chore: Make api clients auto-closing.

pom.xml

@@ -158,7 +158,6 @@
       <artifactId>jspecify</artifactId>
       <version>1.0.0</version>
     </dependency>
-    <!-- kotlin std lib (needed for okhttp3)-->
     <dependency>
       <groupId>org.jetbrains.kotlin</groupId>
       <artifactId>kotlin-stdlib-jdk8</artifactId>

src/main/java/com/google/genai/ApiClient.java

@@ -52,7 +52,7 @@
 
 /** Interface for an API client which issues HTTP requests to the GenAI APIs. */
 @InternalApi
-public abstract class ApiClient {
+public abstract class ApiClient implements AutoCloseable {
 
   // {x-version-update-start:google-genai:released}
   private static final String SDK_VERSION = "1.40.0";
@@ -726,4 +726,17 @@ public static void setDefaultBaseUrls(
     ApiClient.geminiBaseUrl = geminiBaseUrl;
     ApiClient.vertexBaseUrl = vertexBaseUrl;
   }
+
+  @Override
+  public void close() {
+    try {
+      httpClient().dispatcher().executorService().shutdown();
+      httpClient().connectionPool().evictAll();
+      if (httpClient().cache() != null) {
+        httpClient().cache().close();
+      }
+    } catch (IOException e) {
+      throw new GenAiIOException("Failed to close the client.", e);
+    }
+  }
 }

src/main/java/com/google/genai/Client.java

@@ -330,15 +330,7 @@ Optional<String> baseUrl() {
   /** Closes the Client instance together with its instantiated http client. */
   @Override
   public void close() {
-    try {
-      apiClient.httpClient().dispatcher().executorService().shutdown();
-      apiClient.httpClient().connectionPool().evictAll();
-      if (apiClient.httpClient().cache() != null) {
-        apiClient.httpClient().cache().close();
-      }
-    } catch (IOException e) {
-      throw new GenAiIOException("Failed to close the client.", e);
-    }
+    apiClient.close();
   }
 
   /**

src/test/java/com/google/genai/ClientTest.java

@@ -188,24 +188,4 @@ public void testSetDefaultBaseUrls() {
     // Reset the base URLs after the test.
     Client.setDefaultBaseUrls(Optional.empty(), Optional.empty());
   }
-
-  @Test
-  public void testCloseClient() throws Exception {
-    // Arrange
-    ApiClient apiClient = mock(ApiClient.class);
-    OkHttpClient httpClient = new OkHttpClient();
-    when(apiClient.httpClient()).thenReturn(httpClient);
-
-    Client client = Client.builder().apiKey(API_KEY).vertexAI(false).build();
-    Field apiClientField = Client.class.getDeclaredField("apiClient");
-    apiClientField.setAccessible(true);
-    apiClientField.set(client, apiClient);
-
-    // Act
-    client.close();
-
-    // Assert
-    assertTrue(httpClient.dispatcher().executorService().isShutdown());
-    assertEquals(0, httpClient.connectionPool().connectionCount());
-  }
 }

src/test/java/com/google/genai/HttpApiClientTest.java

@@ -23,9 +23,7 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.doNothing;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.*;
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -46,6 +44,7 @@
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+
 import okhttp3.Call;
 import okhttp3.Callback;
 import okhttp3.Dispatcher;
@@ -1483,4 +1482,21 @@ public void testNoDefaultLocationWhenUsingApiKeyOnlyMode(
     assertNull(client.location());
     assertTrue(client.vertexAI());
   }
+
+  @Test
+  public void testCloseClient() {
+    HttpApiClient client =
+            new HttpApiClient(
+                    Optional.empty(),
+                    Optional.of(PROJECT),
+                    Optional.of(LOCATION),
+                    Optional.of(CREDENTIALS),
+                    Optional.empty(),
+                    Optional.empty());
+
+    client.close();
+
+    assertTrue(client.httpClient().dispatcher().executorService().isShutdown());
+    assertEquals(0, client.httpClient().connectionPool().connectionCount());
+  }
 }