[BUG][java] JavaSpring Date PathParams serialize in the wrong format in

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

Date parameters in the path should be serialized according to RFC3339 (YYYY-MM-DD) but are actually serialized as M/D/YY. This was already addressed in the queryParams template by specifying a DateTimeFormat. The same logic should be used in the pathParams template.

openapi-generator version

Using OpenAPI Generator 5.3.0

OpenAPI declaration file content or url

components:
  parameters:
    MyDateParam:
      name: myDate
      in: path
      required: true
      type: string
      format: date

Generation Details

Using the following settings:

• module: JavaSpring
• library: spring-cloud
• dateLibrary: java8

Steps to reproduce

Serialize a pathParam date using a Feign client. The resulting path will contain an incorrect date.

Suggest a fix

The same issue was already addressed in the queryParams template. Applying it to the pathParams template resolves the issue. I'll submit a PR shortly.

Start with the JavaSpring spring-cloud pathParams template and compare it with the existing queryParams template's date handling. Generate a Feign client from the supplied OpenAPI declaration using dateLibrary java8; done when a path date is serialized as RFC3339 YYYY-MM-DD rather than M/D/YY.