[BUG][JAVA] resteasy library - defaultCookieMap not used in ApiClient

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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When Generating classes via the maven plugin and the resteasy library there is no way to set default cookies via the ApiClient as the defaultCookieMap field is not used.

In the invokeAPI function is generated with a block of code that seems like it's supposed to implement default cookies but instead of the aforementioned defaultCookieMap defaultHeaderMap is used:

    for (Entry<String, String> defaultCookieEntry: defaultHeaderMap.entrySet()) {
      if (!cookieParams.containsKey(defaultCookieEntry.getKey())) {
        String value = defaultCookieEntry.getValue();
        if (value != null) {
          invocationBuilder = invocationBuilder.cookie(defaultCookieEntry.getKey(), value);
        }
      }
    }

Other java generator libraries like jersey2 put defaultCookieMap here like they're supposed to.

openapi-generator version

6.2.1, 5.1.1 and some others were tested.
seems to affect every major semi recent build.

Generation Details

pom plugin configuration:

<plugin>
<groupId>org.openapitools</groupId>
<artifactId>openapi-generator-maven-plugin</artifactId>
<version>6.2.1</version>
<executions>
	<execution>
		<goals>
			<goal>generate</goal>
		</goals>
		<configuration>
			<inputSpec>http://localhost:8083/service/openapi.json</inputSpec>
			<generatorName>java</generatorName>

			<configOptions>
				<dateLibrary>java8</dateLibrary>
				<useBeanValidation>true</useBeanValidation>
			</configOptions>

			<library>resteasy</library>
		</configuration>
	</execution>
</executions>
</plugin>

generation is done by executing maven clean compile with profile generate-model in eclipse

Steps to reproduce

1. take any openapi spec file
2. generate the client code via the maven plugin, java generator and resteasy library
3. done

Even your own resteasy example has that issue at line 658

Suggest a fix

The ApiClient.mustache seems to be correct and other libraries like jersey2 don't make this mistake so I think the resteasy library code needs to be checked. I think this is just a copy/ paste error

Start with the resteasy generated sample at samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/ApiClient.java around line 658, then inspect ApiClient.mustache and compare the corresponding jersey2 code. Regenerate a Java client with the resteasy library and verify that default cookies are applied from defaultCookieMap rather than defaultHeaderMap.