I have a form having one edittext and an autocompleteview. And a button to search things based on this form. In this form I can either give value in edittext and autocompleteview may be empty and vice versa. On this basis I have passed value of these view to another activity where I made a webservice call and then fetch result.
This is activity where these view are presents:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_patient_section);
getSupportActionBar().hide();
searchByNameEditText = (EditText) findViewById(R.id.searchByNameEditText);
searchByAddressEditText = (EditText) findViewById(R.id.searchByAddressEditText);
searchButton = (Button) findViewById(R.id.searchButton);
autoCompleteTextView = (AutoCompleteTextView) findViewById(R.id.selectStateSpinner);
ArrayAdapter<String> adapter = new ArrayAdapter<>(this,
android.R.layout.simple_dropdown_item_1line,
getResources().getStringArray(R.array.state_arrays));
autoCompleteTextView.setAdapter(adapter);
patientUtilityButton = (Button) findViewById(R.id.patientUtilityButton);
patientUtilityButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
PopupMenu popupMenu = new PopupMenu(PatientSectionActivity.this, patientUtilityButton);
popupMenu.getMenuInflater().inflate(R.menu.patient_utility_button_popmenu, popupMenu.getMenu());
popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
#Override
public boolean onMenuItemClick(MenuItem item) {
String patientUtilityMenuItem = item.toString();
patientUtilityButton.setText(patientUtilityMenuItem);
return true;
}
});
popupMenu.show();
}
});
autoCompleteTextView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectedStateValue = (String) parent.getItemAtPosition(position);
}
});
doctorName = searchByNameEditText.getText().toString();
// Search Button
searchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!selectedStateValue.equals(" ") || doctorName.equals(" ")){
Intent intent = new Intent(PatientSectionActivity.this, DoctorNameActivity.class);
intent.putExtra("State Name", selectedStateValue);
startActivity(intent);
} else if (!doctorName.equals(" ") || selectedStateValue.equals(" ")){
Intent intent = new Intent(PatientSectionActivity.this, DoctorNameActivity.class);
intent.putExtra("Name", doctorName);
startActivity(intent);
}
}
});
}
And in other activity, I get these extras from intent and make webservice call in AsyncTask but my app is crashing. Please any one help me as I am new in android.
This is my other activity
import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
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.net.HttpURLConnection;
import java.net.URL;
public class DoctorNameActivity extends ActionBarActivity {
ArrayAdapter<String> doctorAdapter;
ListView listView;
ProgressBar progressBar;
String doctorName;
String selectedStateValue;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_doctor_name);
progressBar = (ProgressBar) findViewById(R.id.progress);
listView = (ListView) findViewById(R.id.listView);
Intent intent = getIntent();
selectedStateValue = intent.getStringExtra("State Name");
doctorName = intent.getStringExtra("Name");
if (!selectedStateValue.equals(" ") || doctorName.equals(" ")){
FetchDoctorName fetchDoctorName = new FetchDoctorName();
fetchDoctorName.execute(selectedStateValue);
}else if (!doctorName.equals(" ") || selectedStateValue.equals(" ")){
FetchDoctorName fetchDoctorName = new FetchDoctorName();
fetchDoctorName.execute(doctorName);
}
}
private class FetchDoctorName extends AsyncTask<String, Void, String[]>{
private final String LOG_TAG = FetchDoctorName.class.getSimpleName();
public String[] parseDoctorName(String jsonString) throws JSONException{
final String DOCTOR_NAME_ARRAY = "name";
JSONObject object = new JSONObject(jsonString);
JSONArray array = object.getJSONArray(DOCTOR_NAME_ARRAY);
String[] doctorNamesResult = new String[array.length()];
for (int i = 0 ; i < array.length(); i++){
String doctorName = array.getString(i);
Log.v(LOG_TAG, doctorName);
doctorNamesResult[i] = doctorName;
}
return doctorNamesResult;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
progressBar.setVisibility(ProgressBar.VISIBLE);
}
#Override
protected String[] doInBackground(String... params) {
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String doctorJsonString = null;
try {
final String BASE_URL = "http://mycityortho.com/display_result.php";
final String NAME_PARAM = "name";
final String STATE_PARAM = "state";
URL url = null;
if (params[0].equals(doctorName)){
Uri uri = Uri.parse(BASE_URL).buildUpon()
.appendQueryParameter(NAME_PARAM, params[0])
.build();
url = new URL(uri.toString());
Log.v(LOG_TAG, url.toString());
}else if (params[0].equals(selectedStateValue)){
Uri uri = Uri.parse(BASE_URL).buildUpon()
.appendQueryParameter(STATE_PARAM, params[0])
.build();
url = new URL(uri.toString());
Log.v(LOG_TAG, url.toString());
}
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
doctorJsonString = buffer.toString();
Log.v(LOG_TAG, doctorJsonString);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attemping
// to parse it.
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
try {
return parseDoctorName(doctorJsonString);
}catch (JSONException e){
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String[] result) {
progressBar.setVisibility(ProgressBar.GONE);
if (result != null){
doctorAdapter = new ArrayAdapter<>(DoctorNameActivity.this, android.R.layout.simple_list_item_1, result);
listView.setAdapter(doctorAdapter);
}
}
}
As per your code you are sending only one value in intent that is "State Name" or "Name" but in other activity you are trying to receive both value, that why you get null pointer exception.
So use the following code to solve this error.
searchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!selectedStateValue.equals(" ") || doctorName.equals(" ")){
Intent intent = new Intent(PatientSectionActivity.this, DoctorNameActivity.class);
intent.putExtra("State Name", selectedStateValue);
intent.putExtra("Name", " ");
startActivity(intent);
} else if (!doctorName.equals(" ") || selectedStateValue.equals(" ")){
Intent intent = new Intent(PatientSectionActivity.this, DoctorNameActivity.class);
intent.putExtra("State Name", " ");
intent.putExtra("Name", doctorName);
startActivity(intent);
}
}
});
Related
NOTE :
First of all before writing any thing. this is not a duplicate because if it is then why I will post this here. I didn't find any of the stackoverflow similar questions' answers helpful to me at all for 2 days straight.
THE PROBLEM :
I have an activity that takes two fields of data and then go to the next activity where it has a view pager and the activity opens 2 fragments the posts and the profile. the problem here is that when I go back to the first activity to input different data and go to the fragments the listview shows duplicate data.
I tried every possible solution but none works.
I tried to clear adapter.
I tried to pass empty adapter.
I tried more things in the life cycle of the fragment but nothing.
so please I need help. thanks in advance.
package psychrating.psychrating;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.Spinner;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Created by Ahmeed on 8/7/2017.
*/
public class PostsFragment extends Fragment {
static ListView posts_list;
Spinner list_order;
SearchView search;
String category, date, activity;
boolean get_data;
public static ArrayList<String> data = null;
static Context c;
transient ViewHolder holder;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
data = null;
activity = getArguments().getString("activity");
category = getArguments().getString("category");
date = getArguments().getString("date");
if (activity == "main") {
// get_data = true;
}else {
// get_data = true;
}
View view = inflater.inflate(R.layout.post_tab, container, false);
init(view);
posts_list.clearChoices();
if (searchResultses != null) {
searchResultses.clear();
searchResultses = null;
}
return view;
}
private void init(View view) {
posts_list = (ListView) view.findViewById(R.id.posts_list);
list_order = (Spinner) view.findViewById(R.id.list_order);
search = (SearchView) view.findViewById(R.id.search);
posts_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
holder = (ViewHolder) view.getTag();
Temp temp = new Temp();
temp.name = holder.name.getText().toString();
temp.highest = holder.highest.getText().toString();
temp.dname = holder.dname.getText().toString();
temp.date = holder.date.getText().toString();
temp.category = holder.category;
temp.sdesc = holder.sdesc;
temp.ddesc = holder.ddesc;
Intent i = new Intent(c, ProfileActivity.class);
i.putExtra("holder", temp);
startActivity(i);
}
});
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
c = context;
}
#Override
public void onResume() {
super.onResume();
searchResultses = new ArrayList<>();
new Server(this.getActivity(), "posts").execute(category, date);
}
public static final String TAG ="ahmed";
static void removeCommas() {
StringBuilder word = new StringBuilder();
for (int i = 0; i < data.size(); i++) {
for (int j = 0; j < data.get(i).length(); j++) {
char c = data.get(i).charAt(j);
if (c != ',') {
word.append(c);
}else {
words.add(word.toString());
word.delete(0, word.length());
}
}
}
}
#Override
public void onPause() {
super.onPause();
searchResultses = null;
adapter = null;
}
#Override
public void onDestroyView() {
super.onDestroyView();
}
static void addToClass() {
SearchResults s;
int offset = 0;
for (int j = 0; j < words.size(); j += 8) {
Log.d(TAG, String.valueOf(words.size()));
s = new SearchResults();
for (int i = 0; i < 8; i++) {
offset = 1;
s.add(words.get(i * offset));
}
offset += 1;
s.init();
searchResultses.add(s);
}
}
static ArrayList<SearchResults> searchResultses = null;
static ArrayList<String> words = new ArrayList<>();
static MyCustomBaseAdapter adapter = null;
public static void fillList() {
removeCommas();
addToClass();
ArrayList<SearchResults> empty = new ArrayList<>();
adapter = new MyCustomBaseAdapter(c, empty);
adapter = new MyCustomBaseAdapter(c, searchResultses);
posts_list.setAdapter(adapter);
}
}
NOTE:
the fillList is a func that is being called by the asynctask when it finished retrieving data . which use the data variable and remove commas from data and add words to searchResult class
package psychrating.psychrating;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.io.Serializable;
import java.util.ArrayList;
/**
* Created by Ahmeed on 8/10/2017.
*/
public class MyCustomBaseAdapter extends BaseAdapter {
private static ArrayList<SearchResults> searchArrayList = null;
private LayoutInflater mInflater;
public MyCustomBaseAdapter(Context context, ArrayList<SearchResults> results) {
super();
searchArrayList = results;
mInflater = LayoutInflater.from(context);
}
public int getCount() {
return searchArrayList.size();
}
public Object getItem(int position) {
return searchArrayList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row, parent, false);
holder = new ViewHolder(convertView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.name.setText(searchArrayList.get(position).getName());
holder.highest.setText(searchArrayList.get(position).getHighest());
holder.dname.setText(searchArrayList.get(position).getDName());
holder.date.setText(searchArrayList.get(position).getDate());
holder.category = searchArrayList.get(position).getCategory();
holder.sdesc = searchArrayList.get(position).getSdesc();
holder.ddesc = searchArrayList.get(position).getDdesc();
convertView.setTag(holder);
return convertView;
}
}
Server class
package psychrating.psychrating;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.support.v7.app.AlertDialog;
import android.util.Log;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
/**
* Created by Ahmeed on 8/6/2017.
*/
public class Server extends AsyncTask<String, String, String> {
private Context context;
private ProgressDialog progressDialog;
private AlertDialog.Builder builder;
private String type;
private static ArrayList<String> data = null;
Server(Context context, String type) {
this.context = context;
this.type = type;
}
private void createPreDialog(String message) {
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(message);
progressDialog.setCancelable(false);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
progressDialog.create();
}
progressDialog.show();
}
#Override
protected void onPreExecute() {
super.onPreExecute();
createPreDialog("hold on");
}
#Override
protected String doInBackground(String... params) {
switch (type) {
case "login":
String personName = params[0];
String personEmail = params[1];
String id = params[2];
//
OutputStreamWriter outputStreamWriter = null;
BufferedWriter writer = null;
BufferedReader bufferedReader = null;
HttpURLConnection connection = null;
String line;
String result = null;
try {
URL url = new URL("http://192.168.1.64/blabla/sign_in.php");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setConnectTimeout(8000);
outputStreamWriter = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
writer = new BufferedWriter(outputStreamWriter);
String parameters = "name=" + personName + "&email=" + personEmail + "&id=" + id;
writer.write(parameters);
writer.flush();
if (connection.getResponseCode() == 200) {
bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
while ((line = bufferedReader.readLine()) != null) {
result = line;
}
} else {
result = "Server Error";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (outputStreamWriter != null) {
outputStreamWriter.close();
}
if (connection != null) {
connection.disconnect();
}
if (bufferedReader != null) {
bufferedReader.close();
}
if (writer != null) {
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
case "posts":
String category = params[0];
String date = params[1];
//
OutputStreamWriter outputStreamWriter1 = null;
BufferedWriter writer1 = null;
BufferedReader bufferedReader1 = null;
HttpURLConnection connection1 = null;
String line1 = "";
String result1 = null;
try {
URL url1 = new URL("http://192.168.1.64/blabla/posts.php");
connection1 = (HttpURLConnection) url1.openConnection();
connection1.setRequestMethod("POST");
connection1.setDoOutput(true);
connection1.setDoInput(true);
connection1.setConnectTimeout(8000);
outputStreamWriter1 = new OutputStreamWriter(connection1.getOutputStream(), "UTF-8");
writer1 = new BufferedWriter(outputStreamWriter1);
String parameters1 = "category="+category+"&date="+date;
writer1.write(parameters1);
writer1.flush();
data = new ArrayList<>();
if (connection1.getResponseCode() == 200) {
bufferedReader1 = new BufferedReader(new InputStreamReader(connection1.getInputStream()));
while ((line1 = bufferedReader1.readLine()) != null) {
data.add(line1);
}
} else {
result1 = "Server Error";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (outputStreamWriter1 != null) {
outputStreamWriter1.close();
}
if (connection1 != null) {
connection1.disconnect();
}
if (bufferedReader1 != null) {
bufferedReader1.close();
}
if (writer1 != null) {
writer1.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result1;
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
progressDialog.dismiss();
switch (type) {
case "login":
switch (s) {
case "Connect Error":
createDialog(s);
break;
case "Done":
Toast.makeText(context, s, Toast.LENGTH_LONG).show();
MainActivity.updateUI(true);
break;
case "Already Exist":
MainActivity.updateUI(true);
break;
case "Server Error":
createDialog(s);
break;
}
break;
case "posts":
if (data != null) {
PostsFragment.data = data;
PostsFragment.fillList();
data = null;
}
}
}
private void createDialog(String message) {
builder = new AlertDialog.Builder(context);
builder.setTitle("Error");
builder.setMessage(message);
builder.setCancelable(false);
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
builder.create();
builder.show();
}
}
Your words in PostsFragment.java makes you element duplicate, In removeCommas() method first clears the words and then add the values to the words from data.
try this. searchResultses.clear(); at the start of addToClass()
static void addToClass() {
SearchResults s;
searchResultses.clear();
int offset = 0;
for (int j = 0; j < words.size(); j += 8) {
Log.d(TAG, String.valueOf(words.size()));
s = new SearchResults();
for (int i = 0; i < 8; i++) {
offset = 1;
s.add(words.get(i * offset));
}
offset += 1;
s.init();
searchResultses.add(s);
}
}
Aim: Building app on Google API to fetch the data about the books the user searches
Problem Explanation:
Whenever I hit the submit Button, my app crashes.
This is my first approach in making a network request app and I need guidance.
MainActivityClass
package com.example.vidit.books;
import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText query = (EditText) findViewById(R.id.query);
Button submit= (Button) findViewById(R.id.submit);
submit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent= new Intent(MainActivity.this,Request.class);
intent.putExtra ( "text", query.getText().toString() );
startActivity(intent);
}
});
}
}
Second Class
package com.example.vidit.books;
import android.content.Intent;
public class Request {
Intent i = getIntent();
String text = i.getStringExtra ("text");
public static final String LOG_TAG = Request.class.getSimpleName();
String APIURL="https://www.googleapis.com/books/v1/volumes?q= " + text;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_request);
}
public void UpdateUi(Book book)
{
BookAdapter bookAdapter = new BookAdapter(this,book);
ListView listView= (ListView) findViewById(R.id.listview_all);
}
private class BookAsyncTask extends AsyncTask<URL,Void,Book>
{
#Override
protected Book doInBackground(URL... urls) {
URL url = createUrl(APIURL);
String jsonResponse = "";
try {
jsonResponse = makeHttpRequest(url);
} catch (IOException e) {
// TODO Handle the IOException
}
final Book book = extractFeatureFromJson(jsonResponse);
return book;
}
/**
* Make an HTTP request to the given URL and return a String as the response.
*/
private String makeHttpRequest(URL url) throws IOException {
String jsonResponse = "";
HttpURLConnection urlConnection = null;
InputStream inputStream = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setReadTimeout(10000 /* milliseconds */);
urlConnection.setConnectTimeout(15000 /* milliseconds */);
urlConnection.connect();
if(urlConnection.getResponseCode()==200) {
inputStream = urlConnection.getInputStream();
jsonResponse = readFromStream(inputStream);
}
} catch (IOException e) {
// TODO: Handle the exception
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
// function must handle java.io.IOException here
inputStream.close();
}
}
return jsonResponse;
}
/**
* Convert the {#link InputStream} into a String which contains the
* whole JSON response from the server.
*/
private 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();
}
/**
* Returns new URL object from the given string URL.
*/
private URL createUrl(String stringUrl) {
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException exception) {
Log.e(LOG_TAG, "Error with creating URL", exception);
return null;
}
return url;
}
private Book extractFeatureFromJson(String bookJSON) {
try {
JSONObject baseJsonResponse = new JSONObject(bookJSON);
JSONArray items = baseJsonResponse.getJSONArray("items");
// If there are results in the features array
for(int i=0;i<10;i++)
{
JSONObject firstFeature = items.getJSONObject(i);
JSONArray author=firstFeature.getJSONArray("author");
for(int j=0;j<author.length();j++)
{
JSONObject authorFeature=author.getJSONObject(j);
}
String title = items.getString(Integer.parseInt("title"));
// Create a new {#link Event} object
return new Book(title,author);
}
} catch (JSONException e) {
Log.e(LOG_TAG, "Problem parsing the earthquake JSON results", e);
}
return null;
}
}
}
BookAdapter Class:
package com.example.vidit.books;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.List;
public class BookAdapter extends ArrayAdapter<Book> {
public BookAdapter(Activity context, Book book)
{
super(context,0, (List<Book>) book);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View listItemView = convertView;
if(listItemView == null) {
listItemView = LayoutInflater.from(getContext()).inflate(
R.layout.list_item, parent, false);
}
Book cbook=getItem(position);
TextView title = (TextView) listItemView.findViewById(R.id.title);
title.setText(cbook.getmTitle());
TextView author=(TextView) listItemView.findViewById(R.id.author);
author.setText((CharSequence) cbook.getmAuthor());
return listItemView;
}
}
Showing error in statement:
String text = i.getStringExtra ("text");
Need guidance
I don't know how your code gets compiled when you have overridden onCreate() in Request class and the Request class isn't extending Activity or AppCompatActivity.
Secondly, this line :
Intent i = getIntent();
String text = i.getStringExtra ("text");
should be inside the onCreate() method.
Showing error in statement : String text = i.getStringExtra ("text");
Request for Guidance
Well you need to get the data passed inside onCreate like below.
String APIURL;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_request);
Bundle bundle = getIntent().getExtras();
String text = bundle.getString("text");
APIURL="https://www.googleapis.com/books/v1/volumes?q= " + text;
}
And although you have the asyncTask class i can't see where exactly you execute the class. You need to do that inside onCreate as well.
Try moving this code to your onCreate method
Intent i = getIntent();
String text = i.getStringExtra ("text");
The intent extras is not available in the constructor for your Request class.
I am trying to update the data using swipeRefreshLayout, but every time I swipe down to refresh it is only circling but not refreshing.
Can you please help me how to fix it.
package com.reader.ashishyadav271.hackernewsreader;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteStatement;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.widget.SwipeRefreshLayout;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
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.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class MainActivity extends Activity {
SwipeRefreshLayout mSwipeRefreshLayout;
Map<Integer, String> articleURLs = new HashMap<>();
Map<Integer, String> articleTitles = new HashMap<>();
ArrayList<Integer> articleIds = new ArrayList<>();
SQLiteDatabase articlesDB;
ArrayList<String> titles = new ArrayList<>();
ArrayAdapter arrayAdapter;
ArrayList<String> urls = new ArrayList<>();
ArrayList<String> content = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.activity_main_swipe_refresh_layout);
mSwipeRefreshLayout.setColorSchemeResources(R.color.red, R.color.green, R.color.blue, R.color.yellow);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
refreshContent();
}
});
ListView listView = (ListView) findViewById(R.id.listView);
arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, titles);
listView.setAdapter(arrayAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i = new Intent(getApplicationContext(), Main2Activity.class);
i.putExtra("articleUrl", urls.get(position));
i.putExtra("content", content.get(position));
startActivity(i);
}
});
articlesDB = this.openOrCreateDatabase("Articles", MODE_PRIVATE, null);
articlesDB.execSQL("CREATE TABLE IF NOT EXISTS articles (id INTEGER PRIMARY KEY, articleId INTEGER, url VARCHAR, title VARCHAR, content VARCHAR)");
updateListView();
DownloadTask task = new DownloadTask();
try {
task.execute("https://hacker-news.firebaseio.com/v0/topstories.json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
}
}
private void refreshContent() {
arrayAdapter.notifyDataSetChanged();
titles.clear();
updateListView();
mSwipeRefreshLayout.setRefreshing(false);
}
public void updateListView() {
try {
Log.i("UI UPDATED", "DONE");
Cursor c = articlesDB.rawQuery("SELECT * FROM articles", null);
int contentIndex = c.getColumnIndex("content");
int urlIndex = c.getColumnIndex("url");
int titleIndex = c.getColumnIndex("title");
c.moveToFirst();
titles.clear();
urls.clear();
while (c != null) {
titles.add(c.getString(titleIndex));
urls.add(c.getString(urlIndex));
content.add(c.getString(contentIndex));
c.moveToNext();
}
arrayAdapter.notifyDataSetChanged();
}catch (Exception e) {
e.printStackTrace();
}
}
public class DownloadTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpURLConnection urlConnection;
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();
}
JSONArray jsonArray = new JSONArray(result);
articlesDB.execSQL("DELETE FROM articles");
for (int i = 0; i < 20; i++) {
String articleId = jsonArray.getString(i);
url = new URL("https://hacker-news.firebaseio.com/v0/item/" + articleId + ".json?print=pretty");
urlConnection = (HttpURLConnection) url.openConnection();
in = urlConnection.getInputStream();
reader = new InputStreamReader(in);
data = reader.read();
String articleInfo = "";
while (data != -1 ) {
char current = (char) data;
articleInfo += current;
data = reader.read();
}
JSONObject jsonObject = new JSONObject(articleInfo);
String articleTitle = jsonObject.getString("title");
String articleURL = jsonObject.getString("url");
String articleContent = "";
/*
url = new URL(articleURL);
urlConnection = (HttpURLConnection) url.openConnection();
in = urlConnection.getInputStream();
reader = new InputStreamReader(in);
data = reader.read();
while (data != -1 ) {
char current = (char) data;
articleInfo += current;
data = reader.read();
}
*/
articleIds.add(Integer.valueOf(articleId));
articleTitles.put(Integer.valueOf(articleId), articleTitle);
articleURLs.put(Integer.valueOf(articleId), articleURL);
String sql = "INSERT INTO articles (articleId, url, title, content) VALUES (? , ? , ? , ?)";
SQLiteStatement statement = articlesDB.compileStatement(sql);
statement.bindString(1, articleId);
statement.bindString(2, articleURL);
statement.bindString(3, articleTitle);
statement.bindString(4, articleContent);
statement.execute();
}
}catch (Exception e) {
e.printStackTrace();
}
return result;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
refreshContent();
}
}
}
It look like synchronism problem. I can see you load data from DownloadTask and put all of data to database. RefreshMethod query data from database.
I assume if DownloadTask do not finish yet, database isn't updated and RefreshMethod would get nothing from database. So, It is only circling but not refreshing.
To solve synchronism problem, the right application flow should be: Raise PullToRefresh Event -> execute DownloadTask -> Wait until DownloadTask finish, RefreshMethod query database for data.
Code looks like:
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
DownloadTask task = new DownloadTask();
try {
task.execute("https://hacker-news.firebaseio.com/v0/topstories.json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
}
}
});
I have a scenario in which I have a form with four fields. In which one field will take same input only 5 times. On entering in 6th times activity will not go to another activity on button click. Please somebody help me as I have spent so many hours.
Here is my code
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
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.net.HttpURLConnection;
import java.net.URL;
public class LoginFragment extends Fragment {
private EditText phone, emailId, doctorName, doctorUniqueNumber;
private Button submitButton;
private String code;
public LoginFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
phone = (EditText) rootView.findViewById(R.id.phoneNumber);
emailId = (EditText) rootView.findViewById(R.id.emailId);
doctorName = (EditText) rootView.findViewById(R.id.doctorName);
doctorUniqueNumber = (EditText) rootView.findViewById(R.id.doctorUniqueNumber);
submitButton = (Button) rootView.findViewById(R.id.button);
submitButton.setOnClickListener(click);
return rootView;
}
View.OnClickListener click = new View.OnClickListener() {
#Override
public void onClick(View v) {
if ((!phone.getText().toString().isEmpty()) && (!doctorName.getText().toString().isEmpty())
&& (!emailId.getText().toString().isEmpty()) && (!doctorUniqueNumber.getText().toString().isEmpty())){
AuthenticateDoctor doctor = new AuthenticateDoctor();
doctor.execute();
}
}
};
private void setPrefs(String key, int value){
SharedPreferences preferences = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt(key, value);
editor.apply();
}
private int getPrefs(String key, int defaultValue){
SharedPreferences preferences = getActivity().getPreferences(Context.MODE_PRIVATE);
return preferences.getInt(key, defaultValue);
}
private void setStringPrefs(String key, String value){
SharedPreferences preferences = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putString(key, value);
editor.apply();
}
private String getStringPrefs(String key, String defaultValue){
SharedPreferences preferences = getActivity().getPreferences(Context.MODE_PRIVATE);
return preferences.getString(key, defaultValue);
}
#Override
public void onDestroyView() {
super.onDestroyView();
}
private class AuthenticateDoctor extends AsyncTask<Void, Void, String>{
private final String LOG_TAG = AuthenticateDoctor.class.getSimpleName();
#Override
protected String doInBackground(Void... params) {
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String data;
try {
// Construct the URL for the OpenWeatherMap query
// Possible parameters are avaiable at OWM's forecast API page, at
// http://openweathermap.org/API#forecast
URL url = new URL("http://spirantcommunication.com/andriod/grl/show.php?" + "code=" +
doctorUniqueNumber.getText().toString());
// Create the request to OpenWeatherMap, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
data = buffer.toString();
Log.v("Data", data);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attemping
// to parse it.
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
return data;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
JSONObject object = new JSONObject(result);
JSONArray array = object.getJSONArray("Message");
code = array.getString(0);
Log.v("Code", code);
}catch (JSONException e){
e.printStackTrace();
}
if (code.equals("success")){
int numberOfTimes = getPrefs("Number of Times", 0);
if (numberOfTimes > 5){
Toast.makeText(getActivity(), "Exceed value", Toast.LENGTH_SHORT).show();
setStringPrefs("Doctor Unique Number", " ");
}else {
numberOfTimes++;
setPrefs("Number of Times", numberOfTimes);
setStringPrefs("Doctor Unique Number", doctorUniqueNumber.getText().toString());
Intent intent = new Intent(getActivity(), DoctorDashboardActivity.class);
startActivity(intent);
}
}else if (code.equals("Faliure")){
Toast.makeText(getActivity(), "This unique number is not present", Toast.LENGTH_SHORT).show();
}
}
}
}
First, you will have an int member in LoginFragment which will store the attempts. Then, in onClick you will check: if(attempts > 5) return; attempts++;
View.OnClickListener click = new View.OnClickListener() {
#Override
public void onClick(View v) {
if(attempts > 5) return;
attempts++;
if ((!phone.getText().toString().isEmpty()) && (!doctorName.getText().toString().isEmpty())
&& (!emailId.getText().toString().isEmpty()) && (!doctorUniqueNumber.getText().toString().isEmpty())){
attempts = 0;
AuthenticateDoctor doctor = new AuthenticateDoctor();
doctor.execute();
}
}
};
Hope it helps
package com.example.m2mai;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
public class RetrieveActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_retrieve);
}
public void getStream(View v)
{
new MyAsyncTask().execute();
}
private class MyAsyncTask extends AsyncTask<String, Void, String>
{
ArrayList<String> mNameList = new ArrayList<String>();
public ArrayList<String> atList=new ArrayList<String>();
public ArrayList<String> dataList=new ArrayList<String>();
protected String doInBackground(String... params)
{
return getData();
}
public long getDateTo()
{
EditText toText = (EditText)findViewById(R.id.dateTo);
String To = toText.getText().toString();
DateFormat dateFormatTo = new SimpleDateFormat("dd/MM/yyyy");
Date dateTo = null;
try {
dateTo = dateFormatTo.parse(To);
} 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();
}
long timeTo = dateTo.getTime();
new Timestamp(timeTo);
return timeTo/1000;
}
protected String getData()
{
String toTS = ""+getDateTo();
String decodedString="";
String returnMsg="";
String request = "http://api.carriots.com/devices/defaultDevice#eric3231559.eric3231559/streams/?order=-1&max=10&at_to="+toTS;
URL url;
HttpURLConnection connection = null;
try {
url = new URL(request);
connection = (HttpURLConnection) url.openConnection();
connection.addRequestProperty("carriots.apikey", "1234567");
connection.addRequestProperty("Content-Type", "application/json");
connection.setRequestMethod("GET");
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
while ((decodedString = in.readLine()) != null)
{
returnMsg+=decodedString;
}
in.close();
connection.disconnect();
JSONObject nodeRoot = new JSONObject(returnMsg);
JSONArray res = nodeRoot.getJSONArray("result");
for (int i = 0; i < res.length(); i++)
{
JSONObject childJSON = res.getJSONObject(i);
if (childJSON.get("data")!=null)
{
String value = childJSON.getString("data");
dataList.add(value);
JSONObject node=new JSONObject(value);
atList.add(node.get("temperature").toString());
}
}
}
catch (Exception e)
{
e.printStackTrace();
returnMsg=""+e;
}
return returnMsg;
}
protected void onPostExecute(String result)
{
for(int i = 0; i < atList.size(); i++)
{
ListView mainListView = (ListView) findViewById(R.id.listView1);
ArrayAdapter<String> mArrayAdapter = new ArrayAdapter<String>(RetrieveActivity.this,android.R.layout.simple_list_item_1,mNameList);
mainListView.setAdapter(mArrayAdapter);
mNameList.add(atList.get(i).toString());
mArrayAdapter.notifyDataSetChanged();
}
Toast.makeText(getApplicationContext(),result, Toast.LENGTH_SHORT).show();
EditText myData1=(EditText)findViewById(R.id.editText1);
myData1.setText(atList.get(0));
}
}
}
How can I actually display a toast without stoping it? Whenever it falls into the catch it is not responding.
............................................................................................................................................................................................................................................................................
If you are using try-catch in a worker thread and want to display Toast, then I am afraid it is not going to work. You will have to do it in Main(UI) thread.
Try following:
try {
dateTo = dateFormatTo.parse(To);
}
catch (java.text.ParseException e) {
your_activity_context.runOnUiThread(new Runnable(){
public void run() {
Toast.makeText(getApplicationContext(),"Please key in the correct input", Toast.LENGTH_LONG).show();
}
});
e.printStackTrace();
}
Try following:
In getDateTo():
try {
dateTo = dateFormatTo.parse(To);
} 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 -1L; // attention here
}
In getData():
long dateTo = -1L;
if((dateTo = getDateTo()) == -1L){
return null;
}
String toTS = "" + getDateTo();
In onPostExecute:
if(result == null) {
return;
}
Make boolean flag = false; globally.
Inside catch block make flag = true;
Run Toast inside an if block like
if (flag) {
Toast.makeText(this, "Sorry, Couldn't find anything!", Toast.LENGTH_LONG).show();
}
inside your onclick method.