diff --git a/appengine/appidentity/src/main/java/com/example/appengine/appidentity/UrlShortener.java b/appengine/appidentity/src/main/java/com/example/appengine/appidentity/UrlShortener.java
new file mode 100644
index 00000000000..cecebe82d6a
--- /dev/null
+++ b/appengine/appidentity/src/main/java/com/example/appengine/appidentity/UrlShortener.java
@@ -0,0 +1,79 @@
+/**
+ * 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
+ *
+ * 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.appengine.appidentity;
+
+import com.google.appengine.api.appidentity.AppIdentityService;
+import com.google.appengine.api.appidentity.AppIdentityServiceFactory;
+import com.google.common.io.CharStreams;
+
+import org.json.JSONObject;
+import org.json.JSONTokener;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+
+@SuppressWarnings("serial")
+class UrlShortener {
+ // [START asserting_identity_to_Google_APIs]
+ /**
+ * Returns a shortened URL by calling the Google URL Shortener API.
+ *
+ * Note: Error handling elided for simplicity.
+ */
+ public String createShortUrl(String longUrl) throws Exception {
+ ArrayList scopes = new ArrayList();
+ scopes.add("https://www.googleapis.com/auth/urlshortener");
+ AppIdentityService appIdentity = AppIdentityServiceFactory.getAppIdentityService();
+ AppIdentityService.GetAccessTokenResult accessToken = appIdentity.getAccessToken(scopes);
+ // The token asserts the identity reported by appIdentity.getServiceAccountName()
+ JSONObject request = new JSONObject();
+ request.put("longUrl", longUrl);
+
+ URL url = new URL("https://www.googleapis.com/urlshortener/v1/url?pp=1");
+ HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+ connection.setDoOutput(true);
+ connection.setRequestMethod("POST");
+ connection.addRequestProperty("Content-Type", "application/json");
+ connection.addRequestProperty("Authorization", "Bearer " + accessToken.getAccessToken());
+
+ OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
+ request.write(writer);
+ writer.close();
+
+ if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
+ // Note: Should check the content-encoding.
+ // Any JSON parser can be used; this one is used for illustrative purposes.
+ JSONTokener response_tokens = new JSONTokener(connection.getInputStream());
+ JSONObject response = new JSONObject(response_tokens);
+ return (String) response.get("id");
+ } else {
+ try (InputStream s = connection.getErrorStream();
+ InputStreamReader r = new InputStreamReader(s, StandardCharsets.UTF_8)) {
+ throw new RuntimeException(String.format(
+ "got error (%d) response %s from %s",
+ connection.getResponseCode(),
+ CharStreams.toString(r),
+ connection.toString()));
+ }
+ }
+ }
+ // [END asserting_identity_to_Google_APIs]
+}
diff --git a/appengine/appidentity/src/main/java/com/example/appengine/appidentity/UrlShortenerServlet.java b/appengine/appidentity/src/main/java/com/example/appengine/appidentity/UrlShortenerServlet.java
new file mode 100644
index 00000000000..8bab40e8115
--- /dev/null
+++ b/appengine/appidentity/src/main/java/com/example/appengine/appidentity/UrlShortenerServlet.java
@@ -0,0 +1,75 @@
+/**
+ * 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
+ *
+ * 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.appengine.appidentity;
+
+import com.google.appengine.api.users.UserService;
+import com.google.appengine.api.users.UserServiceFactory;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.net.URLDecoder;
+
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+@SuppressWarnings("serial")
+public class UrlShortenerServlet extends HttpServlet {
+ private final UrlShortener shortener;
+
+ public UrlShortenerServlet() {
+ shortener = new UrlShortener();
+ }
+
+ @Override
+ public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
+ PrintWriter w = resp.getWriter();
+ w.println("");
+ w.println("");
+ w.println("Asserting Identity to Google APIs - App Engine App Identity Example");
+ w.println("");
+ }
+
+ @Override
+ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
+ resp.setContentType("text/plain");
+ String longUrl = req.getParameter("longUrl");
+ if (longUrl == null) {
+ resp.sendError(HttpServletResponse.SC_BAD_REQUEST, "missing longUrl parameter");
+ return;
+ }
+
+ String shortUrl;
+ PrintWriter w = resp.getWriter();
+ try {
+ shortUrl = shortener.createShortUrl(longUrl);
+ } catch (Exception e) {
+ resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+ w.println("error shortening URL: " + longUrl);
+ e.printStackTrace(w);
+ return;
+ }
+
+ w.print("long URL: ");
+ w.println(longUrl);
+ w.print("short URL: ");
+ w.println(shortUrl);
+ }
+}
diff --git a/appengine/appidentity/src/main/webapp/WEB-INF/web.xml b/appengine/appidentity/src/main/webapp/WEB-INF/web.xml
index 09472a93622..3ebbce0e290 100644
--- a/appengine/appidentity/src/main/webapp/WEB-INF/web.xml
+++ b/appengine/appidentity/src/main/webapp/WEB-INF/web.xml
@@ -7,8 +7,16 @@
appidentity
com.example.appengine.appidentity.IdentityServlet
+
+ urlshortener
+ com.example.appengine.appidentity.UrlShortenerServlet
+
appidentity
/
+
+ urlshortener
+ /shorten
+