Android: handling web service authentication
Something you might find yourself doing in Android is web authentication. Most web sites issue a cookie to track session ID's and keep a user logged in. In order to maintain this authentication, you will need to keep cookies synced between activities and between http clients and webviews. The method I ended up doing, which seems to work well enough, was to create a class that extends Application, then define a single HttpClient to be used throughout the rest of the Application. That code looks like:
public class AppSettings extends Application {
private static final DefaultHttpClient client = createClient();
@Override
public void onCreate(){
}
static DefaultHttpClient getClient(){
return client;
}
private static DefaultHttpClient createClient(){
BasicHttpParams params = new BasicHttpParams();
SchemeRegistry schemeRegistry = new SchemeRegistry();
schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
final SSLSocketFactory sslSocketFactory = SSLSocketFactory.getSocketFactory();
schemeRegistry.register(new Scheme("https", sslSocketFactory, 443));
ClientConnectionManager cm = new ThreadSafeClientConnManager(params, schemeRegistry);
DefaultHttpClient httpclient = new DefaultHttpClient(cm, params);
httpclient.getCookieStore().getCookies();
return httpclient;
}
This class also creates an HttpClient that is suitable for AsyncTasks and making multiple simultaneous http requests. Using ThreadSafeClientConnManager for the ClientConnectionManager let's you run http requests inside AsyncTasks without causing a force close when you press the back button and start a second, or third. It also creates a single default cookie store that can be accessed in all your activities. You would use this in your other activities by calling the getClient() method. For example
public class SomeActivity extends Activity {
static DefaultHttpClient mClient = AppSettings.getClient();
...
try {
HttpGet httpget = new HttpGet('URL');
HttpResponse response;
response = mClient.execute(httpget);
...
}
...
}
If you find it necessary to use a webview and need it to access and use the same cookies as your client. You can sync the client's cookie store using CookieManager:
DefaultHttpClient mClient = AppSettings.getClient(); Cookie sessionInfo; Listcookies = mClient.getCookieStore().getCookies(); if (! cookies.isEmpty()){ CookieSyncManager.createInstance(getApplicationContext()); CookieManager cookieManager = CookieManager.getInstance(); for(Cookie cookie : cookies){ sessionInfo = cookie; String cookieString = sessionInfo.getName() + "=" + sessionInfo.getValue() + "; domain=" + sessionInfo.getDomain(); cookieManager.setCookie("example.com", cookieString); CookieSyncManager.getInstance().sync(); } }
You will need to switch example.com with the correct domain.
