Currently, I am working on a project, where I have to use an Asynctask on multiple fragments. To start with, have I segregated the Asynctask from a Fragment java class, and I have created a new public Java class, where i've put the Asynctask. So far, everything works except the last part (and most important part), where the Asynctask needs to update the textviews on the fragment view.
This is the fragment Java class:
public class DataTabelFragment extends Fragment {
public TextView sensor1;
jsonAsynctask jsonasynctask = new jsonAsynctask(this);
public DataTabelFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate( R.layout.fragment_data_tabel, container, false );
sensor1 = (TextView) view.findViewById( R.id.sensor1Box );
new jsonAsynctask(this).execute();
System.out.println("HEJ MED DIG");
return view;
}
public void inExecute() {
for (int i = 0; i < jsonasynctask.allId.size(); i++) {
sensor1.append( jsonasynctask.allId.get( i ) + " | " + jsonasynctask.allDevice.get( i ) + " | " + jsonasynctask.allTemp.get( i ) + " | " + jsonasynctask.allHum.get( i ) + " | " + jsonasynctask.allBat.get( i ) + " | " + jsonasynctask.allMode.get( i ) + " | " + jsonasynctask.allLux.get( i ) + " | " + jsonasynctask.allDate_time.get( i ) + "\n\n" );
}
}
}
This is the Java Class where in the Asynctask is:
public class jsonAsynctask extends AsyncTask<Void, Void, Void> {
DataTabelFragment dataTabelFragment;
JSONObject idArray, deviceArray, tempArray, humArray, batArray, modeArray, date_timeArray, luxArray;
JSONArray json2;
String basicAuth, line, json_string, json, cxwebURL, credentials, password, username;
String data = "";
String id = "";
List<String> allId = new ArrayList<String>();
List<String> allDevice = new ArrayList<String>();
List<String> allTemp = new ArrayList<String>();
List<String> allHum = new ArrayList<String>();
List<String> allBat = new ArrayList<String>();
List<String> allMode = new ArrayList<String>();
List<String> allDate_time = new ArrayList<String>();
List<String> allLux = new ArrayList<String>();
Gson gson;
ProgressDialog pd;
//HttpsURLConnection connection;
HttpURLConnection connection;
BufferedReader bufferedReader;
URL url;
public jsonAsynctask(DataTabelFragment dataTabelFragment) {
this.dataTabelFragment = dataTabelFragment;
}
public void inBackground() {
username = "xxx";
password = "xxx";
credentials = username + ":" + password;
cxwebURL = "https://" + credentials + "#xxx.com/fetch.php?";
try {
url = new URL( cxwebURL );
connection = (HttpsURLConnection) url.openConnection();
basicAuth = "Basic " + new String( encodeBase64URLSafeString( credentials.getBytes() ) );
connection.setRequestProperty( "Authorization", basicAuth );
connection.setRequestMethod( "GET" );
connection.setRequestProperty( "Content-Type", "application/x-www-form-urlencoded" );
connection.setRequestProperty( "Content-Language", "en-US" );
connection.setUseCaches( false );
connection.setDoInput( true );
connection.setDoOutput( true );
connection.connect();
InputStream stream = connection.getInputStream();
bufferedReader = new BufferedReader( new InputStreamReader( stream ) );
line = "";
while (line != null) {
line = bufferedReader.readLine();
data = data + line;
}
System.out.println( "PRINT DATA HER: " + data );
json2 = new JSONArray( data );
System.out.println( "DET HER ER json2" + json2 );
for (int i = 0; i < json2.length(); i++) {
idArray = json2.getJSONObject( i );
deviceArray = json2.getJSONObject( i );
tempArray = json2.getJSONObject( i );
humArray = json2.getJSONObject( i );
batArray = json2.getJSONObject( i );
modeArray = json2.getJSONObject( i );
date_timeArray = json2.getJSONObject( i );
luxArray = json2.getJSONObject( i );
id = idArray.getString( "id" );
String temp = tempArray.getString( "temp" );
String device = deviceArray.getString( "device" );
String hum = humArray.getString( "hum" );
String bat = batArray.getString( "bat" );
String mode = modeArray.getString( "mode" );
String date_time = date_timeArray.getString( "time" );
String lux = luxArray.getString( "light" );
allId.add( id );
allDevice.add( device );
allTemp.add( temp );
allHum.add( hum );
allBat.add( bat );
allMode.add( mode );
allDate_time.add( date_time );
allLux.add( lux );
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
private static String encodeBase64URLSafeString(byte[] binaryData) {
return android.util.Base64.encodeToString( binaryData, android.util.Base64.URL_SAFE );
}
#Override
protected Void doInBackground(Void... voids) {
inBackground();
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
//pd = new ProgressDialog( new MainActivity() );
//pd.setMessage( "Være sød at vente" );
//pd.setCancelable( false );
//pd.show();
}
#Override
public void onPostExecute(Void result) {
super.onPostExecute( result );
/*
if (pd.isShowing()) {
pd.dismiss();
}*/
gson = new Gson();
json = gson.toJson( data );
json_string = data;
dataTabelFragment.inExecute();
}
}
it is a bad usage of asynctask in your example. In addition, don't hold your data in your asynctask class to retrieve from a fragment. Instead, you should pass your data from onPostExecute method of asynctask to the fragment. The best way is to use an asynctask would be use it with an interface and pass data via that interface. I will put an example, i hope it helps.
public class YourFragment extends Fragment implements YourAsyncTask.YourInterface {
public YourFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_your, container, false);
//do your initial things
.
.
.
YourAsyncTask yourAsyncTask = new YourAsyncTask(this);
yourAsyncTask.execute();
return view;
}
#Override
public void onJobFinishListener(YourDataType yourData) {
//when this method is trigered by your asynctask
//it means that you are in ui thread and update your ui component
//TODO: update ui component with your data
}
}
and below is an asynctask example witn an interface parameter:
public class YourAsyncTask extends AsyncTask {
private YourInterface yourInterfaceListener;
private YourDataType yourData; //this data should be calculated in doInBackground method and send via interface
public YourAsyncTask(YourInterface yourInterfaceListener) {
this.yourInterfaceListener = yourInterfaceListener;
}
#Override
protected Object doInBackground(Object[] objects) {
//do your all background tasks here
.
.
.
yourData = do something here to fill your data..
return null;
}
#Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
yourInterfaceListener.onJobFinishListener(yourData);
}
public interface YourInterface{
void onJobFinishListener(YourDataType yourData);
}
}
Edit: I didn't see above answer when i was writing this. It s also a nice example
Better make use of Interface.
I have also used in one of my project for almost same scenario.
1) Create Interface
public interface AsyncResponse {
void processFinish(String output);
}
2) Initialise interface in constructor of Async task class like you doing
public jsonAsynctask(AsyncResponse asynctaskResponse) {
this.asynctaskResponse = asynctaskResponse;
}
3) Implement interface in your fragment
new jsonAsynctask(new jsonAsynctask.AsyncResponse() {
#Override
public void processFinish(String output) {
// do whatever you want do here
}
}).execute(videouri.toString(), f.getPath());
Hope It will help.
The interface approach solution example by parliament is the best approach. I would also suggest to use a WeakReference on the private YourInterface yourInterfaceListener;
public class YourAsyncTask extends AsyncTask {
private WeakReference<YourInterface> yourInterfaceListener;
private YourDataType yourData; //this data should be calculated in doInBackground method and send via interface
public YourAsyncTask(YourInterface yourInterfaceListener) {
this.yourInterfaceListener = new WeakReference<YourInterface>(yourInterfaceListener);
}
#Override
protected Object doInBackground(Object[] objects) {
//do your all background tasks here
.
.
.
yourData = do something here to fill your data..
return null;
}
#Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
if(yourInterfaceListener.get()!=null){
yourInterfaceListener.get().onJobFinishListener(yourData);
}
}
public interface YourInterface{
void onJobFinishListener(YourDataType yourData);
}
}
Related
I am trying get the dropdown list item from my database in my RecyclerView but whenever i try loading me recyclerView Activity the app crashes.
Code Form my RecyclerView Adapter :
public class Register_Adapter extends RecyclerView.Adapter<Register_Adapter.MyHolder> {
//Line number 40
private Context context;
List<dataRegComplaint> data = Collections.emptyList();
List<productlist> data1 = new ArrayList<>( );
Spinner product;
String total;
public static final int CONNECTION_TIMEOUT = 100000;
public static final int READ_TIMEOUT = 150000;
View v;
public Register_Adapter(complaintReg complaintReg,List<dataRegComplaint> data) {
this.context = complaintReg;
this.data = data;
}
#NonNull
#Override
public MyHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.container_register, viewGroup, false);
return new MyHolder( v );
//Line number 60
}
#Override
public void onBindViewHolder(#NonNull MyHolder myHolder, int i) {
final dataRegComplaint current=data.get(i);
myHolder.client.setText(current.getClientName());
myHolder.location.setText("Location: " + current.getAddress());
myHolder.category.setText("Reason: " + current.getCategory());
myHolder.locationid = current.getlocationid();
myHolder.complaint_register.setOnClickListener( new View.OnClickListener() {
#Override
public void onClick(View v) {
total = current.getlocationid();
Log.e( TAG,"Location id :"+total );
context.startActivity( new Intent( context, Register_New_Complaint.class ) );
}
} );
}
#Override
public int getItemCount() {
return data.size();
}
public class MyHolder extends RecyclerView.ViewHolder{
TextView client,location,category;
Button complaint_register;
String locationid;
public MyHolder(#NonNull View itemView) {
super( itemView );
client = (TextView) itemView.findViewById( R.id.textclient );
location = (TextView) itemView.findViewById( R.id.textlocation );
product = (Spinner) itemView.findViewById( R.id.textproduct1 );
category = (TextView) itemView.findViewById( R.id.textcategory );
complaint_register = (Button) itemView.findViewById( R.id.button_register );
product.setOnItemSelectedListener( (AdapterView.OnItemSelectedListener) context );
}
//Line number 105
}
private class GetProduct extends AsyncTask<String,Void,String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected String doInBackground(String... strings) {
HttpURLConnection conn;
URL url = null;
try {
url = new URL( "http://100.98.115.205:8089/productlist.php" );
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout( READ_TIMEOUT );
conn.setConnectTimeout( CONNECTION_TIMEOUT );
conn.setRequestMethod( "POST" );
conn.setDoOutput( true );
OutputStream outputStream = conn.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter( new OutputStreamWriter( outputStream, "UTF-8" ) );
String post_data = URLEncoder.encode( "total", "UTF-8" ) + "=" + URLEncoder.encode(total, "UTF-8" );
Log.e( TAG, "POST DATAv :"+post_data );
bufferedWriter.write( post_data );
bufferedWriter.flush();
bufferedWriter.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return e1.toString();
}
try {
int response_code = conn.getResponseCode();
// Check if successful connection made
if (response_code == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader( new InputStreamReader( input ) );
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append( line );
}
// Pass data to onPostExecute method
return (result.toString());
} else {
return ("unsuccessful");
}
} catch (IOException e) {
e.printStackTrace();
return e.toString();
} finally {
conn.disconnect();
}
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute( result );
Log.e( TAG, "RESULT :" +result );
try {
JSONArray jArray = new JSONArray( result );
// Extract data from json and store into ArrayList as class objects
for (int i = 0; i < jArray.length(); i++) {
JSONObject json_data = jArray.getJSONObject( i );
productlist fishData = new productlist(
json_data.getString( "prod_name" ) );
data1.add( fishData );
Log.e( TAG, "DATA reesult :" +fishData );
}
populateSpinner();
} catch (JSONException e) {
e.printStackTrace();
}
}
}
private void populateSpinner() {
List<String> lables = new ArrayList<String>();
for(int i = 0; i < data1.size(); i++){
lables.add( data1.get( i ).getSiteid());
Log.e( TAG, "Spinner :" +lables.add( data1.get( i ).getSiteid()) );
}
ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>( context,android.R.layout.simple_spinner_dropdown_item, lables );
spinnerAdapter.setDropDownViewResource( android.R.layout.simple_spinner_dropdown_item );
product.setAdapter( spinnerAdapter );
}
}
LogCat :
java.lang.ClassCastException: nikhil.loginapp.com.complaintReg cannot be cast to android.widget.AdapterView$OnItemSelectedListener
at nikhil.loginapp.com.Register_Adapter$MyHolder.<init>(Register_Adapter.java:105)
at nikhil.loginapp.com.Register_Adapter.onCreateViewHolder(Register_Adapter.java:60)
at nikhil.loginapp.com.Register_Adapter.onCreateViewHolder(Register_Adapter.java:40)
I am getting my data in my PostExecute function but after that its showing error in Spinner and app crashes.
Some one help me out.
This question already has answers here:
Pull to refresh recyclerview android
(7 answers)
Closed 4 years ago.
Bear my English
Whenever any data is added in my database then on refresh the data should be reflected.
And one more thing can you help me Regarding how do I create notification if any new data is Added
I am using:
1) Xampp for Apache
2) Microsoft SQL Server
This is my RecyclerActivtiy
Code:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate( savedInstanceState );
setContentView( R.layout.activity_engineer_recycler );
Bundle bundle = getIntent().getExtras();
service_id = bundle.getString( "empid" );
type_id = bundle.getString( "type" );
if(type_id.equals( "pending" )){
this.setTitle( "Pending Complaint " );
}else if(type_id.equals( "history" )){
this.setTitle( "Complaint History" );
}
Calendar calendar = Calendar.getInstance();
SimpleDateFormat format = new SimpleDateFormat( "dd/MM/yyyy" );
String time = format.format( calendar.getTime() );
Log.e( TAG, "Time" +time );
new AsyncLogin().execute(service_id,type_id, time);
}
private class AsyncLogin extends AsyncTask<String, String, String> {
ProgressDialog pdloding = new ProgressDialog(EngineerRecycler.this);
HttpURLConnection conn;
URL url = null;
#Override
protected void onPreExecute(){
super.onPreExecute();
pdloding.setMessage( "\tLoading.." );
pdloding.setCancelable( false );
pdloding.show();
}
#Override
protected String doInBackground(String... strings) {
try {
serviceid = (String) strings[0];
typeid = (String) strings[1];
time1 = (String) strings[2];
if(typeid.equals( "pending" )){
url = new URL("http://localhost/players.php");
}else if(typeid.equals( "history" )){
url = new URL("http:/localhost/StudentDetails.php");
}
} catch (MalformedURLException e) {
e.printStackTrace();
return e.toString();
}
try {
conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(READ_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
conn.setDoOutput(true);
OutputStream outputStream = conn.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter( new OutputStreamWriter( outputStream, "UTF-8" ) );
String post_data = URLEncoder.encode( "serviceid","UTF-8" ) + "=" + URLEncoder.encode( serviceid, "UTF-8" ) + "&"
+URLEncoder.encode( "time1","UTF-8" ) + "=" + URLEncoder.encode( time1, "UTF-8" );
bufferedWriter.write( post_data );
bufferedWriter.flush();
bufferedWriter.close();
Log.e( TAG, "POST DATA "+post_data );
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return e1.toString();
}
try {
int response_code = conn.getResponseCode();
// Check if successful connection made
if (response_code == HttpURLConnection.HTTP_OK) {
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
// Pass data to onPostExecute method
return (result.toString());
} else {
return ("unsuccessful");
}
} catch (IOException e) {
e.printStackTrace();
return e.toString();
} finally {
conn.disconnect();
}
}
#Override
protected void onPostExecute(String result){
Log.e( TAG,"result"+result );
pdloding.dismiss();
List<DataComplaint> data = new ArrayList<>( );
pdloding.dismiss();
if(result.equals( "No complaint assgin null" )){
Toast.makeText( EngineerRecycler.this, "No Complaint Assign", Toast.LENGTH_SHORT ).show();
}else{
try {
JSONArray jArray = new JSONArray(result);
// Extract data from json and store into ArrayList as class objects
for(int i=0;i<jArray.length();i++){
JSONObject json_data = jArray.getJSONObject(i);
DataComplaint fishData = new DataComplaint(
json_data.getString("comp_desc"),
json_data.getString("comp_reason"),
json_data.getString("ClientName"),
json_data.getString( "SiteName" ),
json_data.getString( "comp_ticketid" ));
data.add(fishData);
}
cAdapter.notifyDataSetChanged();
// Setup and Handover data to recyclerview
complaints = (RecyclerView)findViewById(R.id.complaintList);
cAdapter = new complaintAdapter(EngineerRecycler.this, data,service_id, type_id);
complaints.setAdapter(cAdapter);
complaints.setLayoutManager(new LinearLayoutManager(EngineerRecycler.this));
} catch (JSONException e) {
}
}
}
}
This the code for my Adapter
Code:
#Override
public MyHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.container_complaint, viewGroup, false);
return new MyHolder( v );
}
#Override
public void onBindViewHolder(#NonNull final MyHolder myHolder, final int i) {
final DataComplaint current=data.get(i);
myHolder.textcomplaint.setText(current.complaint);
myHolder.textaddress.setText("Reason: " + current.getAddress());
myHolder.textType.setText("Client : " + current.getComplaint_type());
myHolder.textplace.setText("Location: " + current.getLocation());
myHolder.textticket.setText( current.getTicket());
myHolder.linearLayout.setVisibility( View.GONE );
}
#Override
public int getItemCount() {
return data.size();
}
public class MyHolder extends RecyclerView.ViewHolder {
TextView textcomplaint;
TextView textaddress;
TextView textType,textplace, textticket, textreso;
Button btn, btn1, btn2;
int value1;
SharedPreferences sharedPreferences;
SharedPreferences.Editor editor;
LinearLayout linearLayout;
RelativeLayout relativeView;
public MyHolder(#NonNull View itemView) {
super( itemView );
textcomplaint = (TextView) itemView.findViewById( R.id.textcomplaint );
textaddress = (TextView) itemView.findViewById( R.id.textaddress );
textType = (TextView) itemView.findViewById( R.id.textType );
textticket = (TextView) itemView.findViewById( R.id.ticketid );
textplace = (TextView) itemView.findViewById( R.id.textplace );
btn = (Button) itemView.findViewById( R.id.enter );
btn1 = (Button) itemView.findViewById( R.id.repositry );
btn2 = (Button) itemView.findViewById( R.id.exit );
linearLayout = (LinearLayout) itemView.findViewById( R.id.linear_layout );
relativeView = (RelativeLayout) itemView.findViewById( R.id.view );
}
Here the problem is how implement pull down to refresh function in my recyclerview.
And Where to write function for it whether in RecyclerActivity or in Adapter.
Can anyone help me out regarding this problem.
You can wrap you RecyclerView with the SwipeRefreshLayout for making a pull to refresh.
<android.support.v4.widget.SwipeRefreshLayout
android:id="#+id/refreshView"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.v4.widget.SwipeRefreshLayout>
And you should listen to refresh events for the SwipeRefreshLayout:
refreshView.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
// Load data to your RecyclerView
refreshData();
}
});
I am developing an Application of JSON object Which Returns data into ListView.
if json have data then show data in listview..if dont have date then application is crashes.my application is crashes when json is empty.how to resolve this problem..thanx in advancce
here is android code..
public class EmployeePaymentHistory extends Fragment {
HttpParse httpParse = new HttpParse();
ProgressDialog pDialog;
ListView CategoryListView;
ProgressBar progressBar;
List<String> IdList = new ArrayList<>();
private String TAG = EmployeePaymentHistory.class.getSimpleName();
// Http Url For Filter Student Data from Id Sent from previous activity.
String finalResult ;
HashMap<String,String> hashMap = new HashMap<>();
String ParseResult ;
HashMap<String,String> ResultHash = new HashMap<>();
String FinalJSonObject ;
String TempItem;
ProgressDialog progressDialog2;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_employee_payment, container, false);
CategoryListView = (ListView)view.findViewById(R.id.listview1);
progressBar = (ProgressBar)view.findViewById(R.id.progressBar);
//Receiving the ListView Clicked item value send by previous activity.
TempItem = getActivity().getIntent().getExtras().getString("ListViewValue1");
//Calling method to filter Student Record and open selected record.
HttpWebCall(TempItem);
// Add Click listener on Delete button.
return view;
}
// Method to Delete Student Record
//Method to show current record Current Selected Record
public void HttpWebCall(final String PreviousListViewClickedItem){
class HttpWebCallFunction extends AsyncTask<String,Void,String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(),"Loading Data",null,true,true);
}
#Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
pDialog.dismiss();
//Storing Complete JSon Object into String Variable.
FinalJSonObject = httpResponseMsg ;
//Parsing the Stored JSOn String to GetHttpResponse Method.
new EmployeePaymentHistory.GetHttpResponse(getActivity()).execute();
}
#Override
protected String doInBackground(String... params) {
ResultHash.put("CustomerID",params[0]);
ParseResult = httpParse.postRequest(ResultHash, api.EmployeePayment);
return ParseResult;
}
}
HttpWebCallFunction httpWebCallFunction = new HttpWebCallFunction();
httpWebCallFunction.execute(PreviousListViewClickedItem);
}
// Parsing Complete JSON Object.
private class GetHttpResponse extends AsyncTask<Void, Void, Void>
{
public Context context;
List<Customer> CategoryList;
public GetHttpResponse(Context context)
{
this.context = context;
}
#Override
protected void onPreExecute()
{
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... arg0)
{
try
{
if(FinalJSonObject != null)
{
JSONArray jsonArray = null;
try {
jsonArray = new JSONArray(FinalJSonObject);
JSONObject jsonObject;
Customer category;
CategoryList = new ArrayList<Customer>();
for(int i=0; i<jsonArray.length(); i++)
{
category = new Customer();
jsonObject = jsonArray.getJSONObject(i);
category.CustomerName = jsonObject.getString("date").toString();
category.Customertotal = jsonObject.getString("account").toString();
category.CustomerPaid = jsonObject.getString("total").toString();
category.CustomerUnPaid = jsonObject.getString("status").toString();
CategoryList.add(category);
}
}
catch (JSONException e) {
e.printStackTrace();
}
}
else
{
Toast.makeText(context, "abcc", Toast.LENGTH_SHORT).show();
}
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void result)
{
progressBar.setVisibility(View.GONE);
CategoryListView.setVisibility(View.VISIBLE);
CustomerListAdapterClass adapter = new CustomerListAdapterClass(CategoryList, context);
CategoryListView.setAdapter(adapter);
}
}
}
here is php Api code:
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
include 'DatabaseConfig.php';
$CustomerID= $_POST['CustomerID'];
// Create connection
$conn = new mysqli($HostName, $HostUser, $HostPass, $DatabaseName);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "sELECT b.payerid,a.account as account,b.date as date,b.status as status,b.type as type,sum(b.amount) as total FROM crm_employees a left JOIN sys_transactions b ON a.id = b.payerid where payerid= '$CustomerID' group by b.date ORDER BY a.id desc" ;
$result = $conn->query($sql);
if ($result->num_rows >0) {
while($row[] = $result->fetch_assoc()) {
$tem = $row;
$json = json_encode($tem);
}
} else {
echo "No Results Found.";
}
echo $json;
$conn->close();
}
?>
You need to give the response output same as you are parsing in android side. If you are trying to find a Json object of key name which is not in response then it will crash.
In this scenario you need to handle manually, the values you think it will be null or empty then handle using normal if statements.
Suppose jsonObject.getString("date") object is not fount then using if statements you can handle.
if(jsonObject.getString("date") != null){
//code here
}
"http://soccer.sportsopendata.net/v1/leagues/premier-league/seasons/16-17/standings" - Link Which Iam Trying to parse
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button GetServerData = (Button) findViewById(R.id.GetServerData);
GetServerData.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// WebServer Request URL
String serverURL = "http://soccer.sportsopendata.net/v1/leagues/premier-league/seasons/16-17/standings";
// Use AsyncTask execute Method To Prevent ANR Problem
new LongOperation().execute(serverURL);
}
});
}
private class LongOperation extends AsyncTask<String, Void, Void> {
private final HttpClient Client = new DefaultHttpClient();
private String Content;
private String Error = null;
private ProgressDialog Dialog = new ProgressDialog(MainActivity.this);
String data = "";
TextView uiUpdate = (TextView) findViewById(R.id.textView2);
TextView jsonParsed = (TextView) findViewById(R.id.textView3);
int sizeData = 0;
EditText serverText = (EditText) findViewById(R.id.textView);
protected void onPreExecute() {
// NOTE: You can call UI Element here.
//Start Progress Dialog (Message)
Dialog.setMessage("Please wait..");
Dialog.show();
try {
// Set Request parameter
data += "&" + URLEncoder.encode("data", "UTF-8") + "=" + serverText.getText();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
protected Void doInBackground(String... urls) {
/************ Make Post Call To Web Server ***********/
BufferedReader reader = null;
// Send data
try {
// Defined URL where to send data
URL url = new URL(urls[0]);
// Send POST data request
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(data);
wr.flush();
// Get the server response
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
// Read Server Response
while ((line = reader.readLine()) != null) {
// Append server response in string
sb.append(line + "");
}
// Append Server Response To Content String
Content = sb.toString();
} catch (Exception e) {
Error = e.getMessage();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
return null;
}
protected void onPostExecute(Void unused) {
// NOTE: You can call UI Element here.
// Close progress dialog
Dialog.dismiss();
if (Error != null) {
uiUpdate.setText("Output : " + Error);
}else
{
//Show Response Json Onscreen(Activity)
uiUpdate.setText( Content );
/****************** Start Parse Response JSON Data *************/
String OutputData = "";
try {
JSONObject jsono = new JSONObject(Content);
JSONObject mainObject = jsono.getJSONObject("data");
JSONArray jsonArray = mainObject.getJSONArray("standing");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject object = jsonArray.getJSONObject(i);
// get details2 JSONObject
String position = object.optString("position").toString();
String team = object.optString("team").toString();
OutputData += "Position: " + position + " "
+ "Team Name : " + team + " ";
}
/****************** End Parse Response JSON Data *************/
//Show Parsed Output on screen (activity)
jsonParsed.setText( OutputData );
}catch (JSONException e) {
e.printStackTrace();
}
}
}
}
}
**I am Creating a premier league application which shows all the datas needed for a premier league fan. As Iam new to this I am getting confused over json parsing and getting data from apis. So Can anyone Explain to me how to change my code or Some links which would help me correct it.
Above given is my java code of Main Activity.**
Thank You Everyone for Helping out. But I found my answer from the search over the internet. Here I used VOLLEY to call the link.
JSON PARSER CLASS
public class ParseJSON {
public static String[] position1;
public static String[] team;
public static String[] points;
public static final String JSON_ARRAY = "data";
public static final String CHILD_ARRAY = "standings";
public static final String KEY_ID = "position";
public static final String KEY_NAME = "team";
private JSONObject users = null;
private JSONArray user2=null;
private JSONObject user3=null;
private String json;
public ParseJSON(String json){
this.json = json;
}
protected void parseJSON() {
JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(json);
users = jsonObject.getJSONObject(JSON_ARRAY);
try {
user2=users.getJSONArray(CHILD_ARRAY);
position1 = new String[user2.length()];
team = new String[user2.length()];
points=new String[user2.length()];
for (int i = 0; i < user2.length(); i++) {
JSONObject jo = user2.getJSONObject(i);
try {
user3=jo.getJSONObject("overall");
points[i] = user3.getString("points");
System.out.println("Message me: "+points[i]);
}catch (Exception e)
{
e.printStackTrace();
}
position1[i] = jo.getString(KEY_ID);
team[i] = jo.getString(KEY_NAME);
System.out.println("Message me: "+position1[i]);
System.out.println("Message me: "+team[i]);
}
}catch (Exception e)
{
e.printStackTrace();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Main Activity Class
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
public static final String JSON_URL="http://soccer.sportsopendata.net/v1/leagues/premier-league/seasons/16-17/standings";
private Button buttonGet;
private ListView listView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonGet = (Button) findViewById(R.id.buttonGet);
buttonGet.setOnClickListener(this);
listView = (ListView) findViewById(R.id.listView);
}
#Override
public void onClick(View v) {
sendRequest();
}
private void sendRequest() {
final StringRequest stringRequest = new StringRequest(JSON_URL,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
showJSON(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this, error.getMessage(), Toast.LENGTH_LONG).show();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
}
private void showJSON(String json){
ParseJSON pj = new ParseJSON(json);
pj.parseJSON();
CustomList cl = new CustomList(this, ParseJSON.position1,ParseJSON.team,ParseJSON.points);
listView.setAdapter(cl);
}
}
Custom Class for adding datas to list view
public class CustomList extends ArrayAdapter<String> {
private String[] position1;
private String[] team;
private String[] points;
private Activity context;
public CustomList(Activity context, String[] position1, String[] team, String[] points) {
super(context, R.layout.list_view_layout, position1);
this.context = context;
this.position1 = position1;
this.team = team;
this.points = points;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View listViewItem = inflater.inflate(R.layout.list_view_layout, null, true);
TextView pos1 = (TextView) listViewItem.findViewById(R.id.position1);
TextView teamname = (TextView) listViewItem.findViewById(R.id.teamname);
TextView points1 = (TextView) listViewItem.findViewById(R.id.points);
pos1.setText("Position: "+position1[position]);
teamname.setText("Team: "+team[position]);
points1.setText("Points: "+points[position]);
return listViewItem;
}
}
Step 1 : Use Retroft + RxJava for Asynchronous API calls
Step 2 : Use Gson to Serialize and Deserialize.
Step 3 : Use json to POJO to have a Model Class
Simplify the code.
I have an app that connects to server sends sql request and get JSON answer as JsonArray.
Its Asynktask in seperate class (HTTPRequest.java is my AsyncTask class, Responce.java its my callback interface class) and it works correct.
when I use it in OrderActivity.java like below
#Override //my interface class function
public void onPostExecute(JSONArray Result) {
load(Result);
}
private void load(JSONArray json) {
for(int i=0;i<json.length();i++){
try {
JSONObject jo = json.getJSONObject(i);
Product p = new Product(
jo.getInt("ID"),
jo.getInt("parent"),
jo.getInt("category"),
jo.getString("Item"),
jo.getDouble("Price")
);
products.add(p);
} catch (JSONException e) {
e.printStackTrace();
}
}
it does work and fills product with data, but when I assign to my class variable JSONArray json
JSONArray json = new JSONArray;
.
.
.
#Override
public void onPostExecute(JSONArray Result) {
json = Result;
}
json is null
//HTTPRequest.java
public class HTTPRequest extends AsyncTask<String, Void, Integer> {
private Context context;
private Responce responce;
JSONArray json;
public HTTPRequest(Context context){
this.context = context;
responce = (Responce)context;
}
#Override
protected Integer doInBackground(String... params) {
OutputStream output;
InputStream inputStream = null;
HttpURLConnection connection = null;
String charset = "UTF-8";
Integer result = 0;
try {
URL uri = new URL(params[0]);
connection = (HttpURLConnection) uri.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Accept-Charset", charset);
connection.setRequestProperty("Content-Type", "text/plain; charset=" + charset);
output = connection.getOutputStream();
output.write(params[1].getBytes(charset));
output.close();
int statusCode = connection.getResponseCode();
if (statusCode == 200) {
inputStream = new BufferedInputStream(connection.getInputStream());
json = new JSONArray(getJSON(inputStream));
result = 1;
}
} catch (Exception e) {
e.getLocalizedMessage();
}
return result;
}
#Override
protected void onPostExecute(Integer i) {
super.onPostExecute(i);
if(i == 1) {
responce.onPostExecute(json);
} else {
responce.onPostExecute(null);
}
}
private String getJSON(InputStream inputStream) throws IOException, JSONException {
StringBuffer stringBuffer = new StringBuffer();
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
String line = "";
String result = null;
while((line = bufferedReader.readLine()) != null) {
stringBuffer.append(line.toString());
}
result = stringBuffer.toString();
if(null!=inputStream){
inputStream.close();
}
return result;
}
}
//Responce.java
public interface Responce {
public void onPostExecute(JSONArray Result);
}
//OrderActivity.java
public class OrderActivity extends Activity implements Responce{
ArrayList<Product> products = new ArrayList<Product>();
ProductAdapter productAdapter;
OrderItemAdapter orderItemAdapter;
ListView orderlist;
JSONArray ja;
Button btnBack;
Button btnTakeOrder;
ListView picklist;
HTTPRequest httpRequest;
String url = "http://192.168.3.125:8888/data/";
String query = "select * from vwitems order by category desc";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_order);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
orderlist =(ListView)findViewById(R.id.orderlist);
orderItemAdapter = new OrderItemAdapter(OrderActivity.this);
btnBack = (Button)findViewById(R.id.btnBack);
btnBack.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
productAdapter.filter(0);
}
});
btnTakeOrder = (Button)findViewById(R.id.btnTakeOrder);
btnTakeOrder.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Integer oid = 0;
Order order = new Order(OrderActivity.this);
oid = order.NewOrder(1, 2, 3);
Toast.makeText(OrderActivity.this," " + order.getCount(), LENGTH_SHORT).show();
}
});
orderlist.setAdapter(orderItemAdapter);
picklist = (ListView) findViewById(R.id.picklist);
picklist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
int pid = 0;
if (productAdapter.getItem(position).isCategory()) {
pid = productAdapter.getItem(position).getId();
productAdapter.filter(pid);
} else {
OrderItem oi = new OrderItem();
oi.setItemId(productAdapter.getItem(position).getId());
oi.setItem(productAdapter.getItem(position).getItem());
oi.setPrice(productAdapter.getItem(position).getPrice());
search(oi);
}
}
});
httpRequest = new HTTPRequest(this);
httpRequest.execute(url, query);
}
private boolean search(OrderItem oi){
int size = orderItemAdapter.getCount();
int i = 0;
if(size != 0)
for(OrderItem o : orderItemAdapter.getAll()){
if(o.getItemId() == oi.getItemId()){
orderItemAdapter.getItem(i).setQuantity(orderItemAdapter.getItem(i).getQuantity() + 1);
orderItemAdapter.notifyDataSetChanged();
return true;
}
i++;
}
orderItemAdapter.addItem(oi);
orderItemAdapter.notifyDataSetChanged();
return false;
}
private void load(JSONArray json) {
for(int i=0;i<json.length();i++){
try {
JSONObject jo = json.getJSONObject(i);
Product p = new Product(
jo.getInt("ID"),
jo.getInt("parent"),
jo.getInt("category"),
jo.getString("Item"),
jo.getDouble("Price")
);
products.add(p);
} catch (JSONException e) {
e.printStackTrace();
}
}
productAdapter = new ProductAdapter(OrderActivity.this, products);
picklist.setAdapter(productAdapter);
productAdapter.filter(0);
}
#Override
public void onPostExecute(JSONArray Result) {
load(Result);
}
/*
#Override
public void onPostExecute(JSONArray Result) {
json = Result;
}
**/
}
sorry i forgot include this one
//Order.java
public class Order implements Responce{
private Context context;
private JSONArray json = new JSONArray();
private HTTPRequest httpRequest;
private int OrderID;
private Date OrderDate;
private int OrderTable;
private int Waiter;
private byte OrderStatus;
private List<OrderItem> orderItems;
public Order(Context context){
this.context = context;
}
//some code here...
public Integer NewOrder(Integer guests, Integer waiter, Integer ordertable){
String query = "insert into orders(orderdate, guests, waiter, ordertable) VALUES(NOW()," + guests + ", " + waiter + ", " + ordertable + "); SELECT LAST_INSERT_ID() as ID;";
Integer result = 0;
Connect(query);
try {
JSONObject jo = json.getJSONObject(0);
result = jo.getInt("ID");
} catch (JSONException e) {
e.printStackTrace();
}
return result; //here i got 0 if i init result to 0, null or what ever i init my
}
#Override
public void onPostExecute(JSONArray Result) {
json = Result;
}
private void Connect (String query){
httpRequest = new HTTPRequest(context);
httpRequest.execute("http://192.168.3.125:8888/data/", query);
}
}