Develop Reference

Android SQLiteOpenHelper time-consuming onCreate, need progress bar on first run

The first time my app runs it creates a database in which it loads 6,000 rows from a file in /res/raw. I can't do this asynchronously as the app depends on it entirely. It runs rapidly on my phone - a Moto X - but it's really slow in all my emulators and I'm concerned it could be a bit slower on slower devices thus making the user stare at a blank screen for a few seconds before the app does anything.
Is there a way to put a progress bar while running the overrided SQLiteOpenHelper's onCreate() methood and have it update the progress bar with how far along it is, with a message saying something like "Initializing data for first use!"?

I solved this problem by starting an AsyncTask in onCreate and then only loading the layout at the end of the 'AsyncTask` (or if the data had previously been loaded). It works beautifully as a loading screen. I followed this tutorial http://www.41post.com/4588/programming/android-coding-a-loading-screen-part-1 (which explains the details more) then changed it a bit for my needs (such as loading a raw resource).
I should say that although it does it asynchronously because the main layout hasn't loaded the user has to wait for the loading to complete before he or she can continue, so hopefully that means it doing it asynchronously won't be a problem for you with the app depending on the database.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SharedPreferences sharedPref = getSharedPreferences(getString(R.string.preference_file_key), Context.MODE_PRIVATE);
dataAddedToDB = (sharedPref.getBoolean(PXS_RXS_UPDATE, false));
if (!dataAddedToDB) {
new LoadViewTask(this).execute();
} else {
setContentView(R.layout.activity_main);
}
}
In the AsyncTask it loads the database showing how far it has got and showing your message and then only goes on to show the layout at the end. (BTW, it is helpful to lock the screen orientation while doing this to stop it messing it up).
EDIT: publishProgress(counter); passes the value of where the task has got to to onProgressUpdate().
private class LoadViewTask extends AsyncTask<Void, Integer, Void> {
private Context context;
public LoadViewTask(Context context) {
this.context = context.getApplicationContext();
}
#Override
protected void onPreExecute() {
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.setTitle("Loading...");
progressDialog.setMessage("Initializing data for first use!");
progressDialog.setCancelable(false);
progressDialog.setIndeterminate(false);
// this counts how many line to be added to the database so it can later tell how far it has got.
final Resources resources2 = context.getResources();
InputStream inputStream2 = resources2.openRawResource(R.raw.rawherbaldata);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream2));
int lineCount = 0;
try {
String line;
while ((line = reader.readLine()) != null) {
lineCount++;
}
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
progressDialog.setMax(lineCount);
progressDialog.setProgress(0);
progressDialog.show();
}
#Override
protected Void doInBackground(Void... params) {
HerbalDatabaseOpenHelper mHerbalDbHelper = new HerbalDatabaseOpenHelper(MainActivity.this);
SQLiteDatabase db = mHerbalDbHelper.getWritableDatabase();
int counter = 0;
final Resources resources2 = context.getResources();
InputStream inputStream2 = resources2.openRawResource(R.raw.rawherbaldata);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream2));
db.beginTransaction();
try {
int lineNumber = 1;
String line;
while ((line = reader.readLine()) != null) {
// CODE FOR ENTERING LINE INTO DATABASE
// EDIT: the following keeps the task updated on where it has got to, passing the count to onProgressUpdate()
counter++;
publishProgress(counter);
}
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
db.setTransactionSuccessful();
db.endTransaction();
db.close();
return null;
}
#Override
protected void onProgressUpdate(Integer... values) {
progressDialog.setProgress(values[0]);
}
#Override
protected void onPostExecute(Void result) {
progressDialog.dismiss();
SharedPreferences sharedPref = getSharedPreferences(getString(R.string.preference_file_key), Context.MODE_PRIVATE);
pxsRxsUpdate = true;
SharedPreferences.Editor editor = sharedPref.edit();
editor.putBoolean(PXS_RXS_UPDATE, pxsRxsUpdate);
editor.commit();
// initialize the View
setContentView(R.layout.activity_main);
}
}

You could use another intermediate activity which would show the progress dialog and then send you back to the main activity when done.
First you'll need a static method that a boolean if the DB has already been create.
Then inside of your activity's onCreate call the middleman if necessary:
DbHelper mDbHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (!DbHelper.isDbCreated()) {
Intent intent = new Intent(this, DbActivity.class);
startActivity(intent);
finish();
return;
}
// Do normal stuff like instantiating the helper and so on
mDbHelper = new DbHelper();
...
}
Then inside of this "middleman" activity show the ProgressDialog and create the database.
Once you're done, hide the dialog and go back to your main activity:
mProgress.dismiss();
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
finish();
return;
If your static method isDbCreated() is created properly, you won't reveal the MainActivity's content until the database is created.
EDIT:
Here's the method I use to check for the database. Perhaps it will help you.
public boolean isDbCreated() {
String sDatabasePath = context.getDatabasePath(DB_NAME).getPath();
SQLiteDatabase tmpDb = null;
if (mContext.getDatabasePath(DB_NAME).exists()) {
try {
tmpDb = SQLiteDatabase.openDatabase(sDatabasePath, null,
SQLiteDatabase.OPEN_READONLY);
tmpDb.close();
} catch (SQLiteException e) {
e.printStackTrace();
}
} else {
Log.e(TAG, "DB file doesn't exist.");
// If the parent dir doesn't exist, create it
File parentDir = new File(mContext.getDatabasePath(DB_NAME).getParent());
if (!parentDir.exists()) {
if (parentDir.mkdirs()) {
Log.d(TAG, "Successfully created the parent dir:" + parentDir.getName());
} else {
Log.e(TAG, "Failed to create the parent dir:" + parentDir.getName());
}
}
}
return (tmpDb != null);
}

parse.com calling .save() causes all queries to stop working Android

I have two objects, a establishment object that belongs to a deal object that can be voted upon. If I up/down vote the same deal multiple times, the seventh time I vote the query just sits and does not do anything. The app does not crash, but it also does not save. If I go into another activity that requires a parse.com query that query also will not work. Here is my up vote logic (down voting is identical).
Assume all vars used are initialized before onCreate().
Are my queries getting backed up in a pipe somewhere?
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
upVoteButton = (Button) findViewById(R.id.deal_up_vote_button);
upVoteButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
new UpVoteTask().execute();
}
});
}
// visually changes buttons if they are selected
private void setButtons(Boolean queryDb) {
if (queryDb == true) {
queryParse();
}
// if deal found correctly
if (deal != null) {
// if user found correctly
if (dealVoteUser != null) {
if (dealVoteUser.get("vote").toString().equals("0")) {
upVoteButton.setPressed(false);
downVoteButton.setPressed(true);
} else if (dealVoteUser.get("vote").toString().equals("1")) {
upVoteButton.setPressed(true);
downVoteButton.setPressed(false);
} else if (dealVoteUser.get("vote").toString().equals("2")) {
upVoteButton.setPressed(false);
downVoteButton.setPressed(false);
}
}
}
}
// queries parse and populates vars
private void queryParse(){
ParseQuery<ParseObject> queryDeal = ParseQuery.getQuery("Deal");
queryDeal.whereEqualTo("objectId", deal_id);
try {
deal = queryDeal.getFirst();
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ParseQuery<ParseObject> queryDealVoteUser = ParseQuery
.getQuery("deal_vote_users");
queryDealVoteUser.whereEqualTo("deal", deal).whereEqualTo("user",
ParseUser.getCurrentUser());
try {
dealVoteUser = queryDealVoteUser.getFirst();
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// UpVoteTask AsyncTask
private class UpVoteTask extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
if(upVoteProgressDialog != null){
upVoteProgressDialog.dismiss();
upVoteProgressDialog = null;
}
upVoteProgressDialog = new ProgressDialog(DealsDetailsActivity.this);
// Set progressdialog message
upVoteProgressDialog.setMessage("Saving...");
upVoteProgressDialog.setIndeterminate(false);
// Show progressdialog
upVoteProgressDialog.show();
}
#Override
protected Void doInBackground(Void... params) {
queryParse();
// if deal found correctly
if (deal != null) {
// if user has not voted yet
if (dealVoteUser == null) {
// create new and assign vote to 1
dealVoteUser = new ParseObject("deal_vote_users");
dealVoteUser.put("deal", deal);
dealVoteUser.put("user", ParseUser.getCurrentUser());
dealVoteUser.put("vote", 1);
up_votes = deal.getInt("up_votes") + 1;
down_votes = deal.getInt("down_votes");
// if user already down voted
} else if (dealVoteUser.get("vote").toString().equals("0")) {
// change vote to 1
dealVoteUser.put("vote", 1);
up_votes = deal.getInt("up_votes") + 1;
down_votes = deal.getInt("down_votes") - 1;
// if user already up voted
} else if (dealVoteUser.get("vote").toString().equals("1")) {
// already voted up, remove vote
dealVoteUser.put("vote", 2);
up_votes = deal.getInt("up_votes") - 1;
down_votes = deal.getInt("down_votes");
// if user already voted but cleared vote
} else if (dealVoteUser.get("vote").toString().equals("2")) {
// change vote to 1
dealVoteUser.put("vote", 1);
up_votes = deal.getInt("up_votes") + 1;
down_votes = deal.getInt("down_votes");
}
// calculate overall rating percentage
if ((up_votes + down_votes) != 0) {
rating = (up_votes / (up_votes + down_votes)) * 100;
} else if ((up_votes == 0) && (down_votes == 0)) {
rating = 0;
} else {
rating = 50;
}
deal.put("rating", rating);
deal.put("up_votes", up_votes);
try {
deal.save();
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
dealVoteUser.save();
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
// deal not found problem
}
return null;
}
#Override
protected void onPostExecute(Void result) {
// visually change buttons without querying db
setButtons(false);
//remove progress dialogue
if(upVoteProgressDialog != null){
upVoteProgressDialog.dismiss();
upVoteProgressDialog = null;
}
}
}

Use the saveInBackground method - it will do the same as save, but also save it to your application's cache so that you won't get different values while the data is being saved, so it won't have any apparent effect on your application. It's the best method to save or find (it has a 'sister' method named findInBackground). It acts like an Async task and does not clog your main thread.

I switched all parse calls over to ._____InBackground() and I moved the save logic to onPause(). This way I am not making multiple save calls to parse if the user decides to change their vote multiple times.

Android: XMLPullParser.END_DOCUMENT event never called

When trying to use XMLPullParser the XmlPullParser.END_DOCUMENT event is never called thus code that is suppose to be executed after while loop is never executed. How can I prevent this from happening?
Code Snippet:
int eventType = xpp.getEventType();
if(eventType == XmlPullParser.END_DOCUMENT) {
Log.i("app", "End");
return farmers.getFarmers();
}
while (eventType != XmlPullParser.END_DOCUMENT) {
if(eventType == XmlPullParser.START_DOCUMENT) {
} else if(eventType == XmlPullParser.START_TAG) {
// Do something
} else if(eventType == XmlPullParser.END_TAG) {
// Do something
} else if(eventType == XmlPullParser.TEXT) {
// Do something
}
eventType = xpp.next();
}
if(eventType == XmlPullParser.END_DOCUMENT) {
Log.i("app", "End");
return farmers.getFarmers();
}
return "Some data";
Why is return never called?

Well, you are enclosing the check for XmlPullParser.END_DOCUMENT in a loop that only runs if eventType is not XmlPullParser.END_DOCUMENT, so it will never run that statement.
You need to have
if(eventType == XmlPullParser.END_DOCUMENT) {} outside the loop.
Edit: I saw your edit. Huh, still not detecting the end of the document?.
Try restructuring the loop to use while(true), and put
else if(eventType == XmlPullParser.END_DOCUMENT) {
//Do stuff here
break;
}
inside the loop.
That way, it gets through the whole list, and only leaves the loop when it hits END_DOCUMENT. If loops indefinitely, then I am out of ideas :P.

XmlPullParser with base64encode tag

I am parsing xml packet using XmlPullParser. I am able to parse base64encode tag. My issue here is "I am not able to read full base64encode data. Only part of it is able to read".
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
String elementName = parser.getName();
String namespace = parser.getNamespace();
if(elementName.equals("vCard") && namespace.equals("vcard-temp"))
{
}
// Otherwise, see if there is a registered provider for
// this element name and namespace.
else {
Object provider = ProviderManager.getInstance().getIQProvider(elementName, namespace);
if (provider != null) {
if (provider instanceof IQProvider) {
iqPacket = ((IQProvider)provider).parseIQ(parser);
}
else if (provider instanceof Class) {
iqPacket = (IQ)PacketParserUtils.parseWithIntrospection(elementName,
(Class)provider, parser);
}
}
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("iq")) {
done = true;
}
}else if(eventType == XmlPullParser.TEXT){
String xx = parser.getText();
System.out.println("binaval "+ xx);
}
}

very long string as a response of web service
see this answer here sometimes for the very long string it doesn't work mine was the same case when I posted this question.

unfotunatly the application stopped [duplicate]

This question already has an answer here:
Closed 10 years ago.
Possible Duplicate:
detail of list item in another screen
When I select an item I want the application to navigate to the second activity and take a value of selected item and the related link to the TextView which exists in the second activity. The code should work but when I run it the emulator gives me a message saying "Unfortunately the application stopped". I don't know what to do to make it work?
public class LastActivity extends ListActivity {
/** Called when the activity is first created. */
static List<String> links;
List<String> names;
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
super.onListItemClick(l, v, position, id);
String link=links.get(position);
Intent intent = new Intent(getApplicationContext(),Details.class);
intent.putExtra("name",names.get(position));
intent.putExtra("url",link);
Log.e("n",names.get(position)+"."+ link );
startActivity(intent);
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
links=new ArrayList<String>();
names=new ArrayList<String>();
try{
URL url=new URL(webservice);
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
factory.setNamespaceAware(false);
XmlPullParser xpp = factory.newPullParser();
xpp.setInput(getInputStream(url), "UTF_8");
boolean insideItem = false;
// Returns the type of current event: START_TAG, END_TAG, etc..
int eventType = xpp.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT) {
if (eventType == XmlPullParser.START_TAG) {
if (xpp.getName().equalsIgnoreCase("item")) {
insideItem = true;
} else if (xpp.getName().equalsIgnoreCase("Name")) {
if (insideItem)
names.add(xpp.nextText()); //extract the headline
} else if (xpp.getName().equalsIgnoreCase("url")) {
if (insideItem)
links.add(xpp.nextText()); //extract the link of article
}
}else if(eventType==XmlPullParser.END_TAG && xpp.getName().equalsIgnoreCase("item")){
insideItem=false;
}
eventType = xpp.next(); //move to next element
}
}catch (MalformedURLException e) {
e.printStackTrace();
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, names);
setListAdapter(adapter);
}
private InputStream getInputStream(URL url) {
// TODO Auto-generated method stub
try {
return url.openConnection().getInputStream();
} catch (IOException e) {
return null;
}
}
}
//second class or acticvites
public class Details extends LastActivity{
LastActivity last=new LastActivity();
TextView tv;
TextView url;
String read;
#Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.details);
tv=(TextView) findViewById(R.id.text);
url=(TextView) findViewById(R.id.link);
Intent intent=getIntent();
// receiving data
String name = intent.getStringExtra("name");
String path=intent.getStringExtra("links");
Log.e("Second Screen", name + "." + path);
tv.setText(name);
url.setText(path);
}

I think the problem is with passing putExtra values in the intents. Check your first Activity, you have used the key as "url", but in the details Activity you are using "links" as the key. So you are getting null Pointer Exception. Change it properly.
intent.putExtra("name",names.get(position));
intent.putExtra("url",link);
in Details Activity,
String name = intent.getStringExtra("name");
String path=intent.getStringExtra("url");
instead of,
String path=intent.getStringExtra("links");
In your First Activity you have exntended ListActivty, try to replace it with Activity alone.
Or change your ListView id to #android:list in your xml file.
For more info, look at this question , "Stopped Unexpectedly" tried 10000 times to fix
And also check this for more idea,
Your content must have a ListView whose id attribute is 'android.R.id.list