refactor: create a new ExperimentalHostHelper in samples package and update import references

Author: Adarsh-Shrivastava-001

java-spanner/samples/snippets/src/main/java/com/example/spanner/ExperimentalHostHelper.java

@@ -0,0 +1,66 @@
+/*
+ * 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.example.spanner;
+
+import com.google.cloud.spanner.SpannerOptions;
+import com.google.common.base.Strings;
+
+public class ExperimentalHostHelper {
+  private static final String EXPERIMENTAL_HOST = "spanner.experimental_host";
+  private static final String USE_PLAIN_TEXT = "spanner.use_plain_text";
+  private static final String USE_MTLS = "spanner.mtls";
+  private static final String CLIENT_CERT_PATH = "spanner.client_cert_path";
+  private static final String CLIENT_CERT_KEY_PATH = "spanner.client_cert_key_path";
+
+  /**
+   * Checks whether an experimental host is being used. This is done by checking if the
+   * {@code spanner.experimental_host} system property is set.
+   *
+   * @return true if an experimental host is being used. Returns false otherwise.
+   */
+  public static boolean isExperimentalHost() {
+    return !Strings.isNullOrEmpty(System.getProperty(EXPERIMENTAL_HOST));
+  }
+
+  public static boolean isMtlsSetup() {
+    return Boolean.getBoolean(USE_MTLS);
+  }
+
+  public static void setExperimentalHostSpannerOptions(SpannerOptions.Builder builder) {
+    if (!isExperimentalHost()) {
+      throw new IllegalStateException(EXPERIMENTAL_HOST + " must be set to use this method");
+    }
+    String experimentalHost = System.getProperty(EXPERIMENTAL_HOST, "");
+    boolean usePlainText = Boolean.getBoolean(USE_PLAIN_TEXT);
+    builder.setExperimentalHost(experimentalHost);
+    builder.setBuiltInMetricsEnabled(false);
+    if (usePlainText) {
+      builder.usePlainText();
+    }
+    if (isMtlsSetup()) {
+      String clientCertificate = System.getProperty(CLIENT_CERT_PATH, "");
+      String clientKey = System.getProperty(CLIENT_CERT_KEY_PATH, "");
+      if (Strings.isNullOrEmpty(clientCertificate)) {
+        throw new IllegalArgumentException(CLIENT_CERT_PATH + " must be set when mTLS is enabled");
+      }
+      if (Strings.isNullOrEmpty(clientKey)) {
+        throw new IllegalArgumentException(CLIENT_CERT_KEY_PATH + " must be set when mTLS is enabled");
+      }
+      builder.useClientCert(clientCertificate, clientKey);
+    }
+  }
+}

java-spanner/samples/snippets/src/main/java/com/example/spanner/PgSpannerSample.java

@@ -16,8 +16,8 @@
 
 package com.example.spanner;
 
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.isExperimentalHost;
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
+import static com.example.spanner.ExperimentalHostHelper.isExperimentalHost;
+import static com.example.spanner.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
 
 import com.google.api.gax.paging.Page;
 import com.google.cloud.ByteArray;

java-spanner/samples/snippets/src/main/java/com/example/spanner/QueryInformationSchemaDatabaseOptionsSample.java

@@ -18,8 +18,8 @@
 
 // [START spanner_query_information_schema_database_options]
 
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.isExperimentalHost;
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
+import static com.example.spanner.ExperimentalHostHelper.isExperimentalHost;
+import static com.example.spanner.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
 
 import com.google.cloud.spanner.DatabaseClient;
 import com.google.cloud.spanner.DatabaseId;

java-spanner/samples/snippets/src/main/java/com/example/spanner/SpannerGraphSample.java

@@ -16,8 +16,8 @@
 
 package com.example.spanner;
 
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.isExperimentalHost;
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
+import static com.example.spanner.ExperimentalHostHelper.isExperimentalHost;
+import static com.example.spanner.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
 
 import com.google.cloud.Timestamp;
 import com.google.cloud.spanner.DatabaseClient;

java-spanner/samples/snippets/src/main/java/com/example/spanner/SpannerSample.java

@@ -16,8 +16,8 @@
 
 package com.example.spanner;
 
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.isExperimentalHost;
-import static com.google.cloud.spanner.testing.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
+import static com.example.spanner.ExperimentalHostHelper.isExperimentalHost;
+import static com.example.spanner.ExperimentalHostHelper.setExperimentalHostSpannerOptions;
 
 import static com.google.cloud.spanner.Type.StructField;