always use @JacksonXmlElementWrapper and read xml data from reference…

Created by: jzrebiec

Hello All,

This pull request adds:

• always writes JacksonXmlElementWrapper even if xml.wrapped is false, because useWrapping is true from Jackson 2.1
• get xml properties from referenced schema.

Here is example of yaml:

openapi: 3.0.0
info:
  title: API
  version: 1.0.0

paths:
  /:
    post:
      requestBody:
        required: true
        content:
          application/xml:
            schema:
              $ref: '#/components/schemas/Request'
      responses:
        '200':
          description: OK

components:
  schemas:
    Request:
      type: object
      properties:
        simpleAttribute:
          type: string
          xml:
            attribute: true
            name: ATTR
        refAttribute:
          $ref: '#/components/schemas/RefAttribute'
        simpleNode:
          type: object
          properties:
            prop1:
              type: string
            prop2:
              type: string
          xml:
            name: NODE
        refNode:
          $ref: '#/components/schemas/RefNode'
        simpleArray:
          type: array
          items:
            type: string
            xml:
              name: ARR_ITEM
        simpleWrappedArray:
          type: array
          items:
            type: string
            xml:
              name: ARR_ITEM
          xml:
            wrapped: true
            name: WRAPPED_ARRAY
        nodeArray:
          type: array
          items:
            $ref: '#/components/schemas/RefNode'
        wrappedNodeArray:
          type: array
          items:
            $ref: '#/components/schemas/RefNode'
          xml:
            wrapped: true
            name: WRAPPED_NODE_ARRAY
      xml:
        name: Request

    RefAttribute:
      type: string
      enum: [A, B, C]
      xml:
        name: REF_ATTR
        attribute: true

    RefNode:
      type: object
      properties:
        prop1:
          type: string
        prop2:
          type: string
      xml:
        name: REF_NODE

   

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