I am writing an App that connects to the Fitbit API correctly and pulls back the data I need. I have an Inner class that extends AsyncTask that lets me complete this. So for example, my MainActivity.java opens the Fitbit OAuth2 page and the user logs in. The user is then directed back to the UserActivity.java and their info is displayed.
I now want to add another Activity that pulls back the information for the Activities that they carried out. So, my question is, do I need to add another inner class in my ActivitiesActivity.java or is there some other way to get the data. I know people have used an Interface before but I'm not sure how they work with AsyncTask.
package com.jordan.fitbit_connect;
import android.net.Uri;
import android.os.Bundle;
import android.support.customtabs.CustomTabsIntent;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
String response_type = "token";
String client_id = "22CJH3";
String redirect_uri = "myapplication://login";
String scope = "activity%20nutrition%20heartrate%20location%20nutrition%20profile%20settings%20sleep%20social%20weight";
String url = "https://www.fitbit.com/oauth2/authorize?" + "response_type=" + response_type + "&client_id=" + client_id + "&redirect_uri=" + redirect_uri + "&scope=" + scope;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//
// CustomTabsIntent customTabsIntent = new CustomTabsIntent.Builder().build();
// customTabsIntent.launchUrl(this, Uri.parse(url));
connectToFitbit();
}
public void connectToFitbit()
{
Button btn = (Button)findViewById(R.id.btnConnect);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
CustomTabsIntent customTabsIntent = new CustomTabsIntent.Builder().build();
customTabsIntent.launchUrl(getApplicationContext(), Uri.parse(url));
}
});
}
}
package com.jordan.fitbit_connect;
import android.content.Intent;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class TestActivity extends AppCompatActivity
{
//String to hold the data sent back by the Intent
String string;
//String to extract the token from 'string' above
private static String token;
//Strings to get the data from the JSON Object
public static String name, avatar, age, weight, height;
TextView username, txtAge, txtWeight, txtHeight, txtBMI;
float bmi;
ImageView imgViewAvatar;
//-------------------------------------- START onNewIntent()------------------------------------
/*
This method returns the URI from the Intent as an encoded String
*/
#Override
protected void onNewIntent(Intent intent)
{
string = intent.getDataString();
}
//-------------------------------------- END onNewIntent()--------------------------------------
//-------------------------------------- START onCreate()---------------------------------------
/*
Default method when the class is created
*/
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
onNewIntent(getIntent());
token = string.substring(string.indexOf("&access_token")+36,308);
Log.i("TAG", "Access Token: "+ token);
Log.i("TAG", "Data String: " + string);
//new JSONTask().execute("https://api.fitbit.com/1.2/user/-/sleep/date/2017-10-26.json");
//new JSONTask().execute("https://api.fitbit.com/1/user/-/activities/steps/date/today/6m.json");
new JSONTask().execute("https://api.fitbit.com/1/user/-/profile.json");
}
//-------------------------------------- END onCreate()-----------------------------------------
//-------------------------------------- START of inner class JSONTask -------------------------
public class JSONTask extends AsyncTask<String,String,String>
{
#Override
protected void onPreExecute() {
super.onPreExecute();
username = (TextView)findViewById(R.id.txtUser);
imgViewAvatar = (ImageView)findViewById(R.id.imgViewAvatar);
txtAge = (TextView)findViewById(R.id.txtAge);
txtWeight = (TextView) findViewById(R.id.txtWeight);
txtHeight = (TextView) findViewById(R.id.txtHeight);
txtBMI = (TextView) findViewById(R.id.txtBMI);
}
//-------------------------------------- START doInBackground()-----------------------------
/*
This method is what happens on the background thread when the
app is running. It will
*/
#Override
protected String doInBackground(String... params)
{
HttpURLConnection connection = null;
BufferedReader reader = null;
try
{
URL url = new URL(params[0]);
connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("GET");
connection.setDoOutput(false);
connection.addRequestProperty("Authorization", "Bearer " + token);
connection.connect();
InputStream stream = (InputStream)connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while((line = reader.readLine()) !=null)
{
buffer.append(line);
}
return buffer.toString();
} catch (MalformedURLException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.toString();
}
return null;
}
//-------------------------------------- END doInBackground()-------------------------------
//-------------------------------------- START onPostExecute()------------------------------
#Override
protected void onPostExecute(String data)
{
super.onPostExecute(data);
Log.i("TAG", data);
try
{
//GET ALL THE JSON DATA
JSONObject allData = new JSONObject(data);
//GET THE USERNAME
JSONObject userObject = allData.getJSONObject("user");
name = userObject.getString("fullName");
username.append(" "+name);
//GET THE USER'S AVATAR
avatar = userObject.getString("avatar640");
Picasso.get().load(avatar).into(imgViewAvatar);
//GET THE USER'S AGE
age = userObject.getString("age");
txtAge.append(" "+age);
weight = userObject.getString("weight");
txtWeight.append(" "+weight);
float weightFloat = Float.parseFloat(weight);
height = userObject.getString("height");
txtHeight.append(" "+height);
float heightFloat= Float.parseFloat(height)/100;
bmi = (float)(weightFloat/(heightFloat * heightFloat));
if(bmi <= 16)
{
txtBMI.setTextColor(Color.YELLOW);
txtBMI.append(" "+ String.valueOf(bmi) + " - You are severely underweight!");
}
else if(bmi <= 18.5)
{
txtBMI.setTextColor(Color.GRAY);
txtBMI.append(" "+ String.valueOf(bmi) + " - You are underweight!");
}
else if(bmi <= 25)
{
txtBMI.setTextColor(Color.GREEN);
txtBMI.append(" "+ String.valueOf(bmi) + " - Your weight is normal");
}
else if(bmi <= 30)
{
txtBMI.setTextColor(Color.parseColor("#FFA500"));
txtBMI.append(" "+ String.valueOf(bmi) + " - You are overweight!");
}
else
{
txtBMI.setTextColor(Color.RED);
txtBMI.append(" " + String.valueOf(bmi) + " - You are obese!");
}
// for(int i =0; i< userObject.length(); i++) {
//3.DECLARE ANOTHER JSONOBJECT THAT EXTRACTS THE OBECT FROM THE SPECIFIED ARRAY
//JSONObject sleep = sleepArray.getJSONObject(i);
//4.Then use a getString to get the data from the object
//name = userObject.getString("firstName");
// Log.i("TAG",name);
}
catch (JSONException e)
{
e.printStackTrace();
}
}
}
//-------------------------------------- END of inner class JSONTask ---------------------------
}
One of the methods using AsynTask in different Activities, creating a callback interface.
Create a callback interface
interface AsyncTaskListener<T> {
public void onComplete(T result);
}
Then in your MainActivity and TestActivity:
public class MainActivity extends AppCompatActivity
implements AsyncTaskListener<String> {
public void onComplete(String result) {
// your staff here
}
}
public class TestActivity extends AppCompatActivity
implements AsyncTaskListener<String> {
public void onComplete(String result) {
// your staff here
}
}
And add to your AsyncTask class:
public class JSONTask extends AsyncTask<String, String, String>
private AsyncTaskListener<String> listener;
public JSONTask (AsyncTaskListener<String> callback) {
this.listener = callback;
}
protected void onPostExecute(String result) {
listener.onComplete(result); // calling onComplate interface
}
Related
I tried to write a "login" App using MVP model. And I use WAMP to build up my server. I'm sure that my php documents have no problem.
Here is the structure of my App:
enter image description here
And here are the files:
User.java
package com.example.android.login.mvp;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
import com.example.android.login.R;
import com.example.android.login.mvp.bean.User;
import com.example.android.login.mvp.presenter.UserLoginPresenter;
import com.example.android.login.mvp.view.IUserLoginView;
public class UserLoginActivity extends AppCompatActivity implements IUserLoginView
{
private EditText mEtUsername, mEtPassword;
private Button mBtnLogin, mBtnClear;
private ProgressBar mPbLoading;
private UserLoginPresenter mUserLoginPresenter = new UserLoginPresenter(this);
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_login);
initViews();
}
private void initViews()
{
mEtUsername = (EditText) findViewById(R.id.id_et_username);
mEtPassword = (EditText) findViewById(R.id.id_et_password);
mBtnClear = (Button) findViewById(R.id.id_btn_clear);
mBtnLogin = (Button) findViewById(R.id.id_btn_login);
mPbLoading = (ProgressBar) findViewById(R.id.id_pb_loading);
mBtnLogin.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
mUserLoginPresenter.login();
}
});
mBtnClear.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
mUserLoginPresenter.clear();
}
});
}
#Override
public String getUserName()
{
return mEtUsername.getText().toString();
}
#Override
public String getPassword()
{
return mEtPassword.getText().toString();
}
#Override
public void clearUserName()
{
mEtUsername.setText("");
}
#Override
public void clearPassword()
{
mEtPassword.setText("");
}
#Override
public void showLoading()
{
mPbLoading.setVisibility(View.VISIBLE);
}
#Override
public void hideLoading()
{
mPbLoading.setVisibility(View.GONE);
}
#Override
public void toMainActivity(User user)
{
Toast.makeText(this, user.getUsername() +
" login success , to MainActivity", Toast.LENGTH_SHORT).show();
}
#Override
public void showFailedError()
{
Toast.makeText(this,
"login failed", Toast.LENGTH_SHORT).show();
}
}
IUserBiz.java
package com.example.android.login.mvp.biz;
/**
* Created by zhy on 15/6/19.
*/
public interface IUserBiz
{
public void login(String username, String password, OnLoginListener loginListener);
}
OnLoginListener.java
package com.example.android.login.mvp.biz;
import com.example.android.login.mvp.bean.User;
/**
* Created by zhy on 15/6/19.
*/
public interface OnLoginListener
{
void loginSuccess(User user);
void loginFailed();
}
UserBiz.java
package com.example.android.login.mvp.biz;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import com.example.android.login.R;
import com.example.android.login.mvp.bean.User;
/**
* Created by zhy on 15/6/19.
*/
public class UserBiz extends AppCompatActivity implements IUserBiz
{
private User user;
private OnLoginListener loginListener;
#Override
public void login(final String username, final String password, final OnLoginListener mLoginListener)
{
user = new User();
user.setUsername(username);
user.setPassword(password);
user.setStatus(0);
loginListener = mLoginListener;
LoginAsyncTask task = new LoginAsyncTask();
String test1Url = getString(R.string.server_ip)+"/server/login.php";
task.execute(test1Url);
}
/**
* Update the UI with the given earthquake information.
*/
private void updateUi(User mUser) {
if (mUser.getStatus()==1)
{
loginListener.loginSuccess(user);
} else
{
loginListener.loginFailed();
}
}
private class LoginAsyncTask extends AsyncTask<String, Void, User> {
#Override
protected User doInBackground(String... urls) {
if (urls.length < 1 || urls[0] == null) {
return null;
}
// Perform the HTTP request for earthquake data and process the response.
User mUser = Utils.fetchEarthquakeData(urls[0],user);
return mUser;
}
#Override
protected void onPostExecute(User result) {
if(result==null){
return;
}
updateUi(result);
}
}
}
Utils.java
package com.example.android.login.mvp.biz;
import android.text.TextUtils;
import android.util.Log;
import com.example.android.login.mvp.bean.User;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
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.nio.charset.Charset;
/**
* Utility class with methods to help perform the HTTP request and
* parse the response.
*/
public final class Utils {
/** Tag for the log messages */
public static final String LOG_TAG = Utils.class.getSimpleName();
/**
* Query the USGS dataset and return an {#link User} object to represent a single earthquake.
*/
public static User fetchEarthquakeData(String requestUrl, User user) {
// Create URL object
URL url = createUrl(requestUrl);
// Perform HTTP request to the URL and receive a JSON response back
String jsonResponse = null;
try {
jsonResponse = makeHttpRequest(url, user);
} catch (IOException e) {
Log.e(LOG_TAG, "Error closing input stream", e);
}
// Extract relevant fields from the JSON response and create an {#link User} object
User earthquake = extractFeatureFromJson(jsonResponse);
// Return the {#link User}
return earthquake;
}
/**
* Returns new URL object from the given string URL.
*/
private static URL createUrl(String stringUrl) {
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException e) {
Log.e(LOG_TAG, "Error with creating URL ", e);
}
return url;
}
/**
* Make an HTTP request to the given URL and return a String as the response.
*/
private static String makeHttpRequest(URL url, User user) throws IOException {
String jsonResponse = "";
// If the URL is null, then return early.
if (url == null) {
return jsonResponse;
}
HttpURLConnection urlConnection = null;
InputStream inputStream = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setReadTimeout(10000 /* milliseconds */);
urlConnection.setConnectTimeout(15000 /* milliseconds */);
urlConnection.setRequestMethod("POST");
urlConnection.setDoOutput(true);
String params="app_user_name="+user.getUsername()+'&'+"app_password="+user.getPassword();
OutputStream out=urlConnection.getOutputStream();
out.write(params.getBytes());//post提交参数
out.flush();
out.close();
// If the request was successful (response code 200),
// then read the input stream and parse the response.
if (urlConnection.getResponseCode() == 200) {
inputStream = urlConnection.getInputStream();
jsonResponse = readFromStream(inputStream);
} else {
Log.e(LOG_TAG, "Error response code: " + urlConnection.getResponseCode());
}
} catch (IOException e) {
Log.e(LOG_TAG, "Problem retrieving the earthquake JSON results.", e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
inputStream.close();
}
}
return jsonResponse;
}
/**
* Convert the {#link InputStream} into a String which contains the
* whole JSON response from the server.
*/
private static String readFromStream(InputStream inputStream) throws IOException {
StringBuilder output = new StringBuilder();
if (inputStream != null) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, Charset.forName("UTF-8"));
BufferedReader reader = new BufferedReader(inputStreamReader);
String line = reader.readLine();
while (line != null) {
output.append(line);
line = reader.readLine();
}
}
return output.toString();
}
/**
* Return an {#link User} object by parsing out information
* about the first earthquake from the input earthquakeJSON string.
*/
private static User extractFeatureFromJson(String earthquakeJSON) {
// If the JSON string is empty or null, then return early.
if (TextUtils.isEmpty(earthquakeJSON)) {
return null;
}
try {
JSONObject baseJsonResponse = new JSONObject(earthquakeJSON);
// If there are results in the features array
if (baseJsonResponse.length() > 0) {
int status = baseJsonResponse.getInt("status");
// Create a new {#link User} object
User user=new User();
user.setStatus(status);
return user;
}
} catch (JSONException e) {
Log.e(LOG_TAG, "Problem parsing the earthquake JSON results", e);
}
return null;
}
}
UserLoginPresenter.java
package com.example.android.login.mvp.presenter;
import com.example.android.login.mvp.bean.User;
import com.example.android.login.mvp.biz.IUserBiz;
import com.example.android.login.mvp.biz.OnLoginListener;
import com.example.android.login.mvp.biz.UserBiz;
import com.example.android.login.mvp.view.IUserLoginView;
/**
* Created by zhy on 15/6/19.
*/
public class UserLoginPresenter {
private IUserBiz userBiz;
private IUserLoginView userLoginView;
public UserLoginPresenter(IUserLoginView userLoginView) {
this.userLoginView = userLoginView;
this.userBiz = new UserBiz();
}
public void login() {
userLoginView.showLoading();
userBiz.login(userLoginView.getUserName(), userLoginView.getPassword(), new OnLoginListener() {
#Override
public void loginSuccess(final User user) {
userLoginView.toMainActivity(user);
userLoginView.hideLoading();
}
#Override
public void loginFailed() {
userLoginView.showFailedError();
userLoginView.hideLoading();
}
});
}
public void clear() {
userLoginView.clearUserName();
userLoginView.clearPassword();
}
}
IUserLoginView.java
package com.example.android.login.mvp.view;
import com.example.android.login.mvp.bean.User;
/**
* Created by zhy on 15/6/19.
*/
public interface IUserLoginView
{
String getUserName();
String getPassword();
void clearUserName();
void clearPassword();
void showLoading();
void hideLoading();
void toMainActivity(User user);
void showFailedError();
}
UserLoginActivity.java
package com.example.android.login.mvp;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
import com.example.android.login.R;
import com.example.android.login.mvp.bean.User;
import com.example.android.login.mvp.presenter.UserLoginPresenter;
import com.example.android.login.mvp.view.IUserLoginView;
public class UserLoginActivity extends AppCompatActivity implements IUserLoginView
{
private EditText mEtUsername, mEtPassword;
private Button mBtnLogin, mBtnClear;
private ProgressBar mPbLoading;
private UserLoginPresenter mUserLoginPresenter = new UserLoginPresenter(this);
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_login);
initViews();
}
private void initViews()
{
mEtUsername = (EditText) findViewById(R.id.id_et_username);
mEtPassword = (EditText) findViewById(R.id.id_et_password);
mBtnClear = (Button) findViewById(R.id.id_btn_clear);
mBtnLogin = (Button) findViewById(R.id.id_btn_login);
mPbLoading = (ProgressBar) findViewById(R.id.id_pb_loading);
mBtnLogin.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
mUserLoginPresenter.login();
}
});
mBtnClear.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
mUserLoginPresenter.clear();
}
});
}
#Override
public String getUserName()
{
return mEtUsername.getText().toString();
}
#Override
public String getPassword()
{
return mEtPassword.getText().toString();
}
#Override
public void clearUserName()
{
mEtUsername.setText("");
}
#Override
public void clearPassword()
{
mEtPassword.setText("");
}
#Override
public void showLoading()
{
mPbLoading.setVisibility(View.VISIBLE);
}
#Override
public void hideLoading()
{
mPbLoading.setVisibility(View.GONE);
}
#Override
public void toMainActivity(User user)
{
Toast.makeText(this, user.getUsername() +
" login success , to MainActivity", Toast.LENGTH_SHORT).show();
}
#Override
public void showFailedError()
{
Toast.makeText(this,
"login failed", Toast.LENGTH_SHORT).show();
}
}
But I got something wrong like this:
enter image description here
I have no idea about it. How to solve it?
the issue is here
this.userBiz = new UserBiz();
UserBiz is an activity so activity gets their context when they are being started with Intent (by OS) but creating an object of an activity will not provide any contenxt hence the null exception at
#Override
public void login(final String username, final String password, final OnLoginListener mLoginListener)
{
user = new User();
user.setUsername(username);
user.setPassword(password);
user.setStatus(0);
loginListener = mLoginListener;
LoginAsyncTask task = new LoginAsyncTask();
String test1Url = getString(R.string.server_ip)+"/server/login.php";
// no context here due to new UserBiz
// getString required context
task.execute(test1Url);
}
Solution : you can use enums or static final constants to avoid context and also would be wise to substitute UserBiz as separate class instead of an activity
I am trying to make an app which uses last.fm's web API, sends a query for similar artists and returns all the names of the similar artists. It seems as though I manage to connect and get the xml response properly. However, I cannot extract the value of the name-attribute. I am using artistName = xmlData.getAttributeValue(null, "name"); but all it gives me is null.
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.*;
#SuppressWarnings("FieldCanBeLocal")
public class MainActivity extends Activity implements Observer {
private final String INPUTERROR = "Invalid/missing artist name.";
private NetworkCommunication nc;
private ArrayList<String> list;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nc = new NetworkCommunication();
nc.register(this);
list = new ArrayList<>();
ListView lv = (ListView)findViewById(R.id.ListView_similarArtistsList);
ArrayAdapter adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, list);
lv.setAdapter(adapter);
}
public void searchButton_Clicked(View v){
EditText inputField = (EditText)findViewById(R.id.editText_artistName);
String searchString = inputField.getText().toString();
searchString = cleanSearchString(searchString);
if(validateSearchString(searchString)){
nc.setSearchString(searchString);
nc.execute();
}
else{
Toast.makeText(MainActivity.this, INPUTERROR, Toast.LENGTH_SHORT).show();
}
}
private String cleanSearchString(String oldSearchString){
String newString = oldSearchString.trim();
newString = newString.replace(" ", "");
return newString;
}
private boolean validateSearchString(String searchString){
boolean rValue = true;
if(TextUtils.isEmpty(searchString)){
rValue = false;
}
return rValue;
}
#Override
public void update(String artistName) {
list.add(artistName);
}
}
Here is my Network Communications class:
import android.os.AsyncTask;
import android.util.Log;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
#SuppressWarnings("FieldCanBeLocal")
class NetworkCommunication extends AsyncTask<Object, String, Integer> implements Subject {
private final String MYAPIKEY = "--------------------------";
private final String ROOT = "http://ws.audioscrobbler.com/2.0/";
private final String METHOD = "?method=artist.getsimilar";
private ArrayList<Observer> observers;
private int amountOfArtists = 0;
private String foundArtistName;
private String searchString;
NetworkCommunication(){
observers = new ArrayList<>();
}
void setSearchString(String newSearchString){
searchString = newSearchString;
}
private XmlPullParser sendRequest(){
try{
URL url = new URL(ROOT + METHOD + "&artist=" + searchString + "&api_key=" + MYAPIKEY);
XmlPullParser receivedData = XmlPullParserFactory.newInstance().newPullParser();
receivedData.setInput(url.openStream(), null);
return receivedData;
}
catch (IOException | XmlPullParserException e){
Log.e("ERROR", e.getMessage(), e);
}
return null;
}
private int tryProcessData(XmlPullParser xmlData){
int artistsFound = 0;
String artistName;
int eventType;
try{
while ((eventType = xmlData.next()) != XmlPullParser.END_DOCUMENT) {
if (eventType == XmlPullParser.START_TAG) {
if(xmlData.getName().equals("name")){
artistName = xmlData.getAttributeValue(null, "name");
publishProgress(artistName);
artistsFound++;
}
}
}
}
catch (IOException | XmlPullParserException e){
Log.e("ERROR", e.getMessage(), e);
}
if (artistsFound == 0) {
publishProgress();
}
return artistsFound;
}
#Override
protected Integer doInBackground(Object... params) {
XmlPullParser data = sendRequest();
if(data != null){
return tryProcessData(data);
}
else{
return null;
}
}
#Override
protected void onProgressUpdate(String... values){
/*
if (values.length == 0) {
//No data found...
}
*/
if (values.length == 1) {
setFoundArtistName(values[0]);
notifyObserver();
}
super.onProgressUpdate(values);
}
private void setFoundArtistName(String newArtistName){
foundArtistName = newArtistName;
}
#Override
public void register(Observer newObserver) {
observers.add(newObserver);
}
#Override
public void unregister(Observer deleteObserver) {
observers.remove(deleteObserver);
}
#Override
public void notifyObserver() {
for (Observer o : observers) {
Log.i("my tag.... ", "name = " + foundArtistName);
o.update(foundArtistName);
}
}
}
Here's a screenshot of the xml response in Google Chrome:
The only thing I am interested in extracting at this moment is the the value of the Name-Element.
I am logging the value of foundArtistName (in the method notifyObserver) it gives me A LOT of "my tag.... name = null my tag.... name = null my tag.... name = null etc.."
EDIT: I tried using getText() instead of getAttributeValue(), but it also gives me null.
I found the solution. I was using: artistName = xmlData.getAttributeValue(null, "name");, when I really should've used: artistName = xmlData.nextText();
While working on a project I'm getting this error
Error : method gettext() must be call from UI thread is worker
on the following line :
String url = Util.send_chat_url+"?email_id="+editText_mail_id.getText().toString()+"&message="+editText_chat_message.getText().toString();
Please Help
This is my entire code for the class ChatActivity.java
package com.example.ankit.myapplication;
import android.app.Activity;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.support.annotation.NonNull;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import com.example.ankit.myapplication.XmppService;
import com.squareup.okhttp.OkHttpClient;
import org.jivesoftware.smack.packet.Message;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Scanner;
//import services.XmppService;
public class ChatActivity extends Activity {
EditText editText_mail_id;
EditText editText_chat_message;
ListView listView_chat_messages;
Button button_send_chat;
List<ChatObject> chat_list;
BroadcastReceiver recieve_chat;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat);
Scanner in = new Scanner(System.in);
XmppService xm= new XmppService();
Log.d("pavan","in chat "+getIntent().getStringExtra("user_id"));
Log.d("pavan","in chat server "+Util.SERVER);
XmppService.setupAndConnect(ChatActivity.this, Util.SERVER, "",
getIntent().getStringExtra("user_id"), Util.XMPP_PASSWORD);
editText_mail_id= (EditText) findViewById(R.id.editText_mail_id);
editText_chat_message= (EditText) findViewById(R.id.editText_chat_message);
listView_chat_messages= (ListView) findViewById(R.id.listView_chat_messages);
button_send_chat= (Button) findViewById(R.id.button_send_chat);
button_send_chat.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// send chat message to server
String message=editText_chat_message.getText().toString();
showChat("sent",message);
// new SendMessage().execute();
XmppService.sendMessage(ChatActivity.this, editText_mail_id.getText().toString() + Util.SUFFIX_CHAT, Message.Type.chat, message);
editText_chat_message.setText("");
}
});
recieve_chat=new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String message=intent.getStringExtra("message");
Log.d("pavan","in local braod "+message);
showChat("recieve",message);
}
};
LocalBroadcastManager.getInstance(this).registerReceiver(recieve_chat, new IntentFilter("message_recieved"));
}
private void showChat(String type, String message){
if(chat_list==null || chat_list.size()==0){
chat_list= new ArrayList<ChatObject>();
}
chat_list.add(new ChatObject(message,type));
ChatAdabter chatAdabter=new ChatAdabter(ChatActivity.this,R.layout.chat_view,chat_list);
listView_chat_messages.setAdapter(chatAdabter);
//chatAdabter.notifyDataSetChanged();
}
#Override
protected void onDestroy() {
super.onDestroy();
}
private class SendMessage extends AsyncTask<String, Void, String> {
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
}
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
String url = Util.send_chat_url+"?email_id="+editText_mail_id.getText().toString()+"&message="+editText_chat_message.getText().toString();
Log.i("pavan", "url" + url);
OkHttpClient client_for_getMyFriends = new OkHttpClient();
String response = null;
// String response=Utility.callhttpRequest(url);
try {
url = url.replace(" ", "%20");
response = callOkHttpRequest(new URL(url),
client_for_getMyFriends);
for (String subString : response.split("<script", 2)) {
response = subString;
break;
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return response;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
//Toast.makeText(context,"response "+result,Toast.LENGTH_LONG).show();
}
}
// Http request using OkHttpClient
String callOkHttpRequest(URL url, OkHttpClient tempClient)
throws IOException {
HttpURLConnection connection = tempClient.open(url);
connection.setConnectTimeout(40000);
InputStream in = null;
try {
// Read the response.
in = connection.getInputStream();
byte[] response = readFully(in);
return new String(response, "UTF-8");
} finally {
if (in != null)
in.close();
}
}
byte[] readFully(InputStream in) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
for (int count; (count = in.read(buffer)) != -1;) {
out.write(buffer, 0, count);
}
return out.toByteArray();
}
}
Do not access the Android UI toolkit from outside the UI thread
Pass editText_mail_id.getText() and editText_chat_message.getText() as parameters to your async task or set it in onPreExecute to some variable
Like :
private class SendMessage extends AsyncTask<String, Void, String> {
private String mailId;
private String msgText;
#Override
protected void onPreExecute() {
super.onPreExecute();
mailId = editText_mail_id.getText().toString();
msgText = editText_chat_message.getText().toString();
}
Change url in doInBackground as :
String url = Util.send_chat_url+"?email_id="+mailId+"&message="+msgText;
you can create class for storing your parameter like i do,
Just create one class
example :
public class MyTaskParams
{
String mailId;
String message;
public MyTaskParams(String mailId, String message)
{
this.mailId = mailId;
this.message = message;
}
}
public class SendMessage extends AsyncTask<MyTaskParams, Void, String {
#Override
protected String doInBackground(MyTaskParams... params) {
String mailId = params[0].mailId;
String message = params[0].message;
String url = Util.send_chat_url+"?email_id="+ mailId +"&message="+ message;
}
}
so you can just call like this
MyTaskParams params = new MyTaskParams(editText_mail_id.getText().toString(),editText_chat_message.getText().toString());
SendMessage myTask = new SendMessage();
myTask.execute(params);
with this code you can call SendMessage Class from any activity, dont bind your asynctask with get text because if you do that you just can use SendMessage only in that activity
Hope this can help you.
![here there are 3 edit text box. where i am using json to check the login id and password details and another text box is for the selection of the server address. the only criteria is that all these should be done with a single button ie the login button.
can any one help me with the code]1
the code is as follows
package com.example.catxam;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import com.example.catxam.JSONParser;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.EditText;
import android.view.Window;
import android.view.WindowManager;
import android.widget.TextView;
public class Login extends Activity {
private EditText inputUserid, inputPassword, server;
TextView forgotPassword;
private Button b1;
public String serve;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String Flag = "flag";
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.login);
inputUserid = (EditText) findViewById(R.id.Username_edit);
inputPassword = (EditText) findViewById(R.id.User_password);
server = (EditText) findViewById(R.id.serverSelection);
forgotPassword = (TextView) findViewById(R.id.forgotPassword);
forgotPassword.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent passForget = new Intent(getApplicationContext(),
ForgotPassword.class);
startActivity(passForget);
}
});
b1 = (Button) findViewById(R.id.loginbutton); // login button
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
new CreateNewUser().execute();
new SelectServerAddress().execute();
}
});
}
// this class is for selection of the server address
class SelectServerAddress extends AsyncTask<String, String, String>{
#Override
protected String doInBackground(String... arg0) {
return null;
}
}
// this class is for the checking of the user login and password
//i.e. of first login and the next consecutive logins
class CreateNewUser extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Login.this);
pDialog.setMessage("Checking..");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Checking creditenials
* */
protected String doInBackground(String... args) {
String user = inputUserid.getText().toString();
String pswrd = inputPassword.getText().toString();
//if (serve == "")
//{
//serve = "192.168.0.101/gly_prov_V1";
//}
//else
//{
//serve = "glydenlewis.esy.es";
//}
// URL to check username & password
final String url_check_user = "http://" + serve +"/gly_prov_V1/android_check.php";
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("uname", user));
params.add(new BasicNameValuePair("psd", pswrd));
params.add(new BasicNameValuePair("server",serve));
// getting JSON Object
// Note that create product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_check_user,
"POST", params);
// check log cat from response
Log.d("Create Response", json.toString());
// check for success tag
try {
int success = json.getInt(TAG_SUCCESS);
int flag_ck = json.getInt(Flag);
if (success == 1) {
if (flag_ck == 0)
{
//First Time Login By User
Intent i = new Intent(getApplicationContext(), UpdateDetails.class);
startActivity(i);
finish(); // closing this screen
}
else
{
// successfully login
Intent i = new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
finish(); // closing this screen
}
} else {
Toast.makeText(getApplicationContext(), "Wrong Credentials", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
}
You can execute tasks in serial manner. Take the output of first task as input to the second task.
But you have to implement a cancel mechanism if the activity is destroyed while your tasks is actually running. a simple approach is to make tasks references as a class member and cancel it when activity's onStop() method is called.
class static SelectServerAddress extends AsyncTask<String, String, String>{
#Override
protected String doInBackground(String... urls) {
return getAddress(urls[0]);
}
#Override
protected void onPostExecute(String serverAddress) {
// Call login service
mLoginTask = new CreateNewUser(serverAddress);
mLoginTask.execute();
}
}
Edit:
Update button click listener code to this:
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
new SelectServerAdress().execute();
}
});
Then update SelectServerAdress class and add this method:
#Override
protected void onPostExecute(String serverAddress) {
serve = serverAddress;
new SelectServerAddress().execute();
}
I need to show toast message when the server is not responding
when I press the login button, some parameters are passed to AgAppMenu screen which use url connection to server and get xml response in AgAppHelperMethods screen. The
probelm is when the server is busy or the network is not avaibale, I can't show toast message on catch block although it shows the log message.
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Intent ;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class LoginScreen extends Activity implements OnClickListener {
EditText mobile;
EditText pin;
Button btnLogin;
Button btnClear;
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.agapplogin);
TextView lblMobileNo = (TextView) findViewById(R.id.lblMobileNo);
lblMobileNo.setTextColor(getResources()
.getColor(R.color.text_color_red));
mobile = (EditText) findViewById(R.id.txtMobileNo);
TextView lblPinNo = (TextView) findViewById(R.id.lblPinNo);
lblPinNo.setTextColor(getResources().getColor(R.color.text_color_red));
pin = (EditText) findViewById(R.id.txtPinNo);
btnLogin = (Button) findViewById(R.id.btnLogin);
btnClear = (Button) findViewById(R.id.btnClear);
btnLogin.setOnClickListener(new OnClickListener() {
public void onClick(View view) {
postLoginData();
}
});
btnClear.setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
cleartext();
}
});
/*
*
* btnClear.setOnClickListener(new OnClickListener() { public void
* onClick(View arg0) {
*
* } });
*/
}
public void postLoginData()
{
if (pin.getTextSize() == 0 || mobile.getTextSize() == 0) {
AlertDialog.Builder altDialog = new AlertDialog.Builder(this);
altDialog.setMessage("Please Enter Complete Information!");
} else {
Intent i = new Intent(this.getApplicationContext(), AgAppMenu.class);
Bundle bundle = new Bundle();
bundle.putString("mno", mobile.getText().toString());
bundle.putString("pinno", pin.getText().toString());
i.putExtras(bundle);
startActivity(i);
}
}
#Override
public void onClick(View v) {
}
public void cleartext() {
{
pin.setText("");
mobile.setText("");
}
}
}
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class AgAppMenu extends Activity {
String mno, pinno;
private String[][] xmlRespone;
Button btnMiniStatement;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.agappmenu);
mno = getIntent().getExtras().getString("mno");
pinno = getIntent().getExtras().getString("pinno");
setTitle("Welcome to the Ag App Menu");
AgAppHelperMethods agapp =new AgAppHelperMethods();
// xmlRespone = AgAppHelperMethods.AgAppXMLParser("AG_IT_App/AgMainServlet?messageType=LOG&pin=" + pinno + "&mobile=" + mno + "&source=" + mno + "&channel=INTERNET");
xmlRespone = agapp.AgAppXMLParser("AG_IT_App/AgMainServlet?messageType=LOG&pin=" + pinno + "&mobile=" + mno + "&source=" + mno + "&channel=INTERNET");
import java.net.URL;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import android.view.View;
import android.view.View.OnKeyListener;
public class AgAppHelperMethods extends Activity {
private static final String LOG_TAG = null;
private static AgAppHelperMethods instance = null;
public static String varMobileNo;
public static String varPinNo;
String[][] xmlRespone = null;
boolean flag = true;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.agapphelpermethods);
}
protected AgAppHelperMethods() {
}
public static AgAppHelperMethods getInstance() {
if (instance == null) {
instance = new AgAppHelperMethods();
}
return instance;
}
public static String getUrl() {
String url = "https://demo.accessgroup.mobi/";
return url;
}
public String[][] AgAppXMLParser(String parUrl) {
String _node, _element;
String[][] xmlRespone = null;
try {
String url = AgAppHelperMethods.getUrl() + parUrl;
URL finalUrl = new URL(url);
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new InputSource(finalUrl.openStream()));
doc.getDocumentElement().normalize();
NodeList list = doc.getElementsByTagName("*");
_node = new String();
_element = new String();
xmlRespone = new String[list.getLength()][2];
// this "for" loop is used to parse through the
// XML document and extract all elements and their
// value, so they can be displayed on the device
for (int i = 0; i < list.getLength(); i++) {
Node value = list.item(i).getChildNodes().item(0);
_node = list.item(i).getNodeName();
_element = value.getNodeValue();
xmlRespone[i][0] = _node;
xmlRespone[i][1] = _element;
}// end for
throw new ArrayIndexOutOfBoundsException();
}// end try
// will catch any exception thrown by the XML parser
catch (Exception e) {
Toast.makeText(AgAppHelperMethods.this,
"error server not responding " + e.getMessage(),
Toast.LENGTH_SHORT).show();
Log.e(LOG_TAG, "CONNECTION ERROR FUNDAMO SERVER NOT RESPONDING", e);
}
// Log.e(LOG_TAG, "CONNECTION ERROR FUNDAMO SERVER NOT RESPONDING", e);
return xmlRespone;
}
`
AgAppHelperMethods isn't really an Activity. You've derived this class from Activity, but then you've created Singleton management methods (getInstance()) and you are instantiating it yourself. This is bad. Don't do this.
Normally Android controls the instantiation of activities. You don't ever create one yourself (with new).
It looks to me like AgAppHelperMethods just needs to be a regular Java class. It doesn't need to inherit from anything. Remove also the lifecycle methods like onCreate().
Now you will have a problem with the toast, because you need a context for that and AgAppHelperMethods isn't a Context. To solve that you can add Context as a parameter to AgAppXMLParser() like this:
public String[][] AgAppXMLParser(Context context, String parUrl) {
...
// Now you can use "context" to create your toast.
}
When you call AgAppXMLParser() from AgAppMenu just pass "this" as the context parameter.