feat: Client/StubSettings' getEndpoint() returns the resolved endpoint (#2440)

## Changes
- Client|StubSettings `getEndpoint()` will now return the fully resolved
endpoint
- Client|StubSettings `getUniverseDomain()` will not return the fully
resolved universe domain
- Remove the generated `getEndpoint()` method in the
{Client}StubSettings class. The call to `getEndpoint()` will now always
hit the parent StubSettings and return the fully resolved endpoint.

---------

Co-authored-by: Blake Li <[email protected]>

Author: lqiu96

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/comment/SettingsCommentComposer.java

@@ -52,9 +52,6 @@ public class SettingsCommentComposer {
   private static final String CLASS_HEADER_DEFAULTS_RETRIES_DESCRIPTION =
       "Retries are configured for idempotent methods but not for non-idempotent methods.";
 
-  public static final CommentStatement GET_ENDPOINT_COMMENT =
-      toSimpleComment(
-          "Returns the endpoint set by the user or the the service's default endpoint.");
   public static final CommentStatement DEFAULT_SCOPES_COMMENT =
       toSimpleComment("The default scopes of the service.");
 

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java

@@ -999,7 +999,6 @@ private List<MethodDefinition> createClassMethods(
     javaMethods.addAll(
         createMethodSettingsGetterMethods(methodSettingsMemberVarExprs, deprecatedSettingVarNames));
     javaMethods.add(createCreateStubMethod(service, typeStore));
-    javaMethods.add(createGetEndpointMethod());
     javaMethods.addAll(createDefaultHelperAndGetterMethods(service, typeStore));
     javaMethods.addAll(
         createNewBuilderMethods(
@@ -1013,45 +1012,6 @@ private List<MethodDefinition> createClassMethods(
     return javaMethods;
   }
 
-  // Helper method to create the getEndpoint method in the ServiceStubSettings class
-  private MethodDefinition createGetEndpointMethod() {
-    Expr getEndpointExpr =
-        MethodInvocationExpr.builder()
-            .setMethodName("getEndpoint")
-            .setExprReferenceExpr(
-                ValueExpr.withValue(
-                    SuperObjectValue.withType(
-                        TypeNode.withReference(ConcreteReference.withClazz(StubSettings.class)))))
-            .setReturnType(TypeNode.STRING)
-            .build();
-    Expr isNotNullCheck =
-        RelationalOperationExpr.notEqualToWithExprs(getEndpointExpr, ValueExpr.createNullExpr());
-
-    IfStatement ifStatement =
-        IfStatement.builder()
-            .setConditionExpr(isNotNullCheck)
-            .setBody(ImmutableList.of(ExprStatement.withExpr(ReturnExpr.withExpr(getEndpointExpr))))
-            .build();
-
-    Expr getDefaultEndpointExpr =
-        MethodInvocationExpr.builder()
-            .setMethodName("getDefaultEndpoint")
-            .setReturnType(TypeNode.STRING)
-            .build();
-    ReturnExpr returnExpr = ReturnExpr.withExpr(getDefaultEndpointExpr);
-
-    return MethodDefinition.builder()
-        .setHeaderCommentStatements(SettingsCommentComposer.GET_ENDPOINT_COMMENT)
-        .setScope(ScopeNode.PUBLIC)
-        .setIsStatic(false)
-        .setAnnotations(ImmutableList.of(AnnotationNode.OVERRIDE))
-        .setReturnType(TypeNode.STRING)
-        .setName("getEndpoint")
-        .setBody(ImmutableList.of(ifStatement))
-        .setReturnExpr(returnExpr)
-        .build();
-  }
-
   private static List<MethodDefinition> createMethodSettingsGetterMethods(
       Map<String, VariableExpr> methodSettingsMemberVarExprs,
       final Set<String> deprecatedSettingVarNames) {
@@ -1497,7 +1457,6 @@ private List<MethodDefinition> createNestedClassMethods(
     nestedClassMethods.addAll(
         createNestedClassSettingsBuilderGetterMethods(
             nestedMethodSettingsMemberVarExprs, nestedDeprecatedSettingVarNames));
-    nestedClassMethods.add(createGetEndpointMethod());
     nestedClassMethods.add(createNestedClassBuildMethod(service, typeStore));
     return nestedClassMethods;
   }

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStubSettings.golden

@@ -101,15 +101,6 @@ public class DeprecatedServiceStubSettings extends StubSettings<DeprecatedServic
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns a builder for the default ExecutorProvider for this service. */
   public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
     return InstantiatingExecutorProvider.newBuilder();
@@ -292,15 +283,6 @@ public class DeprecatedServiceStubSettings extends StubSettings<DeprecatedServic
       return slowFibonacciSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public DeprecatedServiceStubSettings build() throws IOException {
       return new DeprecatedServiceStubSettings(this);

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStubSettings.golden

@@ -285,15 +285,6 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns a builder for the default ExecutorProvider for this service. */
   public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
     return InstantiatingExecutorProvider.newBuilder();
@@ -635,15 +626,6 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       return collideNameSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public EchoStubSettings build() throws IOException {
       return new EchoStubSettings(this);

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingServiceV2StubSettings.golden

@@ -421,15 +421,6 @@ public class LoggingServiceV2StubSettings extends StubSettings<LoggingServiceV2S
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns the default service name. */
   @Override
   public String getServiceName() {
@@ -738,15 +729,6 @@ public class LoggingServiceV2StubSettings extends StubSettings<LoggingServiceV2S
       return tailLogEntriesSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public LoggingServiceV2StubSettings build() throws IOException {
       return new LoggingServiceV2StubSettings(this);

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/PublisherStubSettings.golden

@@ -430,15 +430,6 @@ public class PublisherStubSettings extends StubSettings<PublisherStubSettings> {
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns the default service name. */
   @Override
   public String getServiceName() {
@@ -810,15 +801,6 @@ public class PublisherStubSettings extends StubSettings<PublisherStubSettings> {
       return detachSubscriptionSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public PublisherStubSettings build() throws IOException {
       return new PublisherStubSettings(this);

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpcrest/goldens/EchoStubSettings.golden

@@ -301,15 +301,6 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns a builder for the default ExecutorProvider for this service. */
   public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
     return InstantiatingExecutorProvider.newBuilder();
@@ -694,15 +685,6 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       return updateCaseSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public EchoStubSettings build() throws IOException {
       return new EchoStubSettings(this);

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpcrest/goldens/WickedStubSettings.golden

@@ -99,15 +99,6 @@ public class WickedStubSettings extends StubSettings<WickedStubSettings> {
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns a builder for the default ExecutorProvider for this service. */
   public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
     return InstantiatingExecutorProvider.newBuilder();
@@ -284,15 +275,6 @@ public class WickedStubSettings extends StubSettings<WickedStubSettings> {
       return persuadeEvilPlanSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public WickedStubSettings build() throws IOException {
       return new WickedStubSettings(this);

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceStubSettings.golden

@@ -131,15 +131,6 @@ public class ComplianceStubSettings extends StubSettings<ComplianceStubSettings>
             "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
   }
 
-  /** Returns the endpoint set by the user or the the service's default endpoint. */
-  @Override
-  public String getEndpoint() {
-    if (super.getEndpoint() != null) {
-      return super.getEndpoint();
-    }
-    return getDefaultEndpoint();
-  }
-
   /** Returns a builder for the default ExecutorProvider for this service. */
   public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
     return InstantiatingExecutorProvider.newBuilder();
@@ -417,15 +408,6 @@ public class ComplianceStubSettings extends StubSettings<ComplianceStubSettings>
       return verifyEnumSettings;
     }
 
-    /** Returns the endpoint set by the user or the the service's default endpoint. */
-    @Override
-    public String getEndpoint() {
-      if (super.getEndpoint() != null) {
-        return super.getEndpoint();
-      }
-      return getDefaultEndpoint();
-    }
-
     @Override
     public ComplianceStubSettings build() throws IOException {
       return new ComplianceStubSettings(this);

gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallContext.java

@@ -140,7 +140,7 @@ private GrpcCallContext(
       ApiCallContextOptions options,
       @Nullable RetrySettings retrySettings,
       @Nullable Set<StatusCode.Code> retryableCodes,
-      EndpointContext endpointContext) {
+      @Nullable EndpointContext endpointContext) {
     this.channel = channel;
     this.credentials = credentials;
     this.callOptions = Preconditions.checkNotNull(callOptions);
@@ -152,7 +152,14 @@ private GrpcCallContext(
     this.options = Preconditions.checkNotNull(options);
     this.retrySettings = retrySettings;
     this.retryableCodes = retryableCodes == null ? null : ImmutableSet.copyOf(retryableCodes);
-    this.endpointContext = endpointContext;
+    // Attempt to create an empty, non-functioning EndpointContext by default. The client will have
+    // a valid EndpointContext with user configurations after the client has been initialized.
+    try {
+      this.endpointContext =
+          endpointContext == null ? EndpointContext.newBuilder().build() : endpointContext;
+    } catch (IOException ex) {
+      throw new RuntimeException(ex);
+    }
   }
 
   /**