Utility class supporting the Facebook Object.
/*
* Copyright 2010 Facebook, Inc.
*
* 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.facebook.android;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.AlertDialog.Builder;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.webkit.CookieManager;
import android.webkit.CookieSyncManager;
/**
* Utility class supporting the Facebook Object.
*
* @author ssoneff@facebook.com
*
*/
final class Util {
/**
* Generate the multi-part post body providing the parameters and boundary
* string
*
* @param parameters the parameters need to be posted
* @param boundary the random string as boundary
* @return a string of the post body
*/
public static String encodePostBody(Bundle parameters, String boundary) {
if (parameters == null) return "";
StringBuilder sb = new StringBuilder();
for (String key : parameters.keySet()) {
if (parameters.getByteArray(key) != null) {
continue;
}
sb.append("Content-Disposition: form-data; name=\"" + key +
"\"\r\n\r\n" + parameters.getString(key));
sb.append("\r\n" + "--" + boundary + "\r\n");
}
return sb.toString();
}
public static String encodeUrl(Bundle parameters) {
if (parameters == null) {
return "";
}
StringBuilder sb = new StringBuilder();
boolean first = true;
for (String key : parameters.keySet()) {
if (first) first = false; else sb.append("&");
sb.append(URLEncoder.encode(key) + "=" +
URLEncoder.encode(parameters.getString(key)));
}
return sb.toString();
}
public static Bundle decodeUrl(String s) {
Bundle params = new Bundle();
if (s != null) {
String array[] = s.split("&");
for (String parameter : array) {
String v[] = parameter.split("=");
params.putString(URLDecoder.decode(v[0]),
URLDecoder.decode(v[1]));
}
}
return params;
}
/**
* Parse a URL query and fragment parameters into a key-value bundle.
*
* @param url the URL to parse
* @return a dictionary bundle of keys and values
*/
public static Bundle parseUrl(String url) {
// hack to prevent MalformedURLException
url = url.replace("fbconnect", "http");
try {
URL u = new URL(url);
Bundle b = decodeUrl(u.getQuery());
b.putAll(decodeUrl(u.getRef()));
return b;
} catch (MalformedURLException e) {
return new Bundle();
}
}
/**
* Connect to an HTTP URL and return the response as a string.
*
* Note that the HTTP method override is used on non-GET requests. (i.e.
* requests are made as "POST" with method specified in the body).
*
* @param url - the resource to open: must be a welformed URL
* @param method - the HTTP method to use ("GET", "POST", etc.)
* @param params - the query parameter for the URL (e.g. access_token=foo)
* @return the URL contents as a String
* @throws MalformedURLException - if the URL format is invalid
* @throws IOException - if a network problem occurs
*/
public static String openUrl(String url, String method, Bundle params)
throws MalformedURLException, IOException {
// random string as boundary for multi-part http post
String strBoundary = "3i2ndDfv2rTHiSisAbouNdArYfORhtTPEefj3q2f";
String endLine = "\r\n";
OutputStream os;
if (method.equals("GET")) {
url = url + "?" + encodeUrl(params);
}
Log.d("Facebook-Util", method + " URL: " + url);
HttpURLConnection conn =
(HttpURLConnection) new URL(url).openConnection();
conn.setRequestProperty("User-Agent", System.getProperties().
getProperty("http.agent") + " FacebookAndroidSDK");
if (!method.equals("GET")) {
Bundle dataparams = new Bundle();
for (String key : params.keySet()) {
if (params.getByteArray(key) != null) {
dataparams.putByteArray(key, params.getByteArray(key));
}
}
// use method override
if (!params.containsKey("method")) {
params.putString("method", method);
}
if (params.containsKey("access_token")) {
String decoded_token = URLDecoder.decode(params.getString("access_token"));
params.putString("access_token", decoded_token);
}
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="+strBoundary);
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.connect();
os = new BufferedOutputStream(conn.getOutputStream());
os.write(("--" + strBoundary +endLine).getBytes());
os.write((encodePostBody(params, strBoundary)).getBytes());
os.write((endLine + "--" + strBoundary + endLine).getBytes());
if (!dataparams.isEmpty()) {
for (String key: dataparams.keySet()){
os.write(("Content-Disposition: form-data; filename=\"" + key + "\"" + endLine).getBytes());
os.write(("Content-Type: content/unknown" + endLine + endLine).getBytes());
os.write(dataparams.getByteArray(key));
os.write((endLine + "--" + strBoundary + endLine).getBytes());
}
}
os.flush();
}
String response = "";
try {
response = read(conn.getInputStream());
} catch (FileNotFoundException e) {
// Error Stream contains JSON that we can parse to a FB error
response = read(conn.getErrorStream());
}
return response;
}
private static String read(InputStream in) throws IOException {
StringBuilder sb = new StringBuilder();
BufferedReader r = new BufferedReader(new InputStreamReader(in), 1000);
for (String line = r.readLine(); line != null; line = r.readLine()) {
sb.append(line);
}
in.close();
return sb.toString();
}
public static void clearCookies(Context context) {
// Edge case: an illegal state exception is thrown if an instance of
// CookieSyncManager has not be created. CookieSyncManager is normally
// created by a WebKit view, but this might happen if you start the
// app, restore saved state, and click logout before running a UI
// dialog in a WebView -- in which case the app crashes
@SuppressWarnings("unused")
CookieSyncManager cookieSyncMngr =
CookieSyncManager.createInstance(context);
CookieManager cookieManager = CookieManager.getInstance();
cookieManager.removeAllCookie();
}
/**
* Parse a server response into a JSON Object. This is a basic
* implementation using org.json.JSONObject representation. More
* sophisticated applications may wish to do their own parsing.
*
* The parsed JSON is checked for a variety of error fields and
* a FacebookException is thrown if an error condition is set,
* populated with the error message and error type or code if
* available.
*
* @param response - string representation of the response
* @return the response as a JSON Object
* @throws JSONException - if the response is not valid JSON
* @throws Exception - if an error condition is set
*/
public static JSONObject parseJson(String response)
throws JSONException, Exception {
// Edge case: when sending a POST request to /[post_id]/likes
// the return value is 'true' or 'false'. Unfortunately
// these values cause the JSONObject constructor to throw
// an exception.
if (response.equals("false")) {
throw new Exception("request failed");
}
if (response.equals("true")) {
response = "{value : true}";
}
JSONObject json = new JSONObject(response);
// errors set by the server are not consistent
// they depend on the method and endpoint
if (json.has("error")) {
JSONObject error = json.getJSONObject("error");
// throw new Exception("type");
}
if (json.has("error_code") && json.has("error_msg")) {
// throw new Exception(json.getString("error_msg"), "",
// Integer.parseInt(json.getString("error_code")));
}
if (json.has("error_code")) {
// throw new Exception("request failed", "",
// Integer.parseInt(json.getString("error_code")));
}
if (json.has("error_msg")) {
throw new Exception(json.getString("error_msg"));
}
if (json.has("error_reason")) {
throw new Exception(json.getString("error_reason"));
}
return json;
}
/**
* Display a simple alert dialog with the given text and title.
*
* @param context
* Android context in which the dialog should be displayed
* @param title
* Alert dialog title
* @param text
* Alert dialog message
*/
public static void showAlert(Context context, String title, String text) {
Builder alertBuilder = new Builder(context);
alertBuilder.setTitle(title);
alertBuilder.setMessage(text);
alertBuilder.create().show();
}
}
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