diff --git a/appengine/guestbook-cloud-datastore/README.md b/appengine/guestbook-cloud-datastore/README.md
new file mode 100644
index 00000000000..1c6d6957c8a
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/README.md
@@ -0,0 +1,28 @@
+# appengine/guestbook-cloud-datastore
+
+An App Engine guestbook using Java, Maven, and the Cloud Datastore API via
+[google-cloud-java](https://github.com/GoogleCloudPlatform/google-cloud-java).
+
+Please ask questions on [StackOverflow](http://stackoverflow.com/questions/tagged/google-app-engine).
+
+## Running Locally
+
+First, pick a project ID. You can create a project in the [Cloud Console] if you'd like, though this
+isn't necessary unless you'd like to deploy the sample.
+
+Second, modify `Persistence.java`: replace `your-project-id-here` with the project ID you picked.
+
+Then start the [Cloud Datastore Emulator](https://cloud.google.com/datastore/docs/tools/datastore-emulator):
+
+ gcloud beta emulators datastore start --project=YOUR_PROJECT_ID_HERE
+
+Finally, in a new shell, [set the Datastore Emulator environmental variables](https://cloud.google.com/datastore/docs/tools/datastore-emulator#setting_environment_variables)
+and run
+
+ mvn clean appengine:run
+
+## Deploying
+
+Modify `appengine-web.xml` to reflect your app ID and version, then:
+
+ mvn clean appengine:deploy
diff --git a/appengine/guestbook-cloud-datastore/pom.xml b/appengine/guestbook-cloud-datastore/pom.xml
new file mode 100644
index 00000000000..bc7683efe06
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/pom.xml
@@ -0,0 +1,101 @@
+
+
+
+ 4.0.0
+ war
+ 1.0-SNAPSHOT
+
+ com.example.appengine
+ appengine-guestbook-cloud-datastore
+
+ 19.0
+
+
+ com.google.cloud
+ doc-samples
+ 1.0.0
+ ../..
+
+
+
+
+ 3.3.9
+
+
+
+
+
+
+ com.google.appengine
+ appengine-api-1.0-sdk
+ ${appengine.sdk.version}
+
+
+ javax.servlet
+ servlet-api
+ 2.5
+ provided
+
+
+ jstl
+ jstl
+ 1.2
+
+
+
+ com.google.cloud
+ google-cloud
+ 0.4.0
+
+
+
+ com.google.guava
+ guava
+ ${guava.version}
+
+
+
+
+ junit
+ junit
+ 4.12
+ test
+
+
+ org.mockito
+ mockito-all
+ 1.10.19
+ test
+
+
+ com.google.appengine
+ appengine-testing
+ ${appengine.sdk.version}
+ test
+
+
+ com.google.appengine
+ appengine-api-stubs
+ ${appengine.sdk.version}
+ test
+
+
+ com.google.appengine
+ appengine-tools-sdk
+ ${appengine.sdk.version}
+ test
+
+
+
+
+
+
+ com.google.cloud.tools
+ appengine-maven-plugin
+ 1.0.0
+
+
+
+
diff --git a/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Greeting.java b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Greeting.java
new file mode 100644
index 00000000000..12eb3d6c6de
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Greeting.java
@@ -0,0 +1,123 @@
+/**
+ * Copyright 2016 Google Inc. 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. You may obtain a copy of the License at
+ *
+ *
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.
+ */
+
+//[START all]
+package com.example.guestbook;
+
+import static com.example.guestbook.Persistence.getDatastore;
+
+import com.google.cloud.datastore.DateTime;
+import com.google.cloud.datastore.Entity;
+import com.google.cloud.datastore.FullEntity;
+import com.google.cloud.datastore.FullEntity.Builder;
+import com.google.cloud.datastore.IncompleteKey;
+import com.google.cloud.datastore.Key;
+import com.google.common.base.MoreObjects;
+
+import java.util.Date;
+import java.util.Objects;
+
+public class Greeting {
+ private Guestbook book;
+
+ public Key key;
+ public String authorEmail;
+ public String authorId;
+ public String content;
+ public Date date;
+
+ public Greeting() {
+ date = new Date();
+ }
+
+ public Greeting(String book, String content) {
+ this();
+ this.book = new Guestbook(book);
+ this.content = content;
+ }
+
+ public Greeting(String book, String content, String id, String email) {
+ this(book, content);
+ authorEmail = email;
+ authorId = id;
+ }
+
+ public Greeting(Entity entity) {
+ key = entity.hasKey() ? entity.key() : null;
+ authorEmail = entity.contains("authorEmail") ? entity.getString("authorEmail") : null;
+ authorId = entity.contains("authorId") ? entity.getString("authorId") : null;
+ date = entity.contains("date") ? entity.getDateTime("date").toDate() : null;
+ content = entity.contains("content") ? entity.getString("content") : null;
+ }
+
+ public void save() {
+ if (key == null) {
+ key = getDatastore().allocateId(makeIncompleteKey()); // Give this greeting a unique ID
+ }
+
+ Builder builder = FullEntity.builder(key);
+
+ if (authorEmail != null) {
+ builder.set("authorEmail", authorEmail);
+ }
+
+ if (authorId != null) {
+ builder.set("authorId", authorId);
+ }
+
+ builder.set("content", content);
+ builder.set("date", DateTime.copyFrom(date));
+
+ getDatastore().put(builder.build());
+ }
+
+ private IncompleteKey makeIncompleteKey() {
+ // The book is our ancestor key.
+ return Key.builder(book.getKey(), "Greeting").build();
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) {
+ return true;
+ }
+ if (o == null || getClass() != o.getClass()) {
+ return false;
+ }
+ Greeting greeting = (Greeting) o;
+ return Objects.equals(key, greeting.key)
+ && Objects.equals(authorEmail, greeting.authorEmail)
+ && Objects.equals(authorId, greeting.authorId)
+ && Objects.equals(content, greeting.content)
+ && Objects.equals(date, greeting.date);
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(key, authorEmail, authorId, content, date);
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(this)
+ .add("key", key)
+ .add("authorEmail", authorEmail)
+ .add("authorId", authorId)
+ .add("content", content)
+ .add("date", date)
+ .add("book", book)
+ .toString();
+ }
+}
+//[END all]
diff --git a/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Guestbook.java b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Guestbook.java
new file mode 100644
index 00000000000..ae407175ecb
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Guestbook.java
@@ -0,0 +1,98 @@
+/**
+ * Copyright 2016 Google Inc. 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. You may obtain a copy of the License at
+ *
+ *
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.guestbook;
+
+import static com.example.guestbook.Persistence.getDatastore;
+import static com.example.guestbook.Persistence.getKeyFactory;
+import static com.google.cloud.datastore.StructuredQuery.OrderBy.desc;
+import static com.google.cloud.datastore.StructuredQuery.PropertyFilter.hasAncestor;
+
+import com.google.cloud.datastore.Entity;
+import com.google.cloud.datastore.EntityQuery;
+import com.google.cloud.datastore.Key;
+import com.google.cloud.datastore.KeyFactory;
+import com.google.cloud.datastore.Query;
+import com.google.cloud.datastore.QueryResults;
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableList.Builder;
+
+import java.util.List;
+import java.util.Objects;
+
+//[START all]
+public class Guestbook {
+ private static final KeyFactory keyFactory = getKeyFactory(Guestbook.class);
+ private final Key key;
+
+ public final String book;
+
+ public Guestbook(String book) {
+ this.book = book == null ? "default" : book;
+ key =
+ keyFactory.newKey(
+ this.book); // There is a 1:1 mapping between Guestbook names and Guestbook objects
+ }
+
+ public Key getKey() {
+ return key;
+ }
+
+ public List getGreetings() {
+ // This query requires the index defined in index.yaml to work because of the orderBy on date.
+ EntityQuery query =
+ Query.entityQueryBuilder()
+ .kind("Greeting")
+ .filter(hasAncestor(key))
+ .orderBy(desc("date"))
+ .limit(5)
+ .build();
+
+ QueryResults results = getDatastore().run(query);
+
+ Builder resultListBuilder = ImmutableList.builder();
+ while (results.hasNext()) {
+ resultListBuilder.add(new Greeting(results.next()));
+ }
+
+ return resultListBuilder.build();
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) {
+ return true;
+ }
+ if (o == null || getClass() != o.getClass()) {
+ return false;
+ }
+ Guestbook guestbook = (Guestbook) o;
+ return Objects.equals(book, guestbook.book) && Objects.equals(key, guestbook.key);
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(book, key);
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(this)
+ .add("keyFactory", keyFactory)
+ .add("book", book)
+ .add("key", key)
+ .toString();
+ }
+}
+//[END all]
diff --git a/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Persistence.java b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Persistence.java
new file mode 100644
index 00000000000..3dbc2285743
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/Persistence.java
@@ -0,0 +1,42 @@
+/**
+ * Copyright 2016 Google Inc. 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. You may obtain a copy of the License at
+ *
+ *
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.guestbook;
+
+import com.google.cloud.datastore.Datastore;
+import com.google.cloud.datastore.DatastoreOptions;
+import com.google.cloud.datastore.KeyFactory;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+//[START all]
+public class Persistence {
+ private static AtomicReference datastore = new AtomicReference<>();
+
+ public static Datastore getDatastore() {
+ if (datastore.get() == null) {
+ datastore.set(DatastoreOptions.builder().projectId("your-project-id-here").build().service());
+ }
+
+ return datastore.get();
+ }
+
+ public static void setDatastore(Datastore datastore) {
+ Persistence.datastore.set(datastore);
+ }
+
+ public static KeyFactory getKeyFactory(Class c) {
+ return getDatastore().newKeyFactory().kind(c.getSimpleName());
+ }
+}
+//[END all]
diff --git a/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/SignGuestbookServlet.java b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/SignGuestbookServlet.java
new file mode 100644
index 00000000000..8d6061a7146
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/main/java/com/example/guestbook/SignGuestbookServlet.java
@@ -0,0 +1,50 @@
+/**
+ * Copyright 2016 Google Inc. 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. You may obtain a copy of the License at
+ *
+ *
Hello, ${fn:escapeXml(user.nickname)}! (You can
+ sign out.)
+<%
+ } else {
+%>
+
Hello!
+ Sign in
+ to include your name with greetings you post.
+<%
+ }
+%>
+
+<%-- //[START datastore]--%>
+<%
+ // Create the correct Ancestor key
+ Guestbook theBook = new Guestbook(guestbookName);
+
+ // Run an ancestor query to ensure we see the most up-to-date
+ // view of the Greetings belonging to the selected Guestbook.
+ List greetings = theBook.getGreetings();
+
+ if (greetings.isEmpty()) {
+%>
+
Guestbook '${fn:escapeXml(guestbookName)}' has no messages.
+<%
+ } else {
+%>
+
Messages in Guestbook '${fn:escapeXml(guestbookName)}'.
+<%
+ }
+ }
+%>
+
+
+<%-- //[END datastore]--%>
+
+
+
+
+<%-- //[END all]--%>
diff --git a/appengine/guestbook-cloud-datastore/src/main/webapp/stylesheets/main.css b/appengine/guestbook-cloud-datastore/src/main/webapp/stylesheets/main.css
new file mode 100644
index 00000000000..05d72d5536d
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/main/webapp/stylesheets/main.css
@@ -0,0 +1,4 @@
+body {
+ font-family: Verdana, Helvetica, sans-serif;
+ background-color: #FFFFCC;
+}
diff --git a/appengine/guestbook-cloud-datastore/src/test/java/com/example/guestbook/GreetingTest.java b/appengine/guestbook-cloud-datastore/src/test/java/com/example/guestbook/GreetingTest.java
new file mode 100644
index 00000000000..6ddaa732d37
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/test/java/com/example/guestbook/GreetingTest.java
@@ -0,0 +1,50 @@
+/**
+ * Copyright 2016 Google Inc. 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. You may obtain a copy of the License at
+ *
+ *
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.guestbook;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.util.List;
+
+@RunWith(JUnit4.class)
+public class GreetingTest {
+
+ @Before
+ public void setUp() {
+ TestUtils.startDatastore();
+ }
+
+ @Test
+ public void testSaveGreeting() throws Exception {
+ Greeting greeting = new Greeting(null, "Test!");
+ greeting.save();
+
+ Guestbook guestbook = new Guestbook(null);
+ List greetings = guestbook.getGreetings();
+ assertTrue(greetings.size() == 1);
+ assertEquals(greeting, greetings.get(0));
+ }
+
+ @After
+ public void tearDown() {
+ TestUtils.stopDatastore();
+ }
+}
diff --git a/appengine/guestbook-cloud-datastore/src/test/java/com/example/guestbook/SignGuestbookServletTest.java b/appengine/guestbook-cloud-datastore/src/test/java/com/example/guestbook/SignGuestbookServletTest.java
new file mode 100644
index 00000000000..243fca2a858
--- /dev/null
+++ b/appengine/guestbook-cloud-datastore/src/test/java/com/example/guestbook/SignGuestbookServletTest.java
@@ -0,0 +1,70 @@
+/**
+ * Copyright 2016 Google Inc. 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. You may obtain a copy of the License at
+ *
+ *