Prevent ApiClient from creating a new HttpClient if one already exists

Author: chris-koo

basyx.common/basyx.client/src/main/java/org/eclipse/digitaltwin/basyx/client/internal/ApiClient.java

@@ -83,6 +83,7 @@ public class ApiClient {
   private Consumer<HttpResponse<String>> asyncResponseInterceptor;
   private Duration readTimeout;
   private Duration connectTimeout;
+  private HttpClient httpClient;
 
   private static String valueToString(Object value) {
     if (value == null) {
@@ -190,6 +191,7 @@ public ApiClient() {
     connectTimeout = null;
     responseInterceptor = null;
     asyncResponseInterceptor = null;
+    this.httpClient = this.builder.build();
   }
 
   /**
@@ -208,6 +210,7 @@ public ApiClient(HttpClient.Builder builder, ObjectMapper mapper, String baseUri
     connectTimeout = null;
     responseInterceptor = null;
     asyncResponseInterceptor = null;
+    this.httpClient = this.builder.build();
   }
 
   protected ObjectMapper createDefaultObjectMapper() {
@@ -249,6 +252,7 @@ public void updateBaseUri(String baseUri) {
    */
   public ApiClient setHttpClientBuilder(HttpClient.Builder builder) {
     this.builder = builder;
+    this.httpClient = null;
     return this;
   }
 
@@ -260,7 +264,10 @@ public ApiClient setHttpClientBuilder(HttpClient.Builder builder) {
    * @return The HTTP client.
    */
   public HttpClient getHttpClient() {
-    return builder.build();
+    if (httpClient == null) {
+      httpClient = builder.build();
+    }
+    return httpClient;
   }
 
   /**