Java tutorial
/* * Copyright (C) 2009 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.joelapenna.foursquared.appwidget.stats; import android.content.Context; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.content.pm.PackageManager.NameNotFoundException; import android.util.Log; import com.joelapenna.foursquared.R; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class FoursquareHelper { private static int REQUEST_TIMEOUT = 20;//seconds private static int MILLISECONDS = 1000; private static final String TAG = "FoursquareHelper"; private static final String FOURSQUARE_PAGE = "http://api.foursquare.com/v1/user.json?badges=1&mayor=1"; /** * {@link org.apache.http.StatusLine} HTTP status code when no server error has occurred. */ private static final int HTTP_STATUS_OK = 200; /** * Shared buffer used by {@link #getUrlContent(String)} when reading results * from an API request. */ private static byte[] sBuffer = new byte[512]; /** * User-agent string to use when making requests. Should be filled using * {@link #prepareUserAgent(android.content.Context)} before making any other calls. */ private static String sUserAgent = null; /** * Thrown when there were problems contacting the remote API server, either * because of a network error, or the server returned a bad status code. */ @SuppressWarnings("serial") public static class ApiException extends Exception { public ApiException(String detailMessage, Throwable throwable) { super(detailMessage, throwable); } public ApiException(String detailMessage) { super(detailMessage); } } /** * Thrown when there were problems parsing the response to an API call, * either because the response was empty, or it was malformed. */ @SuppressWarnings("serial") public static class ParseException extends Exception { public ParseException(String detailMessage, Throwable throwable) { super(detailMessage, throwable); } } /** * Prepare the internal User-Agent string for use. This requires a * {@link android.content.Context} to pull the package name and version number for this * application. */ public static void prepareUserAgent(Context context) { try { // Read package name and version number from manifest PackageManager manager = context.getPackageManager(); PackageInfo info = manager.getPackageInfo(context.getPackageName(), 0); sUserAgent = String.format(context.getString(R.string.stats_widget_template_user_agent), info.versionName, info.packageName); } catch (NameNotFoundException e) { Log.e(TAG, "Couldn't find package information in PackageManager", e); } } /** * @throws ApiException If any connection or server error occurs. * @throws ParseException If there are problems parsing the response. */ public static UserStats getContent(String email, String pword) throws ApiException, ParseException { // Query the API for content String content = getUrlContent(FOURSQUARE_PAGE, email, pword); try { //Get JSON objects JSONObject obj = new JSONObject(content); JSONObject userObj = obj.getJSONObject("user"); JSONObject checkinObj = userObj.getJSONObject("checkin"); JSONObject venueObj = checkinObj.getJSONObject("venue"); JSONArray badges = userObj.getJSONArray("badges"); //Get String content String mayorCount = userObj.getString("mayorcount"); String badgeCount = String.valueOf(badges.length()); String venue = venueObj.getString("name"); String userID = userObj.getString(("id")); String firstName = userObj.getString("firstname"); String lastInitial = userObj.getString("lastname").charAt(0) + "."; String userName = firstName + " " + lastInitial; return new UserStats(String.valueOf(mayorCount), badgeCount, venue, userID, userName); } catch (JSONException e) { throw new ParseException("Problem parsing API response", e); } } /** * Pull the raw text content of the given URL. This call blocks until the * operation has completed, and is synchronized because it uses a shared * buffer {@link #sBuffer}. * * @param url The exact URL to request. * @return The raw content returned by the server. * @throws ApiException If any connection or server error occurs. * @author Sections of this code contributed by jTribe (http://jtribe.com.au) */ protected static synchronized String getUrlContent(String sUrl, String email, String pword) throws ApiException { if (sUserAgent == null) { throw new ApiException("User-Agent string must be prepared"); } String userPassword = email + ":" + pword; String encoding = Base64Coder.encodeString(userPassword); try { URL url = new URL(sUrl); System.setProperty("http.keepAlive", "false"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setRequestProperty("Authorization", "Basic " + encoding); connection.setReadTimeout(REQUEST_TIMEOUT * MILLISECONDS); connection.setConnectTimeout(REQUEST_TIMEOUT * MILLISECONDS); connection.setRequestProperty("User-Agent", sUserAgent); connection.setRequestMethod("GET"); //Get response code int responseCode = connection.getResponseCode(); if (responseCode != HTTP_STATUS_OK) { throw new ApiException("Invalid response from server: " + connection.getResponseMessage()); } // Pull content stream from response InputStream inputStream = connection.getInputStream(); ByteArrayOutputStream content = new ByteArrayOutputStream(); // Read response into a buffered stream int readBytes = 0; while ((readBytes = inputStream.read(sBuffer)) != -1) { content.write(sBuffer, 0, readBytes); } // Return result from buffered stream return new String(content.toByteArray()); } catch (IOException e) { throw new ApiException("Problem communicating with API", e); } } }