docs(sample): relocate native image sample from old repo

README.md

@@ -56,13 +56,13 @@ implementation 'com.google.cloud:google-cloud-spanner'
 If you are using Gradle without BOM, add this to your dependencies
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-spanner:6.25.4'
+implementation 'com.google.cloud:google-cloud-spanner:6.25.5'
 ```
 
 If you are using SBT, add this to your dependencies
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.25.4"
+libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.25.5"
 ```
 
 ## Authentication
@@ -240,6 +240,9 @@ Samples are in the [`samples/`](https://github.com/googleapis/java-spanner/tree/
 
 | Sample                      | Source Code                       | Try it |
 | --------------------------- | --------------------------------- | ------ |
+| Database Operations | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/native-image/src/main/java/com/example/spanner/DatabaseOperations.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/native-image/src/main/java/com/example/spanner/DatabaseOperations.java) |
+| Instance Operations | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/native-image/src/main/java/com/example/spanner/InstanceOperations.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/native-image/src/main/java/com/example/spanner/InstanceOperations.java) |
+| Native Image Spanner Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/native-image/src/main/java/com/example/spanner/NativeImageSpannerSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/native-image/src/main/java/com/example/spanner/NativeImageSpannerSample.java) |
 | Add Json Column Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/AddJsonColumnSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/AddJsonColumnSample.java) |
 | Add Numeric Column Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/AddNumericColumnSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/AddNumericColumnSample.java) |
 | Async Dml Example | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/AsyncDmlExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/AsyncDmlExample.java) |

samples/native-image/README.md

@@ -0,0 +1,92 @@
+# Spanner Sample Application with Native Image
+
+This is a sample application which uses the Cloud Spanner client libraries and demonstrates compatibility with Native Image compilation.
+
+The application creates a new Spanner instance and database, and it runs basic operations including queries and Spanner mutations.
+
+## Setup Instructions
+
+You will need to follow these prerequisite steps in order to run these samples:
+
+1. If you have not already, [create a Google Cloud Platform Project](https://cloud.google.com/resource-manager/docs/creating-managing-projects#creating_a_project).
+
+2. Install the [Google Cloud SDK](https://cloud.google.com/sdk/) which will allow you to run the sample with your project's credentials.
+
+   Once installed, log in with Application Default Credentials using the following command:
+
+    ```
+    gcloud auth application-default login
+    ```
+
+   **Note:** Authenticating with Application Default Credentials is convenient to use during development, but we recommend [alternate methods of authentication](https://cloud.google.com/docs/authentication/production) during production use.
+
+3. Install the GraalVM compiler.
+
+   You can follow the [official installation instructions](https://www.graalvm.org/docs/getting-started-with-graalvm/#install-graalvm) from the GraalVM website.
+   After following the instructions, ensure that you install the Native Image extension installed by running:
+
+    ```
+    gu install native-image
+    ```
+
+   Once you finish following the instructions, verify that the default version of Java is set to the GraalVM version by running `java -version` in a terminal.
+
+   You will see something similar to the below output:
+
+    ```
+    $ java -version
+
+   openjdk version "11.0.15" 2022-04-19
+   OpenJDK Runtime Environment GraalVM CE 22.1.0 (build 11.0.15+10-jvmci-22.1-b06)
+   OpenJDK 64-Bit Server VM GraalVM CE 22.1.0 (build 11.0.15+10-jvmci-22.1-b06, mixed mode, sharing)
+
+    ```
+## Run with Native Image Compilation
+
+1. **(Optional)** If you wish to run the application against the [Spanner emulator](https://cloud.google.com/spanner/docs/emulator), make sure that you have the [Google Cloud SDK](https://cloud.google.com/sdk) installed.
+
+   In a new terminal window, start the emulator via `gcloud`:
+
+    ```
+    gcloud beta emulators spanner start
+    ```
+
+   You may leave the emulator running for now.
+   In the next section, we will run the sample application against the Spanner emulator instsance.
+
+2. Navigate to this directory and compile the application with the Native Image compiler.
+
+    ```
+    mvn package -P native -DskipTests
+    ```
+
+3. **(Optional)** If you're using the emulator, export the `SPANNER_EMULATOR_HOST` as an environment variable in your terminal.
+
+    ```
+    export SPANNER_EMULATOR_HOST=localhost:9010
+    ``` 
+
+   The Spanner Client Libraries will detect this environment variable and will automatically connect to the emulator instance if this variable is set.
+
+4. Run the application.
+
+    ```
+    ./target/native-image
+    ```
+
+5. The application will run through some basic Spanner operations and log some output statements.
+
+    ```
+    Running the Spanner Sample.
+    Singers Registered in Spanner:
+    Bob Loblaw
+    Virginia Watson
+    ```
+
+## Sample Integration test with Native Image Support
+
+In order to run the sample integration test as a native image, call the following command:
+
+   ```
+   mvn test -Pnative
+   ```

samples/native-image/pom.xml

@@ -0,0 +1,164 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.google.cloud</groupId>
+  <artifactId>native-image</artifactId>
+  <name>Native Image Sample</name>
+  <url>https://github.com/googleapis/java-spanner</url>
+
+  <!--
+    The parent pom defines common style checks and testing strategies for our samples.
+    Removing or replacing it should not affect the execution of the samples in anyway.
+  -->
+  <parent>
+    <groupId>com.google.cloud.samples</groupId>
+    <artifactId>shared-configuration</artifactId>
+    <version>1.2.0</version>
+  </parent>
+
+  <properties>
+    <!-- Java 8 because the Kokoro Sample test uses that Java version -->
+    <maven.compiler.target>1.8</maven.compiler.target>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>com.google.cloud</groupId>
+        <artifactId>libraries-bom</artifactId>
+        <version>25.2.0</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.google.cloud</groupId>
+      <artifactId>google-cloud-spanner</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.13.2</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.google.truth</groupId>
+      <artifactId>truth</artifactId>
+      <version>1.1.3</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <!-- This plugin enables building the application to a JAR *not* using Native Image -->
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
+        <version>3.2.2</version>
+        <configuration>
+          <archive>
+            <manifest>
+              <addClasspath>true</addClasspath>
+              <classpathPrefix>dependency-jars/</classpathPrefix>
+              <mainClass>com.example.spanner.NativeImageSpannerSample</mainClass>
+            </manifest>
+          </archive>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-dependency-plugin</artifactId>
+        <version>3.3.0</version>
+        <executions>
+          <execution>
+            <id>copy-dependencies</id>
+            <phase>package</phase>
+            <goals>
+              <goal>copy-dependencies</goal>
+            </goals>
+            <configuration>
+              <outputDirectory>
+                ${project.build.directory}/dependency-jars/
+              </outputDirectory>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+
+  <!-- Native Profile-->
+  <profiles>
+    <profile>
+      <id>native</id>
+
+      <dependencies>
+        <dependency>
+          <groupId>org.junit.vintage</groupId>
+          <artifactId>junit-vintage-engine</artifactId>
+          <version>5.8.2</version>
+          <scope>test</scope>
+        </dependency>
+        <dependency>
+          <groupId>org.graalvm.buildtools</groupId>
+          <artifactId>junit-platform-native</artifactId>
+          <version>0.9.10</version>
+          <scope>test</scope>
+        </dependency>
+      </dependencies>
+
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-surefire-plugin
+            </artifactId> <!-- Must use older version of surefire plugin for native-image testing. -->
+            <version>2.22.2</version>
+            <configuration>
+              <includes>
+                <include>**/*IT</include>
+              </includes>
+            </configuration>
+          </plugin>
+          <plugin>
+            <groupId>org.graalvm.buildtools</groupId>
+            <artifactId>native-maven-plugin</artifactId>
+            <version>0.9.9</version>
+            <extensions>true</extensions>
+            <configuration>
+              <mainClass>com.example.spanner.NativeImageSpannerSample</mainClass>
+              <buildArgs>
+                <buildArg>--no-fallback</buildArg>
+                <buildArg>--no-server</buildArg>
+              </buildArgs>
+            </configuration>
+            <executions>
+              <execution>
+                <id>build-native</id>
+                <goals>
+                  <goal>build</goal>
+                  <goal>test</goal>
+                </goals>
+                <phase>package</phase>
+              </execution>
+              <execution>
+                <id>test-native</id>
+                <goals>
+                  <goal>test</goal>
+                </goals>
+                <phase>test</phase>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
+</project>

samples/native-image/src/main/java/com/example/spanner/DatabaseOperations.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2022 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.example.spanner;
+
+import com.google.cloud.spanner.Database;
+import com.google.cloud.spanner.DatabaseAdminClient;
+import com.google.cloud.spanner.DatabaseClient;
+import com.google.cloud.spanner.KeySet;
+import com.google.cloud.spanner.Mutation;
+import com.google.cloud.spanner.ResultSet;
+import com.google.cloud.spanner.Statement;
+import com.google.common.collect.ImmutableList;
+import java.util.Collections;
+import java.util.List;
+
+/** Helper methods to manage Spanner Databases. */
+public class DatabaseOperations {
+
+  private static final List<String> DDL_STATEMENTS =
+      ImmutableList.of(
+          "CREATE TABLE Singers (SingerId INT64 NOT NULL, FirstName "
+              + "STRING(1024), LastName STRING(1024)) PRIMARY KEY (SingerId)");
+
+  static void createDatabase(
+      DatabaseAdminClient databaseAdminClient, String instanceId, String databaseId) {
+
+    if (databaseExists(databaseAdminClient, instanceId, databaseId)) {
+      databaseAdminClient.dropDatabase(instanceId, databaseId);
+    }
+    databaseAdminClient.createDatabase(instanceId, databaseId, DDL_STATEMENTS);
+  }
+
+  static boolean databaseExists(
+      DatabaseAdminClient databaseAdminClient, String instanceId, String databaseId) {
+
+    for (Database database : databaseAdminClient.listDatabases(instanceId).iterateAll()) {
+      if (databaseId.equals(database.getId().getDatabase())) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  static void insertUsingDml(DatabaseClient dbClient) {
+    dbClient
+        .readWriteTransaction()
+        .run(
+            transaction -> {
+              String sql =
+                  "INSERT INTO Singers (SingerId, FirstName, LastName) "
+                      + " VALUES (10, 'Virginia', 'Watson')";
+              transaction.executeUpdate(Statement.of(sql));
+              return null;
+            });
+  }
+
+  static void insertUsingMutation(DatabaseClient dbClient) {
+    Mutation mutation =
+        Mutation.newInsertBuilder("Singers")
+            .set("SingerId")
+            .to(12)
+            .set("FirstName")
+            .to("Bob")
+            .set("LastName")
+            .to("Loblaw")
+            .build();
+    dbClient.write(Collections.singletonList(mutation));
+  }
+
+  static ResultSet performRead(DatabaseClient dbClient) {
+    return dbClient.singleUse().executeQuery(Statement.of("SELECT * FROM Singers"));
+  }
+
+  static void deleteDatabase(DatabaseClient dbClient) {
+    dbClient.write(Collections.singletonList(Mutation.delete("Singers", KeySet.all())));
+    System.out.println("Records deleted.");
+  }
+}