i have to create simple login page where after entering username and password we click to submit button. when we click on submit button then it goes to server and check the username and other information if the info matches then it moves to next activity otherwise nothing will happen . below is my code . i dont know how to do after getting response from the server.
package com.example.dev_1.myapplication;
import android.app.DownloadManager;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.net.Uri
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.lang.ref.ReferenceQueue;
import java.net.HttpURLConnection;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.sql.Connection;
public class MainActivity extends AppCompatActivity {
Button button;
String connectionString, params;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText username = (EditText) findViewById(R.id.editText);
final EditText password = (EditText) findViewById(R.id.editText2);
Button button = (Button) findViewById(R.id.button1);
button.setOnClickListener((new View.OnClickListener() {
#Override
public void onClick(View v) {
if (v.getId() == R.id.button1) {
String userNameString = username.getText().toString();
String passwordString = password.getText().toString();
String url = "http://122.160.78.189:82/androidserver/LoginSalesPerson";
String params = null;
try {
params = "user=" + URLEncoder.encode(userNameString, "UTF-8") + "&password=" + URLEncoder.encode(passwordString, "UTF-8") + "&appVersion=1.26";
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
JSONArray dataJsonArr = null;
new Mytask().execute(url, params);
}
}
}));
}
private void checkLogin(String result) throws JSONException {
String url = "http://122.160.78.189:82/androidserver/LoginSalesPerson";
JSONArray user = null;
try{
// Creating new JSON Parser
///JSONParser jParser = new JSONParser();
// Getting JSON from URL
// JSONObject json = jParser.getJSONFromUrl(url);
if (result != null)
{
//JSONObject emp=(new JSONObject(url).getJSONObject("username"));
JSONObject emp = new JSONObject(result.toString());
String username=emp.getString("userName");
//String empspassword=emp.getString("password");
String str="username:"+username;
Intent intent = new Intent(MainActivity.this, Main2Activity.class);
intent.putExtra("username", str);
startActivity(intent);}
}catch (Exception e) {
e.printStackTrace();
}
}
// EditText usernameString = (EditText) findViewById(R.id.editText);
// String str = usernameString.getText().toString();
// if (sharedPreferences.equals(str)) {
// Intent intent = new Intent(MainActivity.this, Main2Activity.class);
// intent.putExtra("username", str);
//startActivity(intent);
// To retrieve value from shared preference in another activity
// sharedPreferences = getApplicationContext().getSharedPreferences(
// "sharedPrefName", 0);
// id = sharedPreferences.getString("key_name", "defaultvalue");
class Mytask extends AsyncTask<String, Void, String> {
// Runs in UI before background thread is called
#Override
protected void onPreExecute() {
setProgressBarVisibility(true);
// Do something like display a progress bar
}
// This is run in a background thread
#Override
protected String doInBackground(String... params) {
return getFromServer(params[0], params[1]);
}
// This runs in UI when background thread finishes
#Override
protected void onPostExecute(String result) {
try {
checkLogin(result);
} catch (JSONException e) {
e.printStackTrace();
}
}
public String getFromServer(String connectionString, String params) {
String response = "";
try {
// android.os.Debug.waitForDebugger();
URL url = new URL(connectionString);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setConnectTimeout(10 * 1000); //10 Seconds
con.setRequestMethod("POST");
con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
con.setRequestProperty("Content-Length", "" + Integer.toString(params.getBytes().length));
con.setRequestProperty("Content-Language", "en-US");
con.setUseCaches(false);
con.setDoInput(true);
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(params);
wr.flush();
wr.close();
InputStream is = con.getInputStream();
response = read(is);
} catch (Exception e) {
e.printStackTrace();
} finally {
return response;
}
}
private String read(InputStream in) {
BufferedReader reader;
StringBuilder response = new StringBuilder();
try {
reader = new BufferedReader(new InputStreamReader(in));
String line;
while ((line = reader.readLine()) != null) {
response.append(line);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
return response.toString();
}
}
}
}
Related
So whenever I Enter a city name in the EditText and press the button my app just crashes and does not show a toast
shows this error in logcat : used by: java.lang.NullPointerException: Can't toast on a thread that has not called Looper.prepare()
Does anyone know who to fix this error?
im using android studio
package com.example.whatstheweather;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Looper;
import android.util.Log;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONObject;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class MainActivity extends AppCompatActivity {
EditText editText;
TextView resultTextView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = findViewById(R.id.editTextTextPersonName);
resultTextView = findViewById(R.id.resultTextView);
}
public void getWeather(View view){
try {
DownloadTask task = new DownloadTask();
String encodedCityName = URLEncoder.encode(editText.getText().toString(), "UTF-8");
task.execute("http://openweathermap.org/data/2.5/weather?q=" + encodedCityName + "&APPID=9eebb30a9664baf113136d98e764ffb5");
InputMethodManager mgr = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
mgr.hideSoftInputFromWindow(editText.getWindowToken(), 0);
}catch (Exception e){
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Could not find weather :(",Toast.LENGTH_SHORT).show();
}
}
public class DownloadTask extends AsyncTask<String, Void, String >{
#Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream in = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(in);
int data = reader.read();
while(data != -1){
char current = (char) data;
result += current;
data = reader.read();
}
return result;
}catch(Exception e){
e.printStackTrace();;
Toast.makeText(getApplicationContext(),"Could not find weather :(",Toast.LENGTH_SHORT).show();
return null;
}
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
try {
JSONObject jsonObject = new JSONObject(s);
String weatherInfo = jsonObject.getString("weather");
JSONArray arr = new JSONArray(weatherInfo);
String message = "";
for (int i = 0; i< arr.length(); i++){
JSONObject jsonPart =arr.getJSONObject(i);
String main = jsonPart.getString("main");
String description = jsonPart.getString("description");
if (!main.equals("") && !description.equals("")) {
message += main + ": " + description + "\r\n";
}
}
if (!message.equals("")){
resultTextView.setText(message);
}else{
Toast.makeText(getApplicationContext(),"Could not find weather :(",Toast.LENGTH_SHORT).show();
}
}catch (Exception e){
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Could not find weather :(",Toast.LENGTH_SHORT).show();
}
}
}
}
try {
//add her code
} catch (java.text.ParseException e) {
runOnUiThread(new Runnable(){
public void run() {
Toast.makeText(getApplicationContext(),"Please key in
the correct input",
Toast.LENGTH_LONG).show();
}
});
e.printStackTrace();
return true; // attention here
}
Method in onCreate :
private void toastPublic(final String message){
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
public void run() {
Toast.makeText(getBaseContext(),""+message,
4 /*Toast.LENGTH_SHORT*/).show();
}});
}
Next : use in inside asyncTask or Thread
I am trying to send an image and some string values from android to a php script using HttpURLConnection. I have successfully done so with strings, but can't seem to get it right with the image. I am using Base64 (android.util.Base64) to convert my image to a string to send it. Now, I have a separate HttpParse.java file I use to send all my info to the server, and I think that is where the change needs to be made to allow the image, but I'm not sure, (I am newer to java/android development). I've researched several similar questions, but they aren't fully clicking for me for what I'm doing wrong. Also, I have tested that I am successfully converting the image to a string. Here is my code:
EDIT I got a little farther... After testing, I am getting the issue because the three variables I try to get with getArguments() are coming back as null... But, I can't figure out how to get them to come through successfully... I added the code for how I start my fragment and how I try to get my bundle
My fragment start:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_units);
Intent intent = getIntent();
LexaUser = intent.getStringExtra("UserName");
ReadOnly = intent.getStringExtra("ReadOnly");
Password = intent.getStringExtra("Password");
QA = intent.getStringExtra("QA");
SearchValue = intent.getStringExtra("SearchInput");
bottomNavigation = (BottomNavigationView)findViewById(R.id.bottom_navigation);
bottomNavigation.inflateMenu(R.menu.bottom_menu);
fragmentManager = getSupportFragmentManager();
bottomNavigation.getMenu().getItem(0).setChecked(true);
UnitDetailsHeader = findViewById(R.id.UnitDetailsViewTitle);
UnitDetailsHeader.setText(SearchValue);
UnitSizeText = findViewById(R.id.UnitSize);
UnitStatusText = findViewById(R.id.UnitStatus);
if (SearchValue.contains("-")) {
getUnitDetails(SearchValue, LexaUser);
} else {
getSiblings();
}
bottomNavigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
int id = item.getItemId();
switch (id){
case R.id.action_search:
fragment = new NewUnitStatusFragment();
break;
case R.id.action_cart:
fragment = new PendingUnitStatusFragment();
break;
case R.id.action_hot_deals:
fragment = new FinalUnitStatusFragment();
break;
case R.id.action_siblings:
fragment = new SiblingUnitFragment();
break;
}
Bundle connBundle = new Bundle();
connBundle.putString("SearchValue", SearchValue);
connBundle.putString("LexaUser", LexaUser);
connBundle.putString("Password", Password);
connBundle.putString("QA", QA);
fragment.setArguments(connBundle);
final FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_container, fragment).commit();
return true;
}
});
}
And where I try to get my arguments: (I originally had in onCreateView but then tried to move it to onCreate. But the behavior was the same)
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
SearchValue = getArguments().getString("SearchValue");
LexaUser = getArguments().getString("LexaUser");
Password = getArguments().getString("Password");
}
}
My fragment where I get the image and send my data:
package [my_package];
import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.SpinnerAdapter;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import android.util.Base64;
import java.util.HashMap;
import static android.app.Activity.RESULT_OK;
public class NewUnitStatusFragment extends Fragment {
Context newUnitStatusContext;
Activity newUnitStatusActivity;
Intent cameraIntent;
ProgressDialog progressDialog;
String ReadOnly;
String LexaUser;
String Password;
String SearchValue;
String finalResultNewUnitStatus;
String HttpURLNewUnitStatus = "https://[path/to/file]/insertNewUnitStatus.php";
HashMap<String, String> hashMapNewUnitStatus = new HashMap<>();
HttpParse httpParse = new HttpParse();
Spinner statusSpinner;
Spinner generalCauseSpinner;
EditText newUSComment;
Button addPhotoBtn;
ImageView newUnitStatusImage;
Button addNewUnitStatus;
String newUnitStatus;
String generalCause;
String newUnitStatusComment;
String newUnitStatusPhoto;
String message;
private static final int PICK_FROM_GALLERY = 1;
public NewUnitStatusFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_newunitstatus, container, false);
newUnitStatusContext = getContext();
newUnitStatusActivity = getActivity();
statusSpinner = view.findViewById(R.id.Status);
generalCauseSpinner = view.findViewById(R.id.GeneralCause);
newUSComment = view.findViewById(R.id.NewComment);
newUnitStatusImage = view.findViewById(R.id.AddPhoto);
addPhotoBtn = view.findViewById(R.id.AddPhotosLabel);
addNewUnitStatus = view.findViewById(R.id.addBtnNewUnitStatus);
ArrayAdapter<CharSequence> statusSpinnerAdapter = ArrayAdapter.createFromResource(newUnitStatusContext,
R.array.new_unit_status_array, android.R.layout.simple_spinner_item);
statusSpinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
statusSpinner.setAdapter(statusSpinnerAdapter);
newUnitStatus = statusSpinner.getSelectedItem().toString();
ArrayAdapter<CharSequence> generalCauseSpinnerAdapter = ArrayAdapter.createFromResource(newUnitStatusContext,
R.array.status_general_cause_array, android.R.layout.simple_spinner_item);
generalCauseSpinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
generalCauseSpinner.setAdapter(generalCauseSpinnerAdapter);
generalCause = generalCauseSpinner.getSelectedItem().toString();
addPhotoBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startGallery();
}
});
// Set a click listener for the text view
addNewUnitStatus.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
newUnitStatus = statusSpinner.toString();
generalCause = generalCauseSpinner.toString();
newUnitStatusComment = newUSComment.toString();
if (getArguments() != null) {
SearchValue = getArguments().getString("SearchValue");
LexaUser = getArguments().getString("LexaUser");
Password = getArguments().getString("Password");
}
addNewUnitStatus(SearchValue, newUnitStatus, generalCause, newUnitStatusComment, newUnitStatusPhoto, LexaUser, Password);
}
});
return view;
}
private void startGallery() {
cameraIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
cameraIntent.setType("image/*");
cameraIntent.setAction(Intent.ACTION_GET_CONTENT);
if (cameraIntent.resolveActivity(getActivity().getPackageManager()) != null) {
startActivityForResult(cameraIntent, 1000);
} else {
Toast.makeText(newUnitStatusContext, "Error: " + cameraIntent + " - cameraIntent.resolveActivity(getActivity().getPackageManager()) = null", Toast.LENGTH_LONG).show();
}
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
//super method removed
if (resultCode == RESULT_OK) {
if (requestCode == 1000) {
Uri returnUri = data.getData();
try {
Bitmap bitmapImage = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), returnUri);
newUnitStatusImage.setImageBitmap(bitmapImage);
newUnitStatusImage.buildDrawingCache();
Bitmap bm = newUnitStatusImage.getDrawingCache();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] b = baos.toByteArray();
newUnitStatusPhoto = Base64.encodeToString(b, Base64.DEFAULT);
} catch (IOException ioEx) {
ioEx.printStackTrace();
Toast.makeText(newUnitStatusContext, "ioEx Error: " + ioEx, Toast.LENGTH_LONG).show();
}
} else {
Toast.makeText(newUnitStatusContext, "Error: " + requestCode, Toast.LENGTH_LONG).show();
}
} else {
Toast.makeText(newUnitStatusContext, "Error: " + resultCode, Toast.LENGTH_LONG).show();
}
}
public void addNewUnitStatus(String searchInput, String newUnitStatus, String generalCause, String newUnitStatusComment, String newUnitStatusPhoto, String lexaUser, String password) {
class NewUnitStatusClass extends AsyncTask<String,Void,String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = ProgressDialog.show(newUnitStatusContext, "Loading Data", null, true, true);
}
#Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
if (httpResponseMsg != null) {
try {
JSONObject object = new JSONObject(httpResponseMsg);
message = object.getString("message");
Toast.makeText(newUnitStatusContext, httpResponseMsg, Toast.LENGTH_LONG).show();
} catch (JSONException e) {
Log.e("JSONException", "Error: " + e.toString());
Toast.makeText(newUnitStatusContext, "Error: " + e.toString(), Toast.LENGTH_LONG).show();
} // catch (JSONException e)
progressDialog.dismiss();
} else {
progressDialog.dismiss();
Toast.makeText(newUnitStatusContext, "HttpResponseMsg is null.", Toast.LENGTH_LONG).show();
}
}
#Override
protected String doInBackground(String... params) {
hashMapNewUnitStatus.put("searchinput", params[0]);
hashMapNewUnitStatus.put("newUnitStatus", params[1]);
hashMapNewUnitStatus.put("generalCause", params[2]);
hashMapNewUnitStatus.put("newUnitStatusComment", params[3]);
hashMapNewUnitStatus.put("newUnitStatusPhoto", params[4]);
hashMapNewUnitStatus.put("lexauser", params[5]);
hashMapNewUnitStatus.put("password", params[6]);
finalResultNewUnitStatus = httpParse.postRequest(hashMapNewUnitStatus, HttpURLNewUnitStatus);
return finalResultNewUnitStatus;
}
}
NewUnitStatusClass newUnitStatusClass = new NewUnitStatusClass();
newUnitStatusClass.execute(searchInput, newUnitStatus, generalCause, newUnitStatusComment, newUnitStatusPhoto, lexaUser, password);
}
}
And my code to do that actuall HttpURLConnection: HttpParse.java
package [my_package];
import android.app.ListActivity;
import android.widget.ArrayAdapter;
import org.json.JSONArray;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
public class HttpParse extends ListActivity {
String FinalHttpData = "";
String Result;
BufferedWriter bufferedWriter;
OutputStream outputStream;
BufferedReader bufferedReader;
StringBuilder stringBuilder = new StringBuilder();
URL url;
public String postRequest(HashMap<String, String> Data, String HttpUrlHolder) {
try {
url = new URL(HttpUrlHolder);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setReadTimeout(14000);
httpURLConnection.setConnectTimeout(14000);
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoInput(true);
httpURLConnection.setDoOutput(true);
outputStream = httpURLConnection.getOutputStream();
bufferedWriter = new BufferedWriter(
new OutputStreamWriter(outputStream, "UTF-8"));
bufferedWriter.write(FinalDataParse(Data));
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
if (httpURLConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
bufferedReader = new BufferedReader(
new InputStreamReader(
httpURLConnection.getInputStream()
)
);
FinalHttpData = bufferedReader.readLine();
}
else {
FinalHttpData = "Something Went Wrong";
}
} catch (Exception e) {
e.printStackTrace();
}
return FinalHttpData;
}
public String FinalDataParse(HashMap<String,String> hashMap2) throws UnsupportedEncodingException {
for(Map.Entry<String,String> map_entry : hashMap2.entrySet()){
stringBuilder.append("&");
stringBuilder.append(URLEncoder.encode(map_entry.getKey(), "UTF-8"));
stringBuilder.append("=");
stringBuilder.append(URLEncoder.encode(map_entry.getValue(), "UTF-8"));
}
Result = stringBuilder.toString();
return Result ;
}
}
All help is appreciated! Thank you!
P.S. my app shows the following error:
W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
This then leads to this:
E/JSONException: Error: org.json.JSONException: End of input at character 0 of
I'm relatively new to Android app development and wonder what I'm doing wrong. I have an AsyncTask that connects to my web server with username and password and returns the user dataset as json object. Unfortunately I can't get the json string, because onPostExecute() in my AsyncHttpReading class doesn't seem to get called. Why?
MainActivity.java
package com.alphavoice.sampleproject;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import android.app.Activity;
import android.content.SharedPreferences;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import org.json.JSONException;
import org.json.JSONObject;
import com.alphavoice.sampleproject.community.user.User;
import com.alphavoice.sampleproject.util.HttpReader;
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SharedPreferences appPrefs = PreferenceManager.getDefaultSharedPreferences(this);
boolean isLoggedIn = (appPrefs.getInt("userId", 0) != 0) ? true : false;
if (isLoggedIn) {
renderCommunityView();
}
else {
setContentView(R.layout.activity_main);
final Button btnLogin = (Button) findViewById(R.id.btn_login);
final EditText etUsername = (EditText) findViewById(R.id.et_username);
final EditText etPassword = (EditText) findViewById(R.id.et_password);
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String username = etUsername.getText().toString();
String password = etPassword.getText().toString();
String loginUrl = "http://example.com/websrv/get_user.php?username=" + username + "&password=" + password;
AsyncHttpReading httpReading = new AsyncHttpReading();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
int corePoolSize = 60;
int maximumPoolSize = 80;
int keepAliveTime = 10;
BlockingQueue<Runnable> workQueue = new LinkedBlockingQueue<Runnable>(maximumPoolSize);
Executor threadPoolExecutor = new ThreadPoolExecutor(corePoolSize, maximumPoolSize, keepAliveTime, TimeUnit.SECONDS, workQueue);
// httpReading.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, loginUrl);
httpReading.executeOnExecutor(threadPoolExecutor, loginUrl);
}
else {
httpReading.execute(loginUrl);
}
if (httpReading.getLoggedInUser() != null) {
// renderCommunityView();
btnLogin.setBackgroundColor(Color.GREEN);
}
else {
// wrong combination of username & password => try again
etUsername.setBackgroundColor(Color.rgb(255, 204, 204));
etPassword.setBackgroundColor(Color.rgb(255, 204, 204));
}
}
});
}
}
private void renderCommunityView() {
setContentView(R.layout.activity_community);
}
private class AsyncHttpReading extends AsyncTask<String, Void, String> {
private String response = "";
private User loggedInUser = null;
public AsyncHttpReading() { }
public String getResponse() {
return response;
}
public User getLoggedInUser() {
return loggedInUser;
}
#Override
protected String doInBackground(String... urls) {
HttpReader httpReader = new HttpReader(urls[0]);
response = httpReader.getResponse();
return response;
}
#Override
protected void onPostExecute(String response) {
try {
JSONObject userData = new JSONObject(this.getResponse()).getJSONObject("0");
if (userData != null) {
loggedInUser = new User(userData);
}
} catch (JSONException e) {
Log.e("SAMPLEPROJECT", "Could not parse json data!");
}
}
}
}
HttpReader.java
package com.alphavoice.sampleproject.util;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import android.util.Log;
public class HttpReader {
private String url = "";
public HttpReader(String url) {
this.url = url;
}
public String getURL() {
return url;
}
public String getResponse() {
URL urlObj = null;
HttpURLConnection connection = null;
// http request
try {
urlObj = new URL(url);
connection = (HttpURLConnection) urlObj.openConnection();
connection.setReadTimeout(10000);
connection.setConnectTimeout(15000);
connection.setRequestMethod("POST");
connection.setDoInput(true);
connection.setDoOutput(true);
} catch (Exception e) {
Log.e("SAMPLEPROJECT", "Could not connect to web server!");
}
// read stream
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(urlObj.openStream()));
StringBuffer buffer = new StringBuffer();
char[] chars = new char[1024];
int read = 0;
while ((read = reader.read(chars)) != -1) {
buffer.append(chars, 0, read);
}
reader.close();
return buffer.toString();
} catch (IOException e) {
Log.e("SAMPLEPROJECT", "Could not open stream!");
}
return null;
}
}
User.java
package com.alphavoice.sampleproject.community.user;
import org.json.JSONObject;
public class User {
public User(JSONObject dataset) {
}
}
i am just a beginner in developing android applications, i wanted to connect my application to a server so i could get data from MySQL. so i tried to make login part first but i have some problems. my code doesn't work for reading JSON.
my codes are as below:
LoginActivity(MainActivity) :
package ir.naserpour.sportclub;
import android.content.Context;
import android.graphics.Typeface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.UnsupportedEncodingException;
import uk.co.chrisjenx.calligraphy.CalligraphyContextWrapper;
public class LoginActivity extends AppCompatActivity {
String link;
String response;
//get values
String username,password;
#Override
protected void attachBaseContext (Context newBase){
super.attachBaseContext(CalligraphyContextWrapper.wrap(newBase));
}
#Override
protected void onCreate (Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
//define things
TextView menu = (TextView) findViewById(R.id.menu);
final EditText login_username = (EditText) findViewById(R.id.login_username);
final EditText login_password = (EditText) findViewById(R.id.login_password);
Button login_login = (Button) findViewById(R.id.login_login);
Button login_register = (Button)findViewById(R.id.login_register);
CheckBox rememberme = (CheckBox)findViewById(R.id.login_remeberme);
//set icon type face
Typeface fonticon = Typeface.createFromAsset(getAssets(), "fonts/icon.ttf");
menu.setTypeface(fonticon);
login_login.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
username = login_username.getText().toString();
password = login_password.getText().toString();
//check values
if (username.length() <1 || password.length() < 1) {
Toast.makeText(getApplicationContext(), "fields cannot be empty", Toast.LENGTH_SHORT).show();
} else {
//generate link
link = "http://localhost:8080/login.php?username="+username+"&password="+password;
login();
if(response=="true"){
Toast.makeText(getApplicationContext(), "true", Toast.LENGTH_SHORT).show();
}else if(response=="false"){
Toast.makeText(getApplicationContext(), "false", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(getApplicationContext(), "response", Toast.LENGTH_SHORT).show();
}
}
}
});
}
#Override
protected void onPause () {
super.onPause();
finish();
}
public String login() {
new JSONParse().execute();
return response;
}
public class JSONParse extends AsyncTask<String, String, JSONObject> {
#Override
public void onPreExecute() {
super.onPreExecute();
Toast.makeText(getApplicationContext(),"getting data ...",Toast.LENGTH_SHORT).show();
}
#Override
public JSONObject doInBackground(String... args) {
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject json = jParser.getJSONFromUrl(link);
return json;
}
#Override
public void onPostExecute(JSONObject json) {
try {
JSONArray result = json.getJSONArray("result");
JSONObject c = result.getJSONObject(0);
try {
String res = new String(c.getString("response").getBytes("ISO-8859-1"), "UTF-8");
response = res;
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}
JSONParser.java:
package ir.naserpour.sportclub;
import android.util.Log;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
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.UnsupportedEncodingException;
/**
* Created by Mohammad Naserpour on 9/22/2016.
*/
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httppost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
and also my login.php script:
<?php
define("HOST","localhost");
define("USERNAME","root");
define("PASSWORD","");
define("NAME","users");
$con = mysqli_connect(HOST,USERNAME,PASSWORD,NAME);
$username = $_GET["username"];
$password = $_GET["password"];
$sql = "SELECT * FROM userinfo WHERE username ='$username' AND password='$password'";
$check = mysqli_fetch_array(mysqli_query($con,$sql));
if(isset($check)){
echo '{"result":[{"response":"true"}]}';
}else{
echo '{"result":[{"response":"false"}]}';
}
mysqli_close($con);
?>
i would be so happy if i find out the problem. thank you.
see this tutorial :
its a full tutorial about login process using google volley
First : On device side, Use volley, its simple and easy to use
Second : On server, what is {"result":[{"response":"true"}]}
any problem with {"result":true} ??
Last but not the least : Did you use JSON before or this code is trial and error copy paste from some tutorials?
I am trying to start an activity "Display" which is supposed to start only after the user is authenticated (the usernames and passwords are stored in phpmyadmin database)
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class PatLogin extends Activity {
EditText a,b;
String login_name,login_pass;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.pat_login);
}
public void patbuttonClick(View v) {
if (v.getId() == R.id.patlogin) {
a = (EditText) findViewById(R.id.TFpusername);
b = (EditText) findViewById(R.id.TFppassword);
login_name = a.getText().toString();
login_pass = b.getText().toString();
String method = "login";
BackgroundTask backgroundTask = new BackgroundTask(this);
backgroundTask.execute(method,login_name,login_pass);
//If possible I would like to call the "Display" activity from here but only when the correct username and password is entered.
//If it's not possible to call from here then I would like to know how to call "Display" activity from "BackgrounTask.java".
}
}
}
The BackgroundTask.java is used to authenticate the user (check if the username and password match) through the phpmyadmin database.
import android.app.AlertDialog;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
public class BackgroundTask extends AsyncTask<String,Void,String> {
AlertDialog alertDialog;
Context ctx;
BackgroundTask(Context ctx)
{
this.ctx =ctx;
}
int flag=0;
#Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(ctx).create();
alertDialog.setTitle("Login Information....");
}
#Override
protected String doInBackground(String... params) {
String login_url = "http://10.0.2.2/mobidoc/login.php";
String method = params[0];
if(method.equals("login"))
{
String login_name = params[1];
String login_pass = params[2];
try {
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
String data = URLEncoder.encode("login_name","UTF-8")+"="+URLEncoder.encode(login_name,"UTF-8")+"&"+
URLEncoder.encode("login_pass","UTF-8")+"="+URLEncoder.encode(login_pass,"UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
String response = "";
String line = "";
while ((line = bufferedReader.readLine())!=null)
{
response+= line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return response;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
#Override
protected void onPostExecute(String result) {
if(result.equals("Registration Success..."))
{
Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
}
else
{
alertDialog.setMessage(result);
alertDialog.show();
//When I use the following 2 lines of code, It calls the Display activity even if the wrong password is entered. I need a certain condition to be applied.
Intent myIntent = new Intent(ctx, Display.class);
ctx.startActivity(myIntent);
}
}
}
So what I want to do is call an activity named "Display". This activity should be called only when the correct username and password is entered.
I am attaching the php file too, just for reference.
<?php
require "init.php";
$username = $_POST["login_name"];
$password = $_POST["login_pass"];
$password = md5($password);
$sql_query = "select name from pat_info where username like '$username' and password like '$password';";
$result = mysqli_query($con,$sql_query);
if(mysqli_num_rows($result)>0)
{
$row = mysqli_fetch_assoc($result);
$name = $row["name"];
echo "Login Success... Welcome ".$name;}
else{
echo "Login Failed...Try Again.";
}
Ok I got the solution to it. I had to compare the echo of the php file and compare it with "res" which stores the value of "result". The modified "BackgroundTask.java" is below:
import android.app.AlertDialog;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
public class BackgroundTask extends AsyncTask<String,Void,String> {
AlertDialog alertDialog;
Context ctx;
String res;
BackgroundTask(Context ctx)
{
this.ctx =ctx;
}
int flag=0;
#Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(ctx).create();
alertDialog.setTitle("Login Information....");
}
#Override
protected String doInBackground(String... params) {
String login_url = "http://10.0.2.2/mobidoc/login.php";
String method = params[0];
if(method.equals("login"))
{
String login_name = params[1];
String login_pass = params[2];
try {
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
String data = URLEncoder.encode("login_name","UTF-8")+"="+URLEncoder.encode(login_name,"UTF-8")+"&"+
URLEncoder.encode("login_pass","UTF-8")+"="+URLEncoder.encode(login_pass,"UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
String response = "";
String line = "";
while ((line = bufferedReader.readLine())!=null)
{
response+= line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
//I stored the response in the following String variable (res)
res = response;
return response;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
#Override
protected void onPostExecute(String result) {
if(result.equals("Registration Success..."))
{
Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
}
else if(res.equals("Login Failed...Try Again."))
{
alertDialog.setMessage(result);
alertDialog.show();
}
else
{
alertDialog.setMessage(result);
alertDialog.show();
Intent myIntent = new Intent(ctx, Display.class);
ctx.startActivity(myIntent);
}
}
}