Service client sample code class 2

src/main/java/com/google/api/generator/gapic/composer/BUILD.bazel

@@ -15,8 +15,10 @@ java_library(
     deps = [
         "//:service_config_java_proto",
         "//src/main/java/com/google/api/generator/engine/ast",
+        "//src/main/java/com/google/api/generator/engine/writer",
         "//src/main/java/com/google/api/generator/gapic:status_java_proto",
         "//src/main/java/com/google/api/generator/gapic/model",
+        "//src/main/java/com/google/api/generator/gapic/composer/samplecode",
         "//src/main/java/com/google/api/generator/gapic/utils",
         "@com_google_api_api_common//jar",
         "@com_google_api_gax_java//gax",

src/main/java/com/google/api/generator/gapic/composer/ServiceClientClassComposer.java

@@ -119,7 +119,7 @@ public GapicClass generate(Service service, Map<String, Message> messageTypes) {
     ClassDefinition classDef =
         ClassDefinition.builder()
             .setHeaderCommentStatements(
-                ServiceClientCommentComposer.createClassHeaderComments(service))
+                ServiceClientCommentComposer.createClassHeaderComments(service, types))
             .setPackageString(pakkage)
             .setAnnotations(createClassAnnotations(types))
             .setScope(ScopeNode.PUBLIC)

src/main/java/com/google/api/generator/gapic/composer/ServiceClientCommentComposer.java

@@ -17,6 +17,7 @@
 import com.google.api.generator.engine.ast.CommentStatement;
 import com.google.api.generator.engine.ast.JavaDocComment;
 import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.gapic.composer.samplecode.ServiceClientCommentSampleCodeComposer;
 import com.google.api.generator.gapic.model.Method;
 import com.google.api.generator.gapic.model.MethodArgument;
 import com.google.api.generator.gapic.model.Service;
@@ -25,6 +26,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -103,7 +105,8 @@ class ServiceClientCommentComposer {
           "Returns the OperationsClient that can be used to query the status of a long-running"
               + " operation returned by another API method call.");
 
-  static List<CommentStatement> createClassHeaderComments(Service service) {
+  static List<CommentStatement> createClassHeaderComments(
+      Service service, Map<String, TypeNode> types) {
     JavaDocComment.Builder classHeaderJavadocBuilder = JavaDocComment.builder();
     if (service.hasDescription()) {
       classHeaderJavadocBuilder =
@@ -134,9 +137,13 @@ static List<CommentStatement> createClassHeaderComments(Service service) {
             SERVICE_DESCRIPTION_CUSTOMIZE_SUMMARY_PATTERN,
             String.format("%sSettings", JavaStyle.toUpperCamelCase(service.name()))));
     classHeaderJavadocBuilder.addParagraph(SERVICE_DESCRIPTION_CREDENTIALS_SUMMARY_STRING);
-    // TODO(summerji): Add credentials' customization sample code here.
+    classHeaderJavadocBuilder.addSampleCode(
+        ServiceClientCommentSampleCodeComposer.composeClassHeaderCredentialsSampleCode(
+            service, types));
     classHeaderJavadocBuilder.addParagraph(SERVICE_DESCRIPTION_ENDPOINT_SUMMARY_STRING);
-    // TODO(summerji): Add endpoint customization sample code here.
+    classHeaderJavadocBuilder.addSampleCode(
+        ServiceClientCommentSampleCodeComposer.composeClassHeaderEndpointSampleCode(service, types)
+    );
 
     return Arrays.asList(
         CommentComposer.AUTO_GENERATED_CLASS_COMMENT,

src/main/java/com/google/api/generator/gapic/composer/ServiceSettingsClassComposer.java

@@ -54,6 +54,7 @@
 import com.google.api.generator.gapic.model.GapicClass.Kind;
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.Method;
+import com.google.api.generator.gapic.model.Method.Stream;
 import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
@@ -101,7 +102,7 @@ public GapicClass generate(Service service, Map<String, Message> ignore) {
     ClassDefinition classDef =
         ClassDefinition.builder()
             .setPackageString(pakkage)
-            .setHeaderCommentStatements(createClassHeaderComments(service))
+            .setHeaderCommentStatements(createClassHeaderComments(service, types.get(className)))
             .setAnnotations(createClassAnnotations())
             .setScope(ScopeNode.PUBLIC)
             .setName(className)
@@ -119,11 +120,21 @@ public GapicClass generate(Service service, Map<String, Message> ignore) {
     return GapicClass.create(kind, classDef);
   }
 
-  private static List<CommentStatement> createClassHeaderComments(Service service) {
+  private static List<CommentStatement> createClassHeaderComments(
+      Service service, TypeNode classType) {
+    // Pick the first pure unary rpc method, if no such method exist, then pick the first in the
+    // list.
     Optional<Method> methodOpt =
-        service.methods().isEmpty() ? Optional.empty() : Optional.of(service.methods().get(0));
+        service.methods().isEmpty()
+            ? Optional.empty()
+            : Optional.of(
+                service.methods().stream()
+                    .reduce(
+                        (m1, m2) ->
+                            (m1.stream() == Stream.NONE && !m1.hasLro() && !m1.isPaged()) ? m1 : m2)
+                    .get());
     return SettingsCommentComposer.createClassHeaderComments(
-        getClientClassName(service.name()), service.defaultHost(), methodOpt);
+        getClientClassName(service.name()), service.defaultHost(), methodOpt, classType);
   }
 
   private static List<AnnotationNode> createClassAnnotations() {

src/main/java/com/google/api/generator/gapic/composer/ServiceStubSettingsClassComposer.java

@@ -78,6 +78,7 @@
 import com.google.api.generator.gapic.model.GapicServiceConfig;
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.Method;
+import com.google.api.generator.gapic.model.Method.Stream;
 import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
@@ -163,7 +164,7 @@ public GapicClass generate(
     ClassDefinition classDef =
         ClassDefinition.builder()
             .setPackageString(pakkage)
-            .setHeaderCommentStatements(createClassHeaderComments(service))
+            .setHeaderCommentStatements(createClassHeaderComments(service, types.get(className)))
             .setAnnotations(createClassAnnotations())
             .setScope(ScopeNode.PUBLIC)
             .setName(className)
@@ -187,11 +188,21 @@ private static List<AnnotationNode> createClassAnnotations() {
             .build());
   }
 
-  private static List<CommentStatement> createClassHeaderComments(Service service) {
+  private static List<CommentStatement> createClassHeaderComments(
+      Service service, TypeNode classType) {
+    // Pick the first pure unary rpc method, if no such method exist, then pick the first in the
+    // list.
     Optional<Method> methodOpt =
-        service.methods().isEmpty() ? Optional.empty() : Optional.of(service.methods().get(0));
+        service.methods().isEmpty()
+            ? Optional.empty()
+            : Optional.of(
+                service.methods().stream()
+                    .reduce(
+                        (m1, m2) ->
+                            (m1.stream() == Stream.NONE && !m1.hasLro() && !m1.isPaged()) ? m1 : m2)
+                    .get());
     return SettingsCommentComposer.createClassHeaderComments(
-        String.format(STUB_PATTERN, service.name()), service.defaultHost(), methodOpt);
+        String.format(STUB_PATTERN, service.name()), service.defaultHost(), methodOpt, classType);
   }
 
   private static TypeNode createExtendsType(Service service, Map<String, TypeNode> types) {

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

@@ -17,6 +17,8 @@
 import com.google.api.generator.engine.ast.CommentStatement;
 import com.google.api.generator.engine.ast.JavaDocComment;
 import com.google.api.generator.engine.ast.LineComment;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.gapic.composer.samplecode.SettingsCommentSampleCodeComposer;
 import com.google.api.generator.gapic.model.Method;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
@@ -28,6 +30,8 @@
 class SettingsCommentComposer {
   private static final String COLON = ":";
 
+  private static final String CLIENT_CLASS_NAME_PATTERN = "%sClient";
+  private static final String STUB_PATTERN = "%sStub";
   private static final String BUILDER_CLASS_DOC_PATTERN = "Builder for %s.";
   private static final String CALL_SETTINGS_METHOD_DOC_PATTERN =
       "Returns the object with the settings used for calls to %s.";
@@ -102,7 +106,10 @@ static CommentStatement createCallSettingsBuilderGetterComment(String javaMethod
   }
 
   static List<CommentStatement> createClassHeaderComments(
-      String configuredClassName, String defaultHost, Optional<Method> methodOpt) {
+      String configuredClassName,
+      String defaultHost,
+      Optional<Method> methodOpt,
+      TypeNode classType) {
     // Split default address and port.
     int colonIndex = defaultHost.indexOf(COLON);
     Preconditions.checkState(
@@ -127,12 +134,16 @@ static List<CommentStatement> createClassHeaderComments(
             .addParagraph(CLASS_HEADER_BUILDER_DESCRIPTION);
 
     if (methodOpt.isPresent()) {
+      String sampleCode =
+          SettingsCommentSampleCodeComposer.composeSettingClassHeaderSampleCode(
+              methodOpt.get(), classType);
       javaDocCommentBuilder =
-          javaDocCommentBuilder.addParagraph(
-              String.format(
-                  CLASS_HEADER_SAMPLE_CODE_PATTERN,
-                  JavaStyle.toLowerCamelCase(methodOpt.get().name())));
-      // TODO(summerji): Add sample code here.
+          javaDocCommentBuilder
+              .addParagraph(
+                  String.format(
+                      CLASS_HEADER_SAMPLE_CODE_PATTERN,
+                      JavaStyle.toLowerCamelCase(methodOpt.get().name())))
+              .addSampleCode(sampleCode);
     }
 
     return Arrays.asList(

src/main/java/com/google/api/generator/gapic/composer/samplecode/BUILD.bazel

@@ -13,6 +13,11 @@ java_library(
         ":samplecode_files",
     ],
     deps = [
+        "//src/main/java/com/google/api/generator/engine/ast",
+        "//src/main/java/com/google/api/generator/engine/writer",
+        "//src/main/java/com/google/api/generator/gapic/model",
+        "//src/main/java/com/google/api/generator/gapic/utils",
         "@google_java_format_all_deps//jar",
+        "@com_google_api_gax_java//gax",
     ],
 )

src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientCommentSampleCodeComposer.java

@@ -0,0 +1,161 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.samplecode;
+
+import com.google.api.gax.core.FixedCredentialsProvider;
+import com.google.api.generator.engine.ast.AssignmentExpr;
+import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.Expr;
+import com.google.api.generator.engine.ast.ExprStatement;
+import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.Statement;
+import com.google.api.generator.engine.ast.StringObjectValue;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.engine.ast.Variable;
+import com.google.api.generator.engine.ast.VariableExpr;
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.utils.JavaStyle;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.Map;
+
+public class ServiceClientCommentSampleCodeComposer {
+
+  private static final String SETTINGS_NAME_PATTERN = "%sSettings";
+  private static final String CLASS_NAME_PATTERN = "%sClient";
+
+  public static String composeClassHeaderCredentialsSampleCode(Service service, Map<String, TypeNode> types) {
+    String settingsVarName = JavaStyle.toLowerCamelCase(getSettingsName(service.name()));
+    TypeNode settingsVarType = types.get(getSettingsName(service.name()));
+    VariableExpr settingsVarExpr = VariableExpr.withVariable(
+        Variable.builder()
+            .setName(settingsVarName)
+            .setType(settingsVarType)
+            .build());
+    MethodInvocationExpr newBuilderMethodExpr =
+        MethodInvocationExpr.builder()
+        .setStaticReferenceType(settingsVarType)
+        .setMethodName("newBuilder")
+        .build();
+    TypeNode fixedCredentialProvideType = TypeNode.withReference(
+        ConcreteReference.withClazz(FixedCredentialsProvider.class)
+    );
+    MethodInvocationExpr credentialArgExpr =
+        MethodInvocationExpr.builder()
+        .setStaticReferenceType(fixedCredentialProvideType)
+        .setArguments(ValueExpr.withValue(StringObjectValue.withValue("myCredentials")))
+        .setMethodName("create")
+        .build();
+    MethodInvocationExpr credentialsMethodExpr =
+        MethodInvocationExpr.builder()
+        .setExprReferenceExpr(newBuilderMethodExpr)
+        .setArguments(credentialArgExpr)
+        .setMethodName("setCredentialsProvider")
+        .build();
+    MethodInvocationExpr buildMethodExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(credentialsMethodExpr)
+            .setReturnType(settingsVarType)
+            .setMethodName("build")
+            .build();
+
+    Expr initSettingsVarExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(settingsVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(buildMethodExpr)
+            .build();
+
+    String className = JavaStyle.toLowerCamelCase(getClientClassName(service.name()));
+    TypeNode classType = types.get(getClientClassName(service.name()));
+    VariableExpr clientVarExpr = VariableExpr.withVariable(Variable.builder().setName(className).setType(classType).build());
+    MethodInvocationExpr createMethodExpr = MethodInvocationExpr.builder().setStaticReferenceType(classType).setArguments(settingsVarExpr).setMethodName("create").setReturnType(classType).build();
+    Expr initClientVarExpr = AssignmentExpr.builder()
+        .setVariableExpr(clientVarExpr.toBuilder().setIsDecl(true).build())
+        .setValueExpr(createMethodExpr)
+        .build();
+
+    return writeSampleCode(Arrays.asList(initSettingsVarExpr, initClientVarExpr));
+  }
+
+  public static String composeClassHeaderEndpointSampleCode(Service service, Map<String, TypeNode> types) {
+    String settingsVarName = JavaStyle.toLowerCamelCase(getSettingsName(service.name()));
+    TypeNode settingsVarType = types.get(getSettingsName(service.name()));
+    VariableExpr settingsVarExpr = VariableExpr.withVariable(
+        Variable.builder()
+            .setName(settingsVarName)
+            .setType(settingsVarType)
+            .build());
+    MethodInvocationExpr newBuilderMethodExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(settingsVarType)
+            .setMethodName("newBuilder")
+            .build();
+    MethodInvocationExpr credentialsMethodExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(newBuilderMethodExpr)
+            .setArguments(ValueExpr.withValue(StringObjectValue.withValue("myEndpoint")))
+            .setMethodName("setEndpoint")
+            .build();
+    MethodInvocationExpr buildMethodExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(credentialsMethodExpr)
+            .setReturnType(settingsVarType)
+            .setMethodName("build")
+            .build();
+
+    Expr initSettingsVarExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(settingsVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(buildMethodExpr)
+            .build();
+
+    String className = JavaStyle.toLowerCamelCase(getClientClassName(service.name()));
+    TypeNode classType = types.get(getClientClassName(service.name()));
+    VariableExpr clientVarExpr = VariableExpr.withVariable(Variable.builder().setName(className).setType(classType).build());
+    MethodInvocationExpr createMethodExpr = MethodInvocationExpr.builder().setStaticReferenceType(classType).setArguments(settingsVarExpr).setMethodName("create").setReturnType(classType).build();
+    Expr initClientVarExpr = AssignmentExpr.builder()
+        .setVariableExpr(clientVarExpr.toBuilder().setIsDecl(true).build())
+        .setValueExpr(createMethodExpr)
+        .build();
+
+    return writeSampleCode(Arrays.asList(
+        initSettingsVarExpr, initClientVarExpr
+    ));
+  }
+
+  private static String getClientClassName(String serviceName) {
+    return String.format(CLASS_NAME_PATTERN, serviceName);
+  }
+
+  private static String getSettingsName(String serviceName) {
+    return String.format(SETTINGS_NAME_PATTERN, serviceName);
+  }
+
+  private static String writeSampleCode(List<Expr> exprs) {
+    List<Statement> statements =
+        exprs
+            .stream()
+            .map(e -> ExprStatement.withExpr(e))
+            .collect(Collectors.toList());
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    for (Statement statement : statements) {
+      statement.accept(visitor);
+    }
+    return SampleCodeJavaFormatter.format(visitor.write());
+  }
+}