Add service version info

.changes/next-release/feature-AWSSDKforJavav2-382b343.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "AWS SDK for Java v2",
+    "contributor": "",
+    "description": "Adding constant to each SDK module to represent its version"
+}

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/tasks/CommonInternalGeneratorTasks.java

@@ -22,6 +22,7 @@
 import software.amazon.awssdk.codegen.emitters.PoetGeneratorTask;
 import software.amazon.awssdk.codegen.poet.client.EnvironmentTokenSystemSettingsClass;
 import software.amazon.awssdk.codegen.poet.client.SdkClientOptions;
+import software.amazon.awssdk.codegen.poet.client.specs.ServiceVersionInfoSpec;
 import software.amazon.awssdk.codegen.poet.common.UserAgentUtilsSpec;
 
 public class CommonInternalGeneratorTasks extends BaseGeneratorTasks {
@@ -40,6 +41,7 @@ protected List<GeneratorTask> createTasks() throws Exception {
         if (params.getModel().getCustomizationConfig().isEnableEnvironmentBearerToken()) {
             tasks.add(createEnvironmentTokenSystemSettingTask());
         }
+        tasks.add(createServiceVersionInfoTask());
         return tasks;
     }
 
@@ -58,6 +60,11 @@ private GeneratorTask createEnvironmentTokenSystemSettingTask() {
                                      new EnvironmentTokenSystemSettingsClass(params.getModel()));
     }
 
+    private GeneratorTask createServiceVersionInfoTask() {
+        return new PoetGeneratorTask(clientOptionsDir(), params.getModel().getFileHeader(),
+                                     new ServiceVersionInfoSpec(params.getModel()));
+    }
+
     private String clientOptionsDir() {
         return params.getPathProvider().getClientInternalDirectory();
     }

codegen/src/main/java/software/amazon/awssdk/codegen/poet/PoetExtension.java

@@ -79,6 +79,10 @@ public ClassName getUserAgentClass() {
         return ClassName.get(model.getMetadata().getFullClientInternalPackageName(), "UserAgentUtils");
     }
 
+    public ClassName getServiceVersionInfoClass() {
+        return ClassName.get(model.getMetadata().getFullClientInternalPackageName(), "ServiceVersionInfo");
+    }
+
     public ClassName getEnvironmentTokenSystemSettingsClass() {
         return ClassName.get(model.getMetadata().getFullClientInternalPackageName(), "EnvironmentTokenSystemSettings");
     }

codegen/src/main/java/software/amazon/awssdk/codegen/poet/client/specs/ServiceVersionInfoSpec.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.poet.client.specs;
+
+import static software.amazon.awssdk.core.util.VersionInfo.SDK_VERSION;
+
+import com.squareup.javapoet.ClassName;
+import com.squareup.javapoet.FieldSpec;
+import com.squareup.javapoet.MethodSpec;
+import com.squareup.javapoet.TypeSpec;
+import javax.lang.model.element.Modifier;
+import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
+import software.amazon.awssdk.codegen.poet.ClassSpec;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
+import software.amazon.awssdk.codegen.poet.PoetUtils;
+
+public class ServiceVersionInfoSpec implements ClassSpec {
+    private final PoetExtension poetExtension;
+
+    public ServiceVersionInfoSpec(IntermediateModel model) {
+        this.poetExtension = new PoetExtension(model);
+    }
+
+    @Override
+    public TypeSpec poetSpec() {
+        TypeSpec.Builder builder = TypeSpec.classBuilder("ServiceVersionInfo")
+                                           .addModifiers(Modifier.PUBLIC, Modifier.FINAL)
+                                           .addAnnotation(PoetUtils.generatedAnnotation())
+                                           .addField(FieldSpec.builder(
+                                               String.class, "VERSION", Modifier.PUBLIC, Modifier.STATIC, Modifier.FINAL)
+                                                              .initializer("$S", SDK_VERSION)
+                                                              .addJavadoc("Returns the current version for the AWS SDK in which"
+                                                                          + " this class is running.")
+                                                              .build())
+                                           .addMethod(privateConstructor());
+
+        return builder.build();
+    }
+
+    protected MethodSpec privateConstructor() {
+        return MethodSpec.constructorBuilder()
+                         .addModifiers(Modifier.PRIVATE)
+                         .build();
+    }
+
+    @Override
+    public ClassName className() {
+        return poetExtension.getServiceVersionInfoClass();
+    }
+}

codegen/src/test/java/software/amazon/awssdk/codegen/poet/client/ServiceVersionInfoSpecTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.poet.client;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+import static org.hamcrest.Matchers.equalToIgnoringWhiteSpace;
+
+import com.squareup.javapoet.JavaFile;
+import com.squareup.javapoet.TypeSpec;
+import java.io.InputStream;
+import java.util.Scanner;
+import org.junit.jupiter.api.Test;
+import software.amazon.awssdk.codegen.poet.ClassSpec;
+import software.amazon.awssdk.codegen.poet.ClientTestModels;
+import software.amazon.awssdk.codegen.poet.client.specs.ServiceVersionInfoSpec;
+import software.amazon.awssdk.core.util.VersionInfo;
+
+public class ServiceVersionInfoSpecTest {
+
+    // Fixture test that compares generated ServiceVersionInfo class against expected output.
+    // The fixture file uses {{VERSION}} as a placeholder which gets replaced with the current
+    // SDK version at test time, since the generated code injects the actual version at build time.
+    @Test
+    void testServiceVersionInfoClass() {
+        String currVersion = VersionInfo.SDK_VERSION;
+        ClassSpec serviceVersionInfoSpec = new ServiceVersionInfoSpec(ClientTestModels.restJsonServiceModels());
+
+        String expectedContent = loadFixtureFile("test-service-version-info-class.java");
+        expectedContent = expectedContent.replace("{{VERSION}}", currVersion);
+
+        String actualContent = generateContent(serviceVersionInfoSpec);
+
+        assertThat(actualContent).isEqualToIgnoringWhitespace(expectedContent);
+    }
+
+    private String loadFixtureFile(String filename) {
+        InputStream is = getClass().getResourceAsStream("specs/" + filename);
+        return new Scanner(is).useDelimiter("\\A").next();
+    }
+
+    private String generateContent(ClassSpec spec) {
+        TypeSpec typeSpec = spec.poetSpec();
+        JavaFile javaFile = JavaFile.builder(spec.className().packageName(), typeSpec).build();
+        return javaFile.toString();
+    }
+}

codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/specs/test-service-version-info-class.java

@@ -0,0 +1,15 @@
+package software.amazon.awssdk.services.json.internal;
+
+import java.lang.String;
+import software.amazon.awssdk.annotations.Generated;
+
+@Generated("software.amazon.awssdk:codegen")
+public final class ServiceVersionInfo {
+  /**
+   * Returns the current version for the AWS SDK in which this class is running.
+   */
+  public static final String VERSION = "{{VERSION}}";
+
+  private ServiceVersionInfo() {
+  }
+}