[CAMEL-21478] camel-rest-openapi: Input and output types binding to java classes using $ref or title of the schema

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 4.8.0, 4.8.1
• Fix Version/s: 4.10.0
• Component/s: camel-rest-openapi
• Estimated Complexity: Unknown
• Assignee: Unassigned
• Reporter: Chamodya Dias
• Created: 5 days ago 13:20
• Updated: 4 days ago 09:10

Description

Currently, camel resolves the Java class names for RestBindingConfiguration from Schema XML attribute.

Implemented at: org.apache.camel.component.rest.openapi.RestOpenApiProcessor

```
private RestBindingConfiguration createRestBindingConfiguration(Operation o) throws Exception {
...
...
Schema s = m.getValue().getSchema();
// $ref is null, so we need to know the schema name via XML
if (s != null && s.getXml() != null) {
String ref = s.getXml().getName();
...
```
 
But the documentation says Camel can resolve the schema from the schema name: https://camel.apache.org/manual/rest-dsl-openapi.html#_binding_to_pojo_classes
 
This improvement suggests adding an `else-if` condition that to above code that uses `$ref` to resolve the schema name if available and another `else-if` condition that uses the `title` attribute (https://github.com/OAI/OpenAPI-Specification/blob/3.0.2/versions/3.0.2.md#schema-object) of the schema to get the class name if available.
 
Also, the current implementation doesn't resolve class names when using the `requestBodies` component directly in the OAS. It only uses `content` attribute.
 
example:
```
requestBody:
  $ref: '#/components/requestBodies/createProduct'
```
This improvement suggests the capability to add this also.