Java tutorial
/* * Copyright 2012 The Android Open Source Project * * 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.richmond.riddler; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; import org.json.JSONException; import org.json.JSONObject; import android.os.AsyncTask; import android.util.Log; import com.google.android.gms.auth.GoogleAuthUtil; /** * Display personalized greeting. This class contains boilerplate code to consume the token but * isn't integral to getting the tokens. */ public abstract class AbstractGetNameTask extends AsyncTask<Void, Void, Void> { public static String getmName() { return mName; } public static void setmName(String mName) { AbstractGetNameTask.mName = mName; } private static final String TAG = "TokenInfoTask"; private static final String NAME_KEY = "given_name"; protected LogonActivity mActivity; private boolean mIsAuthenticated = false; protected String mScope; protected String mEmail; protected int mRequestCode; private static String mName = ""; private static String mEmailAddress; public static void setmEmailAddress(String mEmailAddress) { AbstractGetNameTask.mEmailAddress = mEmailAddress; } public static String getmEmailAddress() { return mEmailAddress; } public static String getName() { return mName; } public void setAuth(boolean isAuth) { mIsAuthenticated = isAuth; } AbstractGetNameTask(LogonActivity activity, String email, String scope, int requestCode) { this.mActivity = activity; this.mScope = scope; this.mEmail = email; this.mRequestCode = requestCode; setmEmailAddress(mEmail); } @Override protected Void doInBackground(Void... params) { try { fetchNameFromProfileServer(); } catch (IOException ex) { onError("Following Error occured, please try again. " + ex.getMessage(), ex); } catch (JSONException e) { onError("Bad response: " + e.getMessage(), e); } return null; } @Override protected void onPostExecute(Void result) { // TODO Auto-generated method stub super.onPostExecute(result); if (mIsAuthenticated) mActivity.Login(); } protected void onError(String msg, Exception e) { if (e != null) { Log.e(TAG, "Exception: ", e); } mActivity.show(msg); // will be run in UI thread } /** * Get a authentication token if one is not available. If the error is not recoverable then * it displays the error message on parent activity. */ protected abstract String fetchToken() throws IOException; /** * Contacts the user info server to get the profile of the user and extracts the first name * of the user from the profile. In order to authenticate with the user info server the method * first fetches an access token from Google Play services. * @throws IOException if communication with user info server failed. * @throws JSONException if the response from the server could not be parsed. */ private void fetchNameFromProfileServer() throws IOException, JSONException { String token = fetchToken(); if (token == null) { // error has already been handled in fetchToken() return; } URL url = new URL("https://www.googleapis.com/oauth2/v1/userinfo?access_token=" + token); HttpURLConnection con = (HttpURLConnection) url.openConnection(); int sc = con.getResponseCode(); if (sc == 200) { InputStream is = con.getInputStream(); mName = getFirstName(readResponse(is)); //mActivity.setName(name); mActivity.show("Hello " + mName + "!"); setAuth(true); is.close(); return; } else if (sc == 401) { GoogleAuthUtil.invalidateToken(mActivity, token); onError("Server auth error, please try again.", null); Log.i(TAG, "Server auth error: " + readResponse(con.getErrorStream())); return; } else { onError("Server returned the following error code: " + sc, null); return; } } /** * Reads the response from the input stream and returns it as a string. */ private static String readResponse(InputStream is) throws IOException { ByteArrayOutputStream bos = new ByteArrayOutputStream(); byte[] data = new byte[2048]; int len = 0; while ((len = is.read(data, 0, data.length)) >= 0) { bos.write(data, 0, len); } return new String(bos.toByteArray(), "UTF-8"); } /** * Parses the response and returns the first name of the user. * @throws JSONException if the response is not JSON or if first name does not exist in response */ private String getFirstName(String jsonResponse) throws JSONException { JSONObject profile = new JSONObject(jsonResponse); return profile.getString(NAME_KEY); } }