samples(testing): add retry rule

samples/snippets/src/test/java/pubsub/Retry.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2021 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 pubsub;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Retry {}

samples/snippets/src/test/java/pubsub/RetryRule.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2021 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 pubsub;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+public class RetryRule implements TestRule {
+
+  private AtomicInteger count;
+
+  public RetryRule(int count){
+    super();
+    this.count = new AtomicInteger(count);
+  }
+
+  @Override
+  public Statement apply(final Statement statement, final Description description) {
+    return new Statement() {
+      @Override
+      public void evaluate() throws Throwable {
+        while (count.getAndDecrement() > 0) {
+          try {
+            statement.evaluate();
+            return;
+          } catch (Throwable throwable) {
+            if (count.get() > 0 && description.getAnnotation(Retry.class)!= null) {
+              System.out.println(description.getDisplayName() + "failed.");
+              System.out.println(count.toString() + " retries remain.");
+            } else {
+              throw throwable;
+            }
+          }
+        }
+      }
+    };
+  }
+}

samples/snippets/src/test/java/pubsub/SchemaIT.java

@@ -73,7 +73,9 @@ private static void requireEnvVar(String varName) {
         System.getenv(varName));
   }
 
-  @Rule public Timeout globalTimeout = Timeout.seconds(300); // 5 minute timeout
+  @Rule public Timeout globalTimeout = Timeout.seconds(600); // 10 minute timeout
+
+  @Rule public RetryRule retryRule = new RetryRule(3); // Retry 3 times.
 
   @BeforeClass
   public static void checkRequirements() {
@@ -116,6 +118,7 @@ public void tearDown() throws Exception {
   }
 
   @Test
+  @Retry
   public void testSchema() throws Exception {
     // Test creating Avro schema.
     CreateAvroSchemaExample.createAvroSchemaExample(projectId, avroSchemaId, absoluteAvscFilePath);