctly

[raphw]

When a Spring controller offers an optional parameter such as in:

@RequestMapping({"/foo", "/foo/{bar}"})
public void foo(@PathVariable(value = "bar", required = false) String bar) {
  if (bar == null) { ... } else { ... }
}

Springfox will correctly create two mappings for /foo and /foo/{bar} but define the bar parameter as required for both mappings. I think the problem lies in the OperationParameterReader which should detect that the parameter for bar should be ignored for the mapping of /foo.

I think that a solution could be as simple as adding a condition to the OperationParameterReader:shouldIgnore method that looks something similar to:

if (parameter.hasParameterAnnotation(PathVariable.class)
  && !parameter.getAnnotation(PathVariable.class).required()
  && !context.requestMappingPattern().contains("{" + methodParameter.defaultName() + "}") {
    return true;
}

This way any parameter would be suppressed that is:

1. Representing a path variable
2. Is not required
3. Is not part of the mapped path.

[dilipkrish]

There is an underlying assumption that PathVariables are always required. Thanks for catching this!