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.hinj.app.google.plus; 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 android.content.Intent; import android.os.AsyncTask; import android.util.Log; import com.google.android.gms.auth.GoogleAuthUtil; import com.hinj.app.activity.DashBoardActivity; import com.hinj.app.activity.LoginActivity; /** * 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> { private static final String TAG = "TokenInfoTask"; protected LoginActivity mActivity; public static String GOOGLE_USER_DATA = "No_data"; protected String mScope; protected String mEmail; protected int mRequestCode; AbstractGetNameTask(LoginActivity activity, String email, String scope) { this.mActivity = activity; this.mScope = scope; this.mEmail = email; } @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; } protected void onError(String msg, Exception e) { if (e != null) { Log.e(TAG, "Exception: ", e); } } /** * 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. * @return * @return * * @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(); 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(); GOOGLE_USER_DATA = readResponse(is); is.close(); Intent intent = new Intent(mActivity, DashBoardActivity.class); intent.putExtra("email_id", mEmail); mActivity.startActivity(intent); mActivity.finish(); return; } else if (sc == 401) { GoogleAuthUtil.invalidateToken(mActivity, token); onError("Server auth error, please try again.", null); //Toast.makeText(mActivity, "Please try again", Toast.LENGTH_SHORT).show(); //mActivity.finish(); 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"); } }