[Cloud Tasks] Add HTTP push queue sample

appengine-java8/tasks/README.md

@@ -69,12 +69,15 @@ location is "us-central1").
 export LOCATION_ID=<YOUR_ZONE>
 ```
 
+### Using App Engine Queues
 Create a task, targeted at the `/tasks/create` endpoint, with a payload specified:
 
 ```
 mvn exec:java -Dexec.mainClass="com.example.task.CreateTask" \
     -Dexec.args="--project-id $GOOGLE_CLOUD_PROJECT \
-    --queue $QUEUE_ID --location $LOCATION_ID --payload hello"
+    --queue $QUEUE_ID \
+    --location $LOCATION_ID \
+    --payload hello"
 ```
 
 The App Engine app serves as a target for the push requests. It has an
@@ -89,3 +92,18 @@ mvn exec:java -Dexec.mainClass="com.example.task.CreateTask" \
     -Dexec.args="--project-id $GOOGLE_CLOUD_PROJECT \
     --queue $QUEUE_ID --location $LOCATION_ID --payload hello --in-seconds 30"
 ```
+
+### Using HTTP Push Queues
+
+Set an environment variable for the endpoint to your task handler. This is an
+example url to send requests to the App Engine task handler:
+```
+export URL=https://${PROJECT_ID}.appspot.com/tasks/create
+```
+
+Running the sample will create a task and send the task to the specific URL
+endpoint, with a payload specified:
+
+```
+mvn exec:java -Dexec.mainClass="com.example.task.CreateHttpTask"
+```

appengine-java8/tasks/pom.xml

@@ -88,7 +88,6 @@ Copyright 2018 Google LLC
         <artifactId>exec-maven-plugin</artifactId>
         <version>1.6.0</version>
         <configuration>
-          <mainClass>com.example.task.CreateTask</mainClass>
           <cleanupDaemonThreads>false</cleanupDaemonThreads>
         </configuration>
       </plugin>

appengine-java8/tasks/src/main/java/com/example/task/CreateHttpTask.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2018 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.task;
+
+import com.google.cloud.tasks.v2beta3.CloudTasksClient;
+import com.google.cloud.tasks.v2beta3.HttpMethod;
+import com.google.cloud.tasks.v2beta3.HttpRequest;
+import com.google.cloud.tasks.v2beta3.QueueName;
+import com.google.cloud.tasks.v2beta3.Task;
+import com.google.common.base.Strings;
+import com.google.protobuf.ByteString;
+import com.google.protobuf.Timestamp;
+
+import java.nio.charset.Charset;
+import java.time.Clock;
+import java.time.Instant;
+
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.CommandLineParser;
+import org.apache.commons.cli.DefaultParser;
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.Option;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.ParseException;
+
+public class CreateHttpTask {
+
+  public static void main(String[] args) throws Exception {
+    String projectId = System.getenv("PROJECT_ID");
+    String queueName = System.getenv("QUEUE_ID");
+    String location = System.getenv("LOCATION_ID");
+    String url = System.getenv("URL");
+
+    // [START cloud_tasks_create_http_task]
+    // Instantiates a client.
+    try (CloudTasksClient client = CloudTasksClient.create()) {
+
+      // Variables provided by the CLI.
+      // projectId = "my-project-id";
+      // queueName = "my-appengine-queue";
+      // location = "us-central1";
+      // url = "https://<project-id>.appspot.com/tasks/create";
+      String payload = "hello";
+
+      // Construct the fully qualified queue name.
+      String queuePath = QueueName.of(projectId, location, queueName).toString();
+
+      // Construct the task body.
+      Task.Builder taskBuilder = Task
+          .newBuilder()
+          .setHttpRequest(HttpRequest.newBuilder()
+              .setBody(ByteString.copyFrom(payload, Charset.defaultCharset()))
+              .setUrl(url)
+              .setHttpMethod(HttpMethod.POST)
+              .build());
+
+      // Send create task request.
+      Task task = client.createTask(queuePath, taskBuilder.build());
+      System.out.println("Task created: " + task.getName());
+    }
+    // [END cloud_tasks_create_http_task]
+  }
+}

appengine-java8/tasks/src/main/java/com/example/task/CreateTask.java

@@ -161,8 +161,8 @@ private static void printUsage(Options options) {
     HelpFormatter formatter = new HelpFormatter();
     formatter.printHelp(
         "client",
-        "A simple Cloud Tasks command line client that triggers a call to an AppEngine "
-            + "endpoint.",
+        "A simple Cloud Tasks command line client that creates a task with an "
+            + "App Engine endpoint.",
         options, "", true);
     throw new RuntimeException();
   }

appengine-java8/tasks/src/main/java/com/example/task/TaskServlet.java

@@ -38,7 +38,7 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
     String body = req.getReader()
         .lines()
         .reduce("", (accumulator, actual) -> accumulator + actual);
-        
+
     if (!body.isEmpty()) {
       log.info("Request payload: " + body);
       String output = String.format("Received task with payload %s", body);