HTTP ERROR 500 Проблема с доступом / _ah / API / Explorer

Question

Я пытаюсь создать приложение для Android с API конечной точки, но я новичок в Google App Engine.

Насколько я понимаю, в SDK включен какой-то API Explorer, который должен позволить мне протестировать /проверьте мой API - в документах говорится: «Протестируйте бэкэнд API в Google API Explorer, перейдя к http://localhost:8888/_ah/api/explorer". Но я не могу найти документацию о том, что API Explorer на самом деле является, делает или выглядит.

В моем случае, когда я нажимаю http://localhost:8888/_ah/api/explorer Я получаю ошибку 500

HTTP ERROR 500
Problem accessing /_ah/api/explorer. Reason:

    com.google.api.server.spi.Strings.stripSlash(Ljava/lang/String;)Ljava/lang/String;
Caused by:
java.lang.NoSuchMethodError: com.google.api.server.spi.Strings.stripSlash(Ljava/lang/String;)Ljava/lang/String;
    at com.google.api.server.spi.EndpointsServlet.service(EndpointsServlet.java:68)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:72)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:134)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:48)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerRequestLogFilter.doFilter(DevAppServerRequestLogFilter.java:44)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:95)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:508)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

Я не понимаю ошибку :(

это мой код AsyncTaskи я использую Java 8

class EndpointsAsyncTask extends AsyncTask<Pair<Context, String>, Void, String> {
    private static MyApi myApiService = null;
    private Context context;
        @Override
        protected String doInBackground(Pair<Context, String>... params) {
            if(myApiService == null) {  // Only do this once
                MyApi.Builder builder = new MyApi.Builder(AndroidHttp.newCompatibleTransport(),
                        new AndroidJsonFactory(), null)
                        // options for running against local devappserver
                        // - 10.0.2.2 is localhost's IP address in Android emulator
                        // - turn off compression when running against local devappserver
                        .setRootUrl("http://10.0.2.2:8888/_ah/api/")
                        .setGoogleClientRequestInitializer(new GoogleClientRequestInitializer() {
                            @Override
                            public void initialize(AbstractGoogleClientRequest<?> abstractGoogleClientRequest) throws IOException {
                                abstractGoogleClientRequest.setDisableGZipContent(true);
                            }
                        });
                // end options for devappserver

                myApiService = builder.build();
            }

            context = params[0].first;
            String name = params[0].second;

            try {
                 return myApiService.sayHi(name).execute().getData();
            } catch (IOException e) {
                return e.getMessage();
            }
        }

        @Override
        protected void onPostExecute(String result) {
            Toast.makeText(context, result, Toast.LENGTH_LONG).show();
        }
    }

, и это мой код конечной точки

@Api(
        name = "myApi",
        version = "v1",
        namespace = @ApiNamespace(
                ownerDomain = "backend.builditbigger.gradle.udacity.com",
                ownerName = "backend.builditbigger.gradle.udacity.com",
                packagePath=""
        )
)
public class MyEndpoint {

    /** A simple endpoint method that takes a name and says Hi back */
    @ApiMethod(name = "sayHi")
    public MyBean sayHi(@Named("name") String name) {
        MyBean response = new MyBean();
        response.setData("Hi, " + name);

        return response;
    }
}