正在尝试检索SessionId并尝试保存用户会话

Question

我正在开发一个应用程序，需要保存用户会话。。我正在尝试检索用户id，但不知怎么的，我实现的代码似乎不起作用。。我希望当用户打开应用程序时。。该应用程序应该从用户离开的地方打开…并添加新内容…就像在facebook应用程序中一样。。

这是代码。。帮我修复它…在这里使用随机url"https://www.coursera.org/">

public class HttpGetTask extends AsyncTask<Void, Void, String>
    {
        String playCount;
        private static final String eb = "https://www.coursera.org/";
        DefaultHttpClient mClient;
        @Override
        protected String doInBackground(Void... params) {
            // TODO Auto-generated method stub
             mClient = new DefaultHttpClient();
            HttpGet post1 = new HttpGet(eb);
            try
            {

                HttpResponse response = mClient.execute(post1);
                HttpEntity r_entity = response.getEntity();
                String xmlString = EntityUtils.toString(r_entity);
                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                DocumentBuilder db  = factory.newDocumentBuilder();
                InputSource instream = new InputSource();
                instream.setCharacterStream(new StringReader(xmlString));
                org.w3c.dom.Document doc = db.parse(instream);  

                 playCount = "sessionid";
                    NodeList nl = doc.getElementsByTagName("playCount");
                    for(int i = 0;i < nl.getLength();i++)
                    {
                        if(nl.item(i).getNodeType() == org.w3c.dom.Node.ELEMENT_NODE)
                        {
                            org.w3c.dom.Element nameElement = (org.w3c.dom.Element) nl.item(i);
                            playCount = nameElement.getFirstChild().getNodeValue().trim();
                        }
                    }
            }
            catch(ClientProtocolException e)
            {
                e.printStackTrace();
            }
            catch(DOMException e)
            {
                e.printStackTrace();
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
            catch(ParserConfigurationException e)
            {
                e.printStackTrace();
            }
            catch(SAXException e)
            {
                e.printStackTrace();
            }
            return playCount;
        }
        @Override
        protected void onPostExecute(String result) {
            SharedPreferences preferences = getSharedPreferences("com.example.tabsletssee", Context.MODE_PRIVATE);
            preferences.edit().putString("Session",playCount).commit();
            preferences.getString("Session", "");
            super.onPostExecute(result);

        }
    }  

Answer 1

使用SyncAdapter进行离线数据存储

https://developer.android.com/training/sync-adapters/creating-sync-adapter.html