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Android (Java): Show Progress-bar while Loading table view data [duplicate]

This question already has answers here:
The application may be doing too much work on its main thread
(21 answers)
Closed 1 year ago.
I have a block of code to load a table view. But for large data, my app is crashing. I want to fix that and also want to show a progress bar while loading the table view data. I tried with the AsyncTask but it is showing Skipped 98 frames! The application may be doing too much work on its main thread.
My onCreate code (Updated): -
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sheet);
myDb = new DBHelper(this);
loadIntentInputs();
setToolbar();
new MyWorker(this).execute();
}
My AsyncTask code (Updated): -
public class MyWorker extends AsyncTask < String , Context , Void > {
private Context context ;
private ProgressDialog progressDialog;
public MyWorker (Context context) {
this.context = context ;
progressDialog = new ProgressDialog ( context ) ;
progressDialog.setCancelable ( false ) ;
progressDialog.setMessage ( "Retrieving data..." ) ;
progressDialog.setTitle ( "Please wait" ) ;
progressDialog.setIndeterminate ( true ) ;
}
# Override
protected void onPreExecute ( ) {
progressDialog.show () ;
}
# Override
protected Void doInBackground ( String ... params ) {
runOnUiThread(new Runnable() {
#Override
public void run() {
showAttendanceTable();
}
});
return null ;
}
# Override
protected void onPostExecute ( Void result ) {
if(progressDialog != null && progressDialog.isShowing()){
progressDialog.dismiss ( ) ;
}
}
}
showAttendanceTable method code (Updated): -
private void showAttendanceTable() {
TableLayout tableLayout = findViewById(R.id.table_layout);
int day_in_month = getDayInMonth(month_year);
int row_size = sid_array.length+1;
TableRow[] rows = new TableRow[row_size];
TextView[] rolls_tv = new TextView[row_size];
TextView[] names_tv = new TextView[row_size];
TextView[][] status_tv = new TextView[row_size][day_in_month+1];
for (int i = 0; i < row_size; i++) {
rolls_tv[i] = new TextView(this);
names_tv[i] = new TextView(this);
for (int j = 1; j <= day_in_month; j++) {
status_tv[i][j] = new TextView(this);
}
}
// for excel file
HSSFSheet hssfSheet = null;
try {
hssfSheet = hssfWorkbook.createSheet(month_year);
} catch (IllegalArgumentException e){
e.printStackTrace();
}
HSSFRow hssfRow;
// setting 1st row
rolls_tv[0].setText("Roll");
names_tv[0].setText("Name");
// setting excel file
hssfRow = hssfSheet.createRow(0);
hssfRow.createCell(0).setCellValue("Roll");
hssfRow.createCell(1).setCellValue("Name");
rolls_tv[0].setTextSize(1,22);
names_tv[0].setTextSize(1,22);
rolls_tv[0].setTypeface(rolls_tv[0].getTypeface(), Typeface.BOLD);
names_tv[0].setTypeface(names_tv[0].getTypeface(), Typeface.BOLD);
rolls_tv[0].setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
names_tv[0].setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
rolls_tv[0].setTextColor(Color.parseColor("#FF000000"));
names_tv[0].setTextColor(Color.parseColor("#FF000000"));
for (int i = 1; i <=day_in_month ; i++) {
String date = String.valueOf(i);
if(i<10) date = "0"+date;
status_tv[0][i].setText(date);
// setting excel file
hssfRow.createCell(i+1).setCellValue(date);
status_tv[0][i].setTextSize(1,22);
status_tv[0][i].setTypeface(status_tv[0][i].getTypeface(), Typeface.BOLD);
status_tv[0][i].setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
status_tv[0][i].setTextColor(Color.parseColor("#FF000000"));
}
// setting rows after 1st row
for (int i = 1; i < row_size ; i++) {
rolls_tv[i].setText(roll_array[i-1]);
names_tv[i].setText(name_array[i-1]);
// setting excel file
hssfRow = hssfSheet.createRow(i);
hssfRow.createCell(0).setCellValue(roll_array[i-1]);
hssfRow.createCell(1).setCellValue(name_array[i-1]);
rolls_tv[i].setTextSize(1,20);
names_tv[i].setTextSize(1,20);
rolls_tv[i].setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
names_tv[i].setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
rolls_tv[i].setTextColor(Color.parseColor("#FF000000"));
names_tv[i].setTextColor(Color.parseColor("#FF000000"));
int count=0;
for (int j = 1; j <=day_in_month ; j++) {
String day = String.valueOf(j);
String month = month_year.substring(0,3);
String year = month_year.substring(4,8);
String status = myDb.getStatus(sid_array[i-1],day+" "+month+" "+year);
if (status!=null && status.equals("A")) {
status_tv[i][j].setText(status);
status_tv[i][j].setBackgroundColor(Color.parseColor("#EF9A9A"));
// setting excel file
hssfRow.createCell(j+1).setCellValue(status);
} else if (status!=null && status.equals("P")) {
status_tv[i][j].setText(String.valueOf(++count));
status_tv[i][j].setBackgroundColor(Color.parseColor("#A5D6A7"));
// setting excel file
hssfRow.createCell(j+1).setCellValue(String.valueOf(count));
}
status_tv[i][j].setTextSize(1,20);
status_tv[i][j].setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
status_tv[i][j].setTextColor(Color.parseColor("#FF000000"));
}
}
for (int i = 0; i < row_size; i++) {
rows[i] = new TableRow(this);
rolls_tv[i].setPadding(20,12,20,12);
names_tv[i].setPadding(20,12,20,12);
if (i==0) {
rows[i].setBackgroundColor(Color.parseColor("#FFD400"));
} else if(i%2==0) {
rows[i].setBackgroundColor(Color.parseColor("#EEEEEE"));
} else {
rows[i].setBackgroundColor(Color.parseColor("#E4E4E4"));
}
rows[i].addView(rolls_tv[i]);
rows[i].addView(names_tv[i]);
for (int j = 1; j <=day_in_month ; j++) {
status_tv[i][j].setPadding(20,12,20,12);
rows[i].addView(status_tv[i][j]);
}
tableLayout.addView(rows[i]);
}
tableLayout.setShowDividers(TableLayout.SHOW_DIVIDER_MIDDLE);
}

The problem is you are running new thread on your doInBackground method and you have placed your showAttendanceTable() code inside runOnUiThread() which is causing too many work to consume main thread.Just copy paste the below code, replace it with your doInBackground() method and everything will work fine.
protected Void doInBackground ( String ... params ) {
showAttendanceTable();
}
return null ;
}
Copy this much part of your code from showAttendanceTable() to onPreExecute() method:
TableLayout tableLayout = findViewById(R.id.table_layout);
int day_in_month = getDayInMonth(month_year);
int row_size = sid_array.length+1;
TableRow[] rows = new TableRow[row_size];
TextView[] rolls_tv = new TextView[row_size];
TextView[] names_tv = new TextView[row_size];
TextView[][] status_tv = new TextView[row_size][day_in_month+1];
for (int i = 0; i < row_size; i++) {
rolls_tv[i] = new TextView(this);
names_tv[i] = new TextView(this);
for (int j = 1; j <= day_in_month; j++) {
status_tv[i][j] = new TextView(this);
}
}

How to apply for loop on first n vlalues of arraylist

I have an arraylist in which I have ESSID, BSSID, Strenght of access Point on first three indexes, and from Index 4 to 6 I have again ESSID, BSSID, Strength of another AccessPoint. I want to store this list in database like first three values save in one row of table. and next three values save in 2nd row of table.
String[] namesArr = new String[arrayList2.size()]; //conver arraylist to array
for (int j = 0; j < arrayList2.size(); j++){
namesArr[j] = arrayList2.get(j);
int length = namesArr[j].length();
for (int k = 0; k < length; k += 3) {
ssid = namesArr[k];
bssid = namesArr[k + 1];
rssid = namesArr[k + 2];
}
insertValues(this);
}
public void insertValues(View.OnClickListener view){
SendData send = new SendData(this);
send.execute(bssid,ssid,rssid);}
I have made a class to store this data in database that works fine.
public class SendData extends AsyncTask<String, Void, String> {
AlertDialog dialog;
Context context;
public SendData(Context context) {
this.context = context;
}
#Override
protected void onPreExecute() {
dialog = new AlertDialog.Builder(context).create();
dialog.setTitle("Message");
}
#Override
protected void onPostExecute(String s) {
dialog.setMessage(s);
dialog.show();
}
#Override
protected String doInBackground(String... voids) {
String data = "";
String result = "";
String MAC = voids[0];
String Name = voids[1];
String Strength = voids[2];
String con_Str = "http://10.5.48.129/Webapi/accesspoints_data/create.php";
try{
URL url = new URL(con_Str);
HttpURLConnection http = (HttpURLConnection) url.openConnection();
http.setRequestMethod("POST");
http.setDoInput(true);
http.setDoOutput(true);
OutputStream out_Stream = http.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out_Stream, "UTF-8"));
JSONObject obj = new JSONObject();
try {
obj.put("BSSID", MAC);
obj.put("ESSID", Name);
obj.put("RSSID", Strength);
} catch (JSONException e) {
e.printStackTrace();
}
data = obj.toString();
writer.write(data);
writer.flush();
writer.close();
out_Stream.close();
InputStream in_Stream = http.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in_Stream, "ISO-8859-1"));
String line = "";
while ((line = reader.readLine()) != null)
{
result += line;
}
reader.close();
in_Stream.close();
http.disconnect();
return result;
} catch (MalformedURLException e){
result = e.getMessage();
} catch (IOException e){
result = e.getMessage();
}
return result;
}
}
SendData class is perfectly working but problem is with for loop.

I think this is result that you are expecting :
List<String> arrayList2 = new ArrayList<>();
arrayList2.add("1");
arrayList2.add("2");
arrayList2.add("3");
arrayList2.add("4");
arrayList2.add("5");
arrayList2.add("6");
arrayList2.add("6");
arrayList2.add("7");
arrayList2.add("8");
arrayList2.add("9");
arrayList2.add("10");
List<String[]> sarrayList = new ArrayList<>();
String[] arr = new String[3];
int i = 0;
for (int j = 0; j < arrayList2.size(); j++)
{
arr[i] = arrayList2.get(j);
i++;
if((j+1)%3==0)
{
sarrayList.add(arr);
i = 0;
arr = new String[3];
}
}
for(String [] sa:sarrayList)
{
for(String s:sa)
{
System.out.println(s);
}
System.out.println("=========");
}
This might not be the most efficient way of doing it. But it splits the ArrayList in to String arrays of length=3 and stores them in a new ArrayList named sarrayList

I would advise to use a datastructure to hold the record. See the code below this is a small example how you could do it
ArrayList<Record> records;
for (int i = 2; i < inputArrayList.size(); i = i + 3){
string ssid = namesArr.get(i - 2);
string bssid = namesArr.get(i - 1);
string rssid = namesArr.get(i);
records.add(new Record(ssid, bssid, rssid));
}
class Record{
string ssid;
string bssid;
string rssid;
// Constructor...
// Getter and setter to be implemented...
}

ok from what i understand you want to divide the arraylist each 3 elements thats how you do it with streams and it will return an a collection of arraylists each one has 3 elements
final int chunkSize = 3;
final AtomicInteger counter = new AtomicInteger();
//arrayList here us your array list
final Collection<List<String>> result = arrayList.stream()
.collect(Collectors.groupingBy(it -> counter.getAndIncrement() / chunkSize))
.values();
and mentioning supermar10 answer you code make a class to map the strings to it like that
class Record{
string ssid;
string bssid;
string rssid;
Record(String ssid,String bssid,String rssid){
this.ssid=ssid;
this.bssid=bssid;
this.rssid=rssid;
}
}
now you have a class to map to now save the records in a list of Record
create a a list in the main class
static List<Record> lists=new ArrayList<>();
then map the data like that
result.stream().forEach(nowList -> saveRecord(nowList));
and thats the save method
static void saveRecord(List<String> list){
lists.add(new Record(list.get(0),list.get(1),list.get(2)));
}

I have simplified it to one loop and also modified insertValues so that it takes 3 more parameters. This
int size = arrayList2.size();
for (int j = 0; j < size; j += 3) {
if (size - j < 3 ) {
break;
}
String ssid = arrayList2.get(j);
String bssid = arrayList2.get(j + 1);
String rssid = arrayList2.get(j + 2);
insertValues(this, ssid, bssid, rssid);
}
if one the other hand ssid and so on are class variables the inside of the loop can be changed to
ssid = arrayList2.get(j);
bssid = arrayList2.get(j + 1);
rssid = arrayList2.get(j + 2);
insertValues();

trying to parse a fetched xml file from one class to another

im using android studio for a school project and im in the final stages now. the only thing i have left is for one class that has 2 spinners, one determining the program, and the other determining the semester, and a button that will then take those two spinners and spit out a URL pertaining to the schedule of that program and semester. The problem is, i dont know how to then take that spit out URL, and parse it into the other java class that displays a schedule. Below you will find the code attached, that works but doesnt display the correct schedule(since its hardcoded)
StringBuffer sb = new StringBuffer();
sb.append("http://branko-cirovic.appspot.com/etcapp/timetables/timetable_"); sb.append(cid); sb.append(semester); sb.append(".xml");
loc = sb.toString();
Toast.makeText(ScheduleMainActivity.this,"You Selected : "
+ loc, Toast.LENGTH_SHORT).show();
Intent toy7 = new Intent(ScheduleMainActivity.this, TimetableMainActivity.class);
toy7.putExtra("Name", loc);
startActivity(toy7);
That is the activity where im creating the intent and using the putExtra to use the data in the next activity
public class GetXML extends AsyncTask<String, Void, String> {
String src = null;
String loc = (String) getIntent().getExtras().get("Name");
#Override
protected String doInBackground(String... params) {
try {
URL url = new URL(loc);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
src = readStream(con.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
return src;
}
#Override
protected void onPostExecute(String result) {
if (src == null)
new AlertDialog.Builder(TimetableMainActivity.this).
setTitle("Error").setMessage("No Schedule Found").
setNeutralButton("Close", null).show();
else {
parseXML(src);
}
setContentView(R.layout.activity_main_timetable);
days = new String[5][10];
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 10; j++) {
int k = i * 10 + j;
days[i][j] = schedule.get(k);
}
}
for (int i = 0; i < 5; i++)
list[i] = new ArrayList<Map<String, String>>();
int count = hours.length;
for (int j = 0; j < 5; j++) {
for (int i = 0; i < count; i++) {
map = new HashMap<String, String>();
map.put("time", hours[i]);
map.put("description", days[j][i]);
list[j].add(map);
}
}
Calendar cal = Calendar.getInstance();
int today = cal.get(Calendar.DAY_OF_WEEK) - 2;
pos = 0;
if (today >= 0 && today <= 4)
pos = today;
ViewPager viewPager = findViewById(R.id.ViewPager);
CustomPagerAdapter adapter = new CustomPagerAdapter(TimetableMainActivity.this, list);
PagerTabStrip pagerTabStrip = findViewById(R.id.pager_tab);
int color = Color.parseColor("#33b7ee");
pagerTabStrip.setTabIndicatorColor(color);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(pos);
}
This is where im getting an error. Im getting an IndexOut of bounds error and the app is crashing
2018-11-20 22:35:19.126 20681-20681/com.example.mr_ru.listview E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.mr_ru.listview, PID: 20681
java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
at java.util.ArrayList.get(ArrayList.java:437)
at com.example.mr_ru.listview.TimetableMainActivity$GetXML.onPostExecute(TimetableMainActivity.java:100)
at com.example.mr_ru.listview.TimetableMainActivity$GetXML.onPostExecute(TimetableMainActivity.java:66)
at android.os.AsyncTask.finish(AsyncTask.java:695)
at android.os.AsyncTask.access$600(AsyncTask.java:180)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:712)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
This is the error btw

List renderer issue in codenameone

I used list renderer and all works fine. Then I kept a extract last clicked item as follows: There are 3 buttons in the renderer. button1 works in all, however button2 and button3 works in some and doesn't work in other? why is it?
If I remove if (lastClickedButton != null) from the code below, it gives NullPointerException for the same button which works in other list items before.
MyCode:
#Override
protected boolean initListModelListEmergencyList(List cmp) {
cmp.setModel(new com.codename1.ui.list.DefaultListModel(emergencyPoliceArray));
cmp.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
for (int i = 0; i < emergencyPoliceArray.size(); i++) {
if (cmp.getSelectedItem() == emergencyPoliceArray.get(i)) {
lastClickedButton = ((GenericListCellRenderer) cmp.getRenderer()).extractLastClickedComponent();
if (lastClickedButton != null) {
System.out.println("Phn no: " + lastClickedButton.getText());
}
}
}
}
}
);
return true;
}
MyConnection:
private void showEmergencyDetails() {
JSONParser p = new JSONParser();
Hashtable<String, Object> test;
try {
test = p.parse(new InputStreamReader(is));
Vector emergencyVector = (Vector) test.get("root");
emergencyPoliceArray = new ArrayList<Map<String, String>>();
for (int j = 0; j < emergencyVector.size(); j++) {
Hashtable hm = (Hashtable) emergencyVector.get(j);
String title = (String) hm.get("title");
String location = (String) hm.get("location");
Vector phn = (Vector) hm.get("phone");
for (int i = 0; i < phn.size(); i++) {
Hashtable hphn = (Hashtable) phn.get(i);
String phone1 = (String) hphn.get("phn1");
String phone2 = (String) hphn.get("phn2");
String phone3 = (String) hphn.get("phn3");
HashMap<String, String> mp = new HashMap<String, String>();
mp.put("Phn", phone1);
mp.put("Phone2", phone2);
mp.put("Phone3", phone3);
mp.put("NameHeading", "Name");
mp.put("PhnHeading", "Phn no.");
mp.put("LocationHeading", "Location");
mp.put("Title", title);
mp.put("Name", title);
mp.put("Location", location);
emergencyPoliceArray.add(mp);
}
}
} catch (IOException ex) {
}
showForm("EmergencyListDetails", null);
}

If there is variance between the renderer entries (e.g. one entry has the button while another doesn't) this might impact all the list and not just the entry where the button is visible.
When you have interaction we strongly recommend avoiding list. Its hackish at best for such use cases and doesn't provide any performance advantages over container for such common cases.

getting text from dynamically created edittext into a button android java

I have created dynamically edittext on my android application like below:
protected void onCreate(Bundle savedInstanceState) {
RelativeLayout layout = (RelativeLayout) findViewById(R.id.linearLayout1);
final EditText[] Et = new EditText[10];
int prevTextViewId = 0;
int add = 0;
int add1 = 0;
for (int a = 0; a < Arr.length; a++) {
Et[a] = new EditText(this);
RelativeLayout.LayoutParams param = new RelativeLayout.LayoutParams(
(int) LayoutParams.WRAP_CONTENT,
(int) LayoutParams.WRAP_CONTENT);
param.leftMargin = 25;
param.topMargin = (a + 1) * (100 + add1);
Et[a].setPadding(5, 23, 5, 5);
Et[a].setLayoutParams(param);
Et[a].setSingleLine(false);
Et[a].setHorizontalScrollBarEnabled(false);
Et[a].setWidth(280);
Et[a].getText().toString();
layout.addView(Et[a]);
add = add + 25;
add1 = add1 + 15;
}
}
And I want to get text from dynamically created edittext into a button like below:
btn_doneAnswer = (Button) findViewById(R.id.btn_doneAnswer);
btn_doneAnswer.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
for (int a = 0; a < Arr.length; a++) {
Et[a] = new EditText(this);
String text += Et[a].getText().toString();
}
Bundle bundle = new Bundle();
Intent i_backToAddItem = new Intent(
AnswerActivityMultiText.this,
QuestionActivityDynamic.class);
bundle.putString("text", text);
bundle.putString("MultiQues", MultiQues);
i_backToAddItem.putExtras(bundle);
startActivity(i_backToAddItem);
}
});
But I am getting error below in the button onclick method at this line Et[a] = new EditText(this);:
The constructor EditText(new View.OnClickListener(){}) is undefined
another below error at this line += in the button onclick method:
Syntax error on token "+=", = expected
Kindly suggest me how I am getting text from dynamically created edittext into a button.
Waiting for reply.
Thanks

you dont have to initialize the EditText again in the onClick. You should directly use the EditText object to get the text. So the line
Et[a] = new EditText(this);
is not required at all!
And for the error with '+=' operator, you are declaring the string and using the operator(+=) in one line. you have to split up the the declaration part out of the for loop and then use '+='. Here's the complete code :
btn_doneAnswer = (Button) findViewById(R.id.btn_doneAnswer);
btn_doneAnswer.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String text;
for (int a = 0; a < Arr.length; a++) {
text += Et[a].getText().toString();
}
Bundle bundle = new Bundle();
Intent i_backToAddItem = new Intent(
AnswerActivityMultiText.this,
QuestionActivityDynamic.class);
bundle.putString("text", text);
bundle.putString("MultiQues", MultiQues);
i_backToAddItem.putExtras(bundle);
startActivity(i_backToAddItem);
}
});

Your problem is in this lines:
for (int a = 0; a < Arr.length; a++) {
Et[a] = new EditText(this);
String text += Et[a].getText().toString();
}
In this line:
Et[a] = new EditText(this);
this is the onClickListener object, you must have class.this (where class is the class name of file that this code is created).
In this other line:
String text += Et[a].getText().toString();
You always create a new String, and instead of created, you make an add. It is a Java concept fail.
You must do this:
String text = "";
for (int a = 0; a < Arr.length; a++) {
Et[a] = new EditText(class_name.this);
text += Et[a].getText().toString();
}