URL not found when running sample code

Question

I'm trying to run a sample that I took from Google to see if I could access Google+ from App Engine. I added the following files to my project and set up the servlet mapping so that they are available on the paths they are expected to be at. I deployed it to app engine and tried accessing the application. Going to https://mydomain.appspot.com/ gives me Error: NOT_FOUND. Accessing the urls of the servlets gives me the exceptions mentioned below. Samples are taken from https://github.com/google/google-api-java-client-samples/tree/master/plus-appengine-sample

These samples might not be up to date, but they are the newest I can find from Google. Any clue to what I should do to get this working would be helpful.

My classes look like this:

BasicServlet:

public class PlusBasicServlet extends HttpServlet {

    /**
     * Enter your API key here from https://code.google.com/apis/console/?api=plus under "API Access".
     */
    private static final String API_KEY = "AIzaSyB9NEc2yQRisoj-rIqgg35yeZXReASMRCI";

    private static final long serialVersionUID = 1;

    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        HttpTransport httpTransport = new UrlFetchTransport();
        JsonFactory jsonFactory = new JacksonFactory();

        Plus plus = new Plus.Builder(httpTransport, jsonFactory, null).setApplicationName("")
                .setGoogleClientRequestInitializer(new PlusRequestInitializer(API_KEY)).build();

        ActivityFeed myActivityFeed = plus.activities().search("Google").execute();
        List<Activity> myActivities = myActivityFeed.getItems();

        resp.setContentType("text/html");
        resp.setStatus(200);
        Writer writer = resp.getWriter();
        writer.write("<ul>");
        for (Activity a : myActivities) {
            writer.write("<li>" + a.getTitle() + "</li>");
        }
        writer.write("</ul>");
    }

}

Util:

class Utils {

    /**
     * Global instance of the {@link DataStoreFactory}. The best practice is to make it a single
     * globally shared instance across your application.
     */
    private static final AppEngineDataStoreFactory DATA_STORE_FACTORY =
            AppEngineDataStoreFactory.getDefaultInstance();

    private static GoogleClientSecrets clientSecrets = null;
    private static final Set<String> SCOPES = Collections.singleton(PlusScopes.PLUS_ME);
    static final String MAIN_SERVLET_PATH = "/plussampleservlet";
    static final String AUTH_CALLBACK_SERVLET_PATH = "/oauth2callback";
    static final UrlFetchTransport HTTP_TRANSPORT = new UrlFetchTransport();
    static final JacksonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();

    private static GoogleClientSecrets getClientSecrets() throws IOException {
        if (clientSecrets == null) {
            clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,
                    new InputStreamReader(Utils.class.getResourceAsStream("/plus_secret.json")));
            Preconditions.checkArgument(!clientSecrets.getDetails().getClientId().startsWith("Enter ")
                            && !clientSecrets.getDetails().getClientSecret().startsWith("Enter "),
                    "Download client_secrets.json file from https://code.google.com/apis/console/?api=plus "
                            + "into plus-appengine-sample/src/main/resources/client_secrets.json");
        }
        return clientSecrets;
    }

    static GoogleAuthorizationCodeFlow initializeFlow() throws IOException {
        return new GoogleAuthorizationCodeFlow.Builder(
                HTTP_TRANSPORT, JSON_FACTORY, getClientSecrets(), SCOPES).setDataStoreFactory(
                DATA_STORE_FACTORY).setAccessType("offline").build();
    }

    static String getRedirectUri(HttpServletRequest req) {
        GenericUrl requestUrl = new GenericUrl(req.getRequestURL().toString());
        requestUrl.setRawPath(AUTH_CALLBACK_SERVLET_PATH);
        return requestUrl.build();
    }
}

Exception when accessing basic servlet:

Uncaught exception from servlet
com.google.api.client.googleapis.json.GoogleJsonResponseException: 403
{
  "code" : 403,
  "errors" : [ {
    "domain" : "usageLimits",
    "message" : "The request did not specify any referer. Please ensure that the client is sending referer or use the API Console to remove the referer restrictions.",
    "reason" : "ipRefererBlocked",
    "extendedHelp" : "https://console.developers.google.com/apis/credentials?project=602263912930"
  } ],
  "message" : "The request did not specify any referer. Please ensure that the client is sending referer or use the API Console to remove the referer restrictions."
}
    at com.google.api.client.googleapis.json.GoogleJsonResponseException.from(GoogleJsonResponseException.java:146)
    at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:113)
    at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:40)
    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest$1.interceptResponse(AbstractGoogleClientRequest.java:321)

Answer 1

{
  "code" : 403,
  "errors" : [ {
    "domain" : "usageLimits",
    "message" : "The request did not specify any referer. Please ensure that the client is sending referer or use the API Console to remove the referer restrictions.",
    "reason" : "ipRefererBlocked",
    "extendedHelp" : "https://console.developers.google.com/apis/credentials?project=602263912930"
  } ],
  "message" : "The request did not specify any referer. Please ensure that the client is sending referer or use the API Console to remove the referer restrictions."
}

When you created your api key on Google Developer console you added an IP restriction or domain restriction. Your requests are coming from some place other then the restriction you have supplied. Either remove the restriction or add the correct i formation.

Note the code form the actual documentation pages should be reasonably up to date. Activites.search scroll down to examples.