feat: Enable REST transport for most of Java and Go clients (#262)

- [ ] Regenerate this pull request now.

PiperOrigin-RevId: 456641589

Source-Link: googleapis/googleapis@8a251f5

Source-Link: https://github.com/googleapis/googleapis-gen/commit/4ca52a529cf01308d9714950edffbea3560cfbdb
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiNGNhNTJhNTI5Y2YwMTMwOGQ5NzE0OTUwZWRmZmJlYTM1NjBjZmJkYiJ9

java-api-gateway/google-cloud-api-gateway/pom.xml

@@ -58,6 +58,10 @@
       <groupId>com.google.api</groupId>
       <artifactId>gax-grpc</artifactId>
     </dependency>
+    <dependency>
+      <groupId>com.google.api</groupId>
+      <artifactId>gax-httpjson</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.threeten</groupId>
       <artifactId>threetenbp</artifactId>
@@ -77,12 +81,24 @@
       <scope>test</scope>
     </dependency>
     <!-- Need testing utility classes for generated gRPC clients tests -->
+    <dependency>
+      <groupId>com.google.api</groupId>
+      <artifactId>gax</artifactId>
+      <classifier>testlib</classifier>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>com.google.api</groupId>
       <artifactId>gax-grpc</artifactId>
       <classifier>testlib</classifier>
       <scope>test</scope>
     </dependency>
+    <dependency>
+    <groupId>com.google.api</groupId>
+      <artifactId>gax-httpjson</artifactId>
+      <classifier>testlib</classifier>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <profiles>

java-api-gateway/google-cloud-api-gateway/src/main/java/com/google/cloud/apigateway/v1/ApiGatewayServiceClient.java

@@ -19,6 +19,7 @@
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.httpjson.longrunning.OperationsClient;
 import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.AbstractFixedSizeCollection;
 import com.google.api.gax.paging.AbstractPage;
@@ -30,7 +31,6 @@
 import com.google.cloud.apigateway.v1.stub.ApiGatewayServiceStubSettings;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.longrunning.Operation;
-import com.google.longrunning.OperationsClient;
 import com.google.protobuf.Empty;
 import com.google.protobuf.FieldMask;
 import java.io.IOException;
@@ -105,13 +105,29 @@
  *     ApiGatewayServiceClient.create(apiGatewayServiceSettings);
  * }</pre>
  *
+ * <p>To use REST (HTTP1.1/JSON) transport (instead of gRPC) for sending and receiving requests over
+ * the wire:
+ *
+ * <pre>{@code
+ * // This snippet has been automatically generated for illustrative purposes only.
+ * // It may require modifications to work in your environment.
+ * ApiGatewayServiceSettings apiGatewayServiceSettings =
+ *     ApiGatewayServiceSettings.newBuilder()
+ *         .setTransportChannelProvider(
+ *             ApiGatewayServiceSettings.defaultHttpJsonTransportProviderBuilder().build())
+ *         .build();
+ * ApiGatewayServiceClient apiGatewayServiceClient =
+ *     ApiGatewayServiceClient.create(apiGatewayServiceSettings);
+ * }</pre>
+ *
  * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
  */
 @Generated("by gapic-generator-java")
 public class ApiGatewayServiceClient implements BackgroundResource {
   private final ApiGatewayServiceSettings settings;
   private final ApiGatewayServiceStub stub;
-  private final OperationsClient operationsClient;
+  private final OperationsClient httpJsonOperationsClient;
+  private final com.google.longrunning.OperationsClient operationsClient;
 
   /** Constructs an instance of ApiGatewayServiceClient with default settings. */
   public static final ApiGatewayServiceClient create() throws IOException {
@@ -143,13 +159,17 @@ public static final ApiGatewayServiceClient create(ApiGatewayServiceStub stub) {
   protected ApiGatewayServiceClient(ApiGatewayServiceSettings settings) throws IOException {
     this.settings = settings;
     this.stub = ((ApiGatewayServiceStubSettings) settings.getStubSettings()).createStub();
-    this.operationsClient = OperationsClient.create(this.stub.getOperationsStub());
+    this.operationsClient =
+        com.google.longrunning.OperationsClient.create(this.stub.getOperationsStub());
+    this.httpJsonOperationsClient = OperationsClient.create(this.stub.getHttpJsonOperationsStub());
   }
 
   protected ApiGatewayServiceClient(ApiGatewayServiceStub stub) {
     this.settings = null;
     this.stub = stub;
-    this.operationsClient = OperationsClient.create(this.stub.getOperationsStub());
+    this.operationsClient =
+        com.google.longrunning.OperationsClient.create(this.stub.getOperationsStub());
+    this.httpJsonOperationsClient = OperationsClient.create(this.stub.getHttpJsonOperationsStub());
   }
 
   public final ApiGatewayServiceSettings getSettings() {
@@ -164,10 +184,18 @@ public ApiGatewayServiceStub getStub() {
    * Returns the OperationsClient that can be used to query the status of a long-running operation
    * returned by another API method call.
    */
-  public final OperationsClient getOperationsClient() {
+  public final com.google.longrunning.OperationsClient getOperationsClient() {
     return operationsClient;
   }
 
+  /**
+   * Returns the OperationsClient that can be used to query the status of a long-running operation
+   * returned by another API method call.
+   */
+  public final OperationsClient getHttpJsonOperationsClient() {
+    return httpJsonOperationsClient;
+  }
+
   // AUTO-GENERATED DOCUMENTATION AND METHOD.
   /**
    * Lists Gateways in a given project and location.

java-api-gateway/google-cloud-api-gateway/src/main/java/com/google/cloud/apigateway/v1/ApiGatewayServiceSettings.java

@@ -25,6 +25,7 @@
 import com.google.api.gax.core.GoogleCredentialsProvider;
 import com.google.api.gax.core.InstantiatingExecutorProvider;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.ClientSettings;
@@ -234,11 +235,18 @@ public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilde
     return ApiGatewayServiceStubSettings.defaultCredentialsProviderBuilder();
   }
 
-  /** Returns a builder for the default ChannelProvider for this service. */
+  /** Returns a builder for the default gRPC ChannelProvider for this service. */
   public static InstantiatingGrpcChannelProvider.Builder defaultGrpcTransportProviderBuilder() {
     return ApiGatewayServiceStubSettings.defaultGrpcTransportProviderBuilder();
   }
 
+  /** Returns a builder for the default REST ChannelProvider for this service. */
+  @BetaApi
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return ApiGatewayServiceStubSettings.defaultHttpJsonTransportProviderBuilder();
+  }
+
   public static TransportChannelProvider defaultTransportChannelProvider() {
     return ApiGatewayServiceStubSettings.defaultTransportChannelProvider();
   }
@@ -248,11 +256,17 @@ public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuil
     return ApiGatewayServiceStubSettings.defaultApiClientHeaderProviderBuilder();
   }
 
-  /** Returns a new builder for this class. */
+  /** Returns a new gRPC builder for this class. */
   public static Builder newBuilder() {
     return Builder.createDefault();
   }
 
+  /** Returns a new REST builder for this class. */
+  @BetaApi
+  public static Builder newHttpJsonBuilder() {
+    return Builder.createHttpJsonDefault();
+  }
+
   /** Returns a new builder for this class. */
   public static Builder newBuilder(ClientContext clientContext) {
     return new Builder(clientContext);
@@ -290,6 +304,11 @@ private static Builder createDefault() {
       return new Builder(ApiGatewayServiceStubSettings.newBuilder());
     }
 
+    @BetaApi
+    private static Builder createHttpJsonDefault() {
+      return new Builder(ApiGatewayServiceStubSettings.newHttpJsonBuilder());
+    }
+
     public ApiGatewayServiceStubSettings.Builder getStubSettingsBuilder() {
       return ((ApiGatewayServiceStubSettings.Builder) getStubSettings());
     }

java-api-gateway/google-cloud-api-gateway/src/main/java/com/google/cloud/apigateway/v1/stub/ApiGatewayServiceStub.java

@@ -60,7 +60,11 @@
 public abstract class ApiGatewayServiceStub implements BackgroundResource {
 
   public OperationsStub getOperationsStub() {
-    throw new UnsupportedOperationException("Not implemented: getOperationsStub()");
+    return null;
+  }
+
+  public com.google.api.gax.httpjson.longrunning.stub.OperationsStub getHttpJsonOperationsStub() {
+    return null;
   }
 
   public UnaryCallable<ListGatewaysRequest, ListGatewaysPagedResponse> listGatewaysPagedCallable() {

java-api-gateway/google-cloud-api-gateway/src/main/java/com/google/cloud/apigateway/v1/stub/ApiGatewayServiceStubSettings.java

@@ -30,6 +30,9 @@
 import com.google.api.gax.grpc.GrpcTransportChannel;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.api.gax.grpc.ProtoOperationTransformers;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
 import com.google.api.gax.longrunning.OperationSnapshot;
 import com.google.api.gax.longrunning.OperationTimedPollAlgorithm;
 import com.google.api.gax.retrying.RetrySettings;
@@ -457,6 +460,11 @@ public ApiGatewayServiceStub createStub() throws IOException {
         .equals(GrpcTransportChannel.getGrpcTransportName())) {
       return GrpcApiGatewayServiceStub.create(this);
     }
+    if (getTransportChannelProvider()
+        .getTransportName()
+        .equals(HttpJsonTransportChannel.getHttpJsonTransportName())) {
+      return HttpJsonApiGatewayServiceStub.create(this);
+    }
     throw new UnsupportedOperationException(
         String.format(
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
@@ -489,30 +497,56 @@ public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilde
         .setUseJwtAccessWithScope(true);
   }
 
-  /** Returns a builder for the default ChannelProvider for this service. */
+  /** Returns a builder for the default gRPC ChannelProvider for this service. */
   public static InstantiatingGrpcChannelProvider.Builder defaultGrpcTransportProviderBuilder() {
     return InstantiatingGrpcChannelProvider.newBuilder()
         .setMaxInboundMessageSize(Integer.MAX_VALUE);
   }
 
+  /** Returns a builder for the default REST ChannelProvider for this service. */
+  @BetaApi
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return InstantiatingHttpJsonChannelProvider.newBuilder();
+  }
+
   public static TransportChannelProvider defaultTransportChannelProvider() {
     return defaultGrpcTransportProviderBuilder().build();
   }
 
   @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
-  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+  public static ApiClientHeaderProvider.Builder defaultGrpcApiClientHeaderProviderBuilder() {
     return ApiClientHeaderProvider.newBuilder()
         .setGeneratedLibToken(
             "gapic", GaxProperties.getLibraryVersion(ApiGatewayServiceStubSettings.class))
         .setTransportToken(
             GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion());
   }
 
-  /** Returns a new builder for this class. */
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultHttpJsonApiClientHeaderProviderBuilder() {
+    return ApiClientHeaderProvider.newBuilder()
+        .setGeneratedLibToken(
+            "gapic", GaxProperties.getLibraryVersion(ApiGatewayServiceStubSettings.class))
+        .setTransportToken(
+            GaxHttpJsonProperties.getHttpJsonTokenName(),
+            GaxHttpJsonProperties.getHttpJsonVersion());
+  }
+
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return ApiGatewayServiceStubSettings.defaultGrpcApiClientHeaderProviderBuilder();
+  }
+
+  /** Returns a new gRPC builder for this class. */
   public static Builder newBuilder() {
     return Builder.createDefault();
   }
 
+  /** Returns a new REST builder for this class. */
+  public static Builder newHttpJsonBuilder() {
+    return Builder.createHttpJsonDefault();
+  }
+
   /** Returns a new builder for this class. */
   public static Builder newBuilder(ClientContext clientContext) {
     return new Builder(clientContext);
@@ -747,6 +781,19 @@ private static Builder createDefault() {
       return initDefaults(builder);
     }
 
+    private static Builder createHttpJsonDefault() {
+      Builder builder = new Builder(((ClientContext) null));
+
+      builder.setTransportChannelProvider(defaultHttpJsonTransportProviderBuilder().build());
+      builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
+      builder.setInternalHeaderProvider(defaultHttpJsonApiClientHeaderProviderBuilder().build());
+      builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
+
+      return initDefaults(builder);
+    }
+
     private static Builder initDefaults(Builder builder) {
       builder
           .listGatewaysSettings()