我真的需要你的帮助。我正在构建一个需要大量HTTP请求的Android应用程序，例如登录到服务器（检查用户是否存在）以及将会话存储到数据库（user_sessions表），添加，更新和删除记录。
在我的登录活动中，我有我的AsyncTask（检查用户是否退出）和其他后台线程（记录用户会话并将用户信息下载到数据库）。这很成功。接下来，当我更新用户信息时，它会成功更新。但是如果我使用我的网络应用更新怎么办？我应该在我的Android应用程序上显示最新更新的信息。我该如何解决这个问题？
这是我到目前为止所尝试的：
private void logSessionToServer() {
// TODO Auto-generated method stub
Thread thread = new Thread(){
public void run(){
strUsername = etUsername.getText().toString();
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair( TAG_USERNAME, strUsername ));
// getting JSON Object
// Note it accepts POST method only
JSONObject json = jsonParser.makeHttpRequest(url_log_session,
"POST", params);
// check log cat from response
Log.d("Create Response", json.toString());
// check for success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
Log.d("", "Successfully logged session!");
} else {
// failed
Log.d("", "Not Successful!");
}
} catch (JSONException e) {
e.printStackTrace();
}
}
};
thread.start();
}
/**
* Background Async Task to Create new record
* */
class LoginTask extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Login.this);
pDialog.setIcon(R.drawable.upload);
pDialog.setTitle("Connecting to server");
pDialog.setMessage("Validating login details..");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
*
* */
protected String doInBackground(String... args) {
strUsername = etUsername.getText().toString();
strPassword = etPassword.getText().toString();
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair( TAG_USERNAME, strUsername ));
params.add(new BasicNameValuePair( TAG_PASSWORD, strPassword ));
// getting JSON Object
// Note it accepts POST method only
JSONObject json = jsonParser.makeHttpRequest(url_login,
"POST", params);
// check log cat from response
Log.d("Create Response", json.toString());
// check for success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
logSessionToServer(); // Save login to server
saveUserInfoToDB(); // Save user info to DB
saveUserloggedIn(); // Save user logged in to preference
savePriestInfoToDB(); // Save priest to DB
Log.d("", "Successful Login!");
Intent i = new Intent(Login.this, MainActivity.class);
startActivity(i);
finish();
} else {
// failed
new Thread()
{
public void run()
{
runOnUiThread(new Runnable()
{
public void run()
{
Toast.makeText(getBaseContext(),
"Not Successful Login", Toast.LENGTH_SHORT).show();
}
});
}
}.start();
Log.d("", "Not Successful Login!");
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String result) {
// dismiss the dialog once done
pDialog.dismiss();
}
}
private void saveUserInfoToDB() {
// TODO Auto-generated method stub
Thread thread = new Thread(){
public void run(){
// Create the array
arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given website URL in JSONfunctions.class
String result = JSONFunctions.getJSONfromURL(url_view_loggedUser_profile);
try {
JSONArray jr = new JSONArray(result);
for(int i=0;i<jr.length();i++)
{
HashMap<String, String> map = new HashMap<String, String>();
jb = (JSONObject)jr.get(i);
map.put(TAG_FIRSTNAME, jb.getString(TAG_FIRSTNAME));
map.put(TAG_MIDDLENAME, jb.getString(TAG_MIDDLENAME));
map.put(TAG_LASTNAME, jb.getString(TAG_LASTNAME));
map.put(TAG_EMAIL, jb.getString(TAG_EMAIL));
map.put(TAG_AGE, jb.getString(TAG_AGE));
map.put(TAG_GENDER, jb.getString(TAG_GENDER));
map.put(TAG_USERNAME, jb.getString(TAG_USERNAME));
map.put(TAG_PASSWORD, jb.getString(TAG_PASSWORD));
map.put(TAG_BARANGAY, jb.getString(TAG_BARANGAY));
map.put(TAG_COMPLETEADDRESS, jb.getString(TAG_COMPLETEADDRESS));
map.put(TAG_CUS_ID, jb.getString(TAG_CUS_ID));
map.put(TAG_REG_DATE, jb.getString(TAG_REG_DATE));
map.put(TAG_BD_MONTH, jb.getString(TAG_BD_MONTH));
map.put(TAG_BD_DATE, jb.getString(TAG_BD_DATE));
map.put(TAG_BD_YEAR, jb.getString(TAG_BD_YEAR));
arraylist.add(map);
String strCusID = jb.getString(TAG_CUS_ID);
String strFname = jb.getString(TAG_FIRSTNAME);
String strMname = jb.getString(TAG_MIDDLENAME);
String strLname = jb.getString(TAG_LASTNAME);
String strEmail = jb.getString(TAG_EMAIL);
String strAge = jb.getString(TAG_AGE);
String strGender = jb.getString(TAG_GENDER);
String strUsername = jb.getString(TAG_USERNAME);
String strPassword = jb.getString(TAG_PASSWORD);
String strBarangay = jb.getString(TAG_BARANGAY);
String strCompleteAddress = jb.getString(TAG_COMPLETEADDRESS);
String strRegDate = jb.getString(TAG_REG_DATE);
String strBDMonth = jb.getString(TAG_BD_MONTH);
String strBDDate = jb.getString(TAG_BD_DATE);
String strBDYear = jb.getString(TAG_BD_YEAR);
try{
dbHelper.insertEntry(strCusID, strFname, strMname, strLname, strEmail,
strAge, strGender, strUsername, strPassword,
strBarangay, strCompleteAddress, strRegDate,
strBDMonth, strBDDate, strBDYear);
Log.d("Response", "Successfully inserted record");
} catch (SQLiteException e) {
Log.d("Response", "Not successful");
}
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
}
};
thread.start();
}
private void savePriestInfoToDB() {
// TODO Auto-generated method stub
Thread thread = new Thread(){
public void run(){
// Create the array
arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given website URL in JSONfunctions.class
String result = JSONFunctions.getJSONfromURL(URL_VIEW_PRIESTS);
try {
JSONArray jr = new JSONArray(result);
for(int i=0;i<jr.length();i++)
{
HashMap<String, String> map = new HashMap<String, String>();
jb = (JSONObject)jr.get(i);
map.put(TAG_P_ID, jb.getString(TAG_P_ID));
map.put(TAG_P_FIRSTNAME, jb.getString(TAG_P_FIRSTNAME));
map.put(TAG_P_MIDDLENAME, jb.getString(TAG_P_MIDDLENAME));
map.put(TAG_P_LASTNAME, jb.getString(TAG_P_LASTNAME));
map.put(TAG_P_EMAIL, jb.getString(TAG_P_EMAIL));
map.put(TAG_P_AGE, jb.getString(TAG_P_AGE));
map.put(TAG_P_ADDRESS, jb.getString(TAG_P_ADDRESS));
map.put(TAG_P_CONTACT, jb.getString(TAG_P_CONTACT));
map.put(TAG_P_STATUS, jb.getString(TAG_P_STATUS));
arraylist.add(map);
String strP_ID = jb.getString(TAG_P_ID);
String strP_Fname = jb.getString(TAG_P_FIRSTNAME);
String strP_Mname = jb.getString(TAG_P_MIDDLENAME);
String strP_Lname = jb.getString(TAG_P_LASTNAME);
String strP_Email = jb.getString(TAG_P_EMAIL);
String strP_Age = jb.getString(TAG_P_AGE);
String strP_Address = jb.getString(TAG_P_ADDRESS);
String strP_Status = jb.getString(TAG_P_STATUS);
String strP_Contact = jb.getString(TAG_P_CONTACT);
try{
dbHelper.insertPriest(strP_ID, strP_Fname, strP_Mname,
strP_Lname, strP_Email, strP_Age,
strP_Address, strP_Status, strP_Contact);
Log.d("Response - Priest", "Successfully inserted record");
} catch (SQLiteException e) {
Log.d("Response - Priest", "Not successful");
}
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
}
};
thread.start();
}
如果这是HTTP请求的最佳做法，请随时查看我的代码并提供反馈。我是Web Services的新手，所以我真的需要你的帮助。任何帮助将不胜感激。感谢
答案 0 :(得分：0)
我刚才说的是：你写了一个每5秒下载一次用户信息的帖子。然后它会将下载的用户信息与您设备上已存储的用户信息进行比较。如果存在差异，则会进行更新，并且您的线程会调用更新的用户信息的新下载。