[FFM-11459] - Downgrade OpenAPI plugin to allow broader range of SpringBoot compatibility (#191)

What
Downgrade the OpenAPI plugin to 4.3.1

Why
Newer 5.x.x plugins are generating code that use newer okhttp APIs. This makes it difficult
for customers using older versions of SpringBoot to downgrade because older okhttp versions
don't offer these methods. This causes a missing method exception on startup.

Testing
SDK smoke tested against the following SpringBoot releases

2.2.13.RELEASE	3.14.9  14-Jan-21
2.3.12.RELEASE	3.14.9  10-Jun-21
2.4.13 	        3.14.9  18-Nov-21
2.5.12 	        3.14.9  31-Mar-22
2.5.15	        3.14.9  18-May-23
2.6.15	        3.14.9  18-May-23
2.7.18	        4.9.3   23-Nov-23
3.0.13          4.10.0  23-Nov-23
3.1.11          4.10.0  18-Apr-23
3.2.5           4.12.0  23-Nov-23
3.3.0-RC1       4.12.0  19-Apr-24

Author: andybharness

settings.gradle

@@ -32,7 +32,9 @@ dependencyResolutionManagement {
             library('harness.ff.sdk', 'io.harness', 'ff-java-server-sdk').versionRef('sdk')
 
             // plugins
-            version('openapi.generator', '5.4.0')
+            // do not upgrade openapi, doing so will break compatibility with customers using SpringBoot 2.5.x
+            // (newer 5.x.x generators use APIs not present in okhttp 3.14.9)
+            version('openapi.generator', '4.3.1')
             version('spotless', '6.23.3')
             version('depsize', '0.2.0')
             version('spotbugs', '6.0.4')

src/main/java/io/harness/cf/client/connector/HarnessConnector.java

@@ -98,7 +98,7 @@ ApiClient makeApiClient(int retryBackOfDelay) {
   private Response reauthInterceptor(Interceptor.Chain chain) throws IOException {
     final Request request =
         chain.request().newBuilder().addHeader("X-Request-ID", getRequestID()).build();
-    log.debug("403 interceptor check: requesting url {}", request.url().url());
+    log.debug("Checking for 403 in interceptor: requesting url {}", request.url().url());
 
     Response response = chain.proceed(request);