Develop Reference

Writing to storage from handler

I'm trying to write the stream of my array that is coming from Bluetooth module and read from (HandleRead), to the internal storage directly. Is that possible in the first place?
Note that I am reading 100 samples per second. That means the file will fill up quickly. I am not familiar with storage, and my code isn't executed as I expected.
public class MainActivity extends ActionBarActivity implements SensorEventListener {
File Root = Environment.getExternalStorageDirectory();
File Dir = new File (Root.getAbsolutePath()+"/myAppFile");
File file = new File(Dir,"Message.txt");
#Override
protected void onCreate(Bundle savedInstanceState){
String state;
state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)){
if (!Dir.exists()){
Dir.mkdir();
}
}
private void handleRead(Message msg) {
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf);
ByteBuffer buffer = ByteBuffer.wrap(readBuf, 0, readBuf.length);
buffer.order(ByteOrder.BIG_ENDIAN);
buffer.clear();
final String[] strNumbers = readMessage.split("\n");
for (int j = 1; j <= strNumbers.length - 2; j++) {
pressure = Integer.parseInt(readMessage2);
MyFinalPressure = (float) (9.677 +0.831 * pressure);
// trying to store directly to internal sotrage
activity.save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
FileOutputStream fileOutputStream = new FileOutputStream(activity.file);
fileOutputStream.write((int) MyFinalPressure);
fileOutputStream.close();
Toast.makeText(activity.getApplicationContext(),"Message saved ", Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e){
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}
}
}

It appears you are not setting the FileOutputStream to 'append' (you need to add 'true' as 2nd parameter in constructor.)
This would write over the file from the file-start every time
also your 'setOnClickListener' is INSIDE your loop. This doesn't do anything for you as far as I can tell.
I recommend always setting up UI elements in a private void setupUI() {...} method that onCreate calls. The public void onClick(View v) {buttonForSavingPresssed()} where buttonForSavingPressed(){...} is the 'logic' of your onClick() method.
This will help you clean up the class and not have stray onClickListener assignments, etc.
My guess is that either your multiple assignments is very inefficient, since clickListeners aren't cheap, or... the clickListener might not even work at all because of a timing issue (if your loop is long running and you press the button and the listener has already been swapped for a new one)
I've cleaned up your code some, There are some suggestions and some log statements that should help you figure out what is going on.
// this is inside your onCreate()
...
activity.save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) { buttonPressed();}
});
...
// Here is where you would put your logic when the button is presssed
public void buttonPressed(){
Toast.makeText(activity.getApplicationContext(),"Button Pressed ",
Toast.LENGTH_SHORT).show();
}
// you should make 'helper' functions that consolidate separate pieces of logic like this,
// that way you can more easily track what is happening in each method.
// Plus it helps keep each method shorter for ease of understanding, etc.
public void writeToFile(float finalPressure){
Log.d(LOG_TAG // where LOG_TAG is the String name of this class
"writeToFile(float) called." );
try{
// true here for 'append'
FileOutputStream fileOutputStream = new
FileOutputStream(activity.file, true);
fileOutputStream.write((int) finalPressure);
fileOutputStream.close();
}catch (FileNotFoundException e){
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
// now back to your handleRead, is this method called async wenever
// a message is read? Then wouldn't this be called a lot? I'm lost as to why
// you had the button in here at all.
private void handleRead(Message msg) {
Log.d(LOG_TAG // where LOG_TAG is the String name of this class
"handleRead(Message) called." );
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf);
ByteBuffer buffer = ByteBuffer.wrap(readBuf, 0, readBuf.length);
buffer.order(ByteOrder.BIG_ENDIAN);
buffer.clear();
final String[] strNumbers = readMessage.split("\n");
Log.d(LOG_TAG // where LOG_TAG is the String name of this class
"strNumbers length: " + strNumbers.length );
for (int j = 1; j <= strNumbers.length - 2; j++) {
pressure = Integer.parseInt(readMessage2);
MyFinalPressure = (float) (9.677 +0.831 * pressure);
// trying to store directly to internal sotrage
writeToFile(MyFinalPressure);
}
}

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);
}

FTDI Android - create new activity

This code is able to make the android device as a USB host for the hardware model. It also can read data from the hardware correctly in Main Activity. However, as soon as I moved it to another activity, everything still works but the data reading is incorrect.
For instance, I'm trying to write the data read into file. First activity is to input filename and just a button to send to another activity. The code below is in the second activity
public class Temp extends Activity {
private FileOutputStream outputStream;
public static D2xxManager ftD2xx= null;
Handler mHandler = new Handler();
FT_Device ftDev = null;
int devCount = 0;
UsbDevice device = null;
TextView Text =null;
String temp = null;
_4DPoint P = null;
int rd = 0;
byte[] byt = null;
byte[] Fdata = null;
String outp = "";
String From_Serial = "";
int Min = -1;
String fileName;
Context c;
final Runnable updateResults = new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
Text.setText("" + Min + '\n' + temp);
}
};
public void getData(){
try {
outputStream = openFileOutput(fileName, Context.MODE_PRIVATE);
byt = new byte[256];//{(byte)'a','b','c','d',};
Toast.makeText(getBaseContext(), "start " + fileName , Toast.LENGTH_LONG).show();
Text = (TextView)findViewById(R.id.test2);
device = (UsbDevice) getIntent().getParcelableExtra("USB");
ftD2xx = D2xxManager.getInstance(c);
ftD2xx.addUsbDevice(device);
devCount = ftD2xx.createDeviceInfoList(c);
if (devCount > 0) {
ftDev = ftD2xx.openByUsbDevice(c, device);
}
if( ftDev.isOpen() == true ) {
ftDev.setBitMode((byte)0 , D2xxManager.FT_BITMODE_RESET);
ftDev.setBaudRate(38400);
ftDev.setDataCharacteristics(D2xxManager.FT_DATA_BITS_8, D2xxManager.FT_STOP_BITS_1, D2xxManager.FT_PARITY_NONE);
ftDev.setFlowControl(D2xxManager.FT_FLOW_NONE, (byte) 0x0b, (byte) 0x0d);
Thread t = new Thread() {
public void run() {
int i;
while(true){
rd=0;
while (rd==0){
rd = ftDev.read(byt, 14);
}
for(i=0; i<rd; i++)
outp += (char)byt[i];
From_Serial = new String(outp);
P = new _4DPoint(From_Serial);
temp = String.format("%s: %f %f %f %f %d\n", From_Serial, P.R, P.G, P.B, P.L, P.camera);
try {
outputStream.write(temp.getBytes());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
outp = "";
mHandler.post(updateResults);
}
}
};
t.start();
}
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (D2xxException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_color);
// Show the Up button in the action bar.
setupActionBar();
Intent intent = getIntent();
fileName = intent.getStringExtra("File Name");
c = this;
getData();
}
The set up should be fine since it's reading data from hardware, but the data read is incorrect.
Also, I'm wondering why we need to create new thread while reading data. I tried not creating new thread and it didn't work well, but still have no idea why? I tried to contact the person who wrote the code to read data but no reply.
Any help would be really appreciated :)

You state that you receive data, therefor I think you should look at your ftDev settings. Try for example to set ftDev.setBaudRate(115200) (this worked for me) or try playing with your other ftDev Settings a little bit.
The settings I use in my programm are:
int baudRate = 115200;
byte stopBit = 1; /*1:1stop bits, 2:2 stop bits*/
byte dataBit = 8; /*8:8bit, 7: 7bit*/
byte parity = 0; /* 0: none, 1: odd, 2: even, 3: mark, 4: space*/
byte flowControl = 1; /*0:none, 1: flow control(CTS,RTS)*/
If this won't work, it is wise to first check this data communication with a computer program e.g. or to analyse the incomming 'wrong' data.

Android Load File From Res Error

I'm trying to load a text file from res/raw. I've looked at several code snippets and tried implementing a few ways but none seem to work for me. The code I currently am trying to get to work is this
TextView helloTxt = (TextView)findViewById(R.id.hellotxt);
helloTxt.setText(readTxt());
}
private String readTxt() {
InputStream inputStream = getResources().openRawResource(R.raw.hello);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
int i;
try {
i = inputStream.read();
while (i != -1) {
byteArrayOutputStream.write(i);
i = inputStream.read();
}
inputStream.close();
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return byteArrayOutputStream.toString();
But it suffers from te same problem as all the others do.
a) (TextView)findViewById(R.id.hellotxt); says it depreciated and Eclipses recommends Migrating code.
b) getResources() isn't recognized and just suggests I add a method called getResources().
Initially I wanted to use assets folder but got the same error as b) but with getAssets().
This is a seperate class file I'm implementing this is called public class PassGen{} with one method at the moment called public String returnPass(){}

The functions getAssets and getResources should be called from a Context.
If you call it from within an Activity class it doesn't need a prefix, but otherwise you'd need to pass the context to the class that needs the functions and call e.g. context.getAssets().

Activity Class:
public class ReadFileActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Read read = new Read(getApplicationContext());
TextView helloTxt = (TextView) findViewById(R.id.hellotxt);
helloTxt.setText(read.readTxt());
}
}
Read Class:
public class Read {
Context ctx;
public Read(Context applicationContext) {
// TODO Auto-generated constructor stub
this.ctx = applicationContext;
}
public String readTxt() {
InputStream inputStream = ctx.getResources().openRawResource(R.raw.hello);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
int i;
try {
i = inputStream.read();
while (i != -1) {
byteArrayOutputStream.write(i);
i = inputStream.read();
}
inputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return byteArrayOutputStream.toString();
}
}

Memory-leak android using arrays and files

I'm developing a dictionary using *.txt files in /raw directory, also I have a history (current 18 entries).
Every OnResume() I'm getting history entries from file on SDCard and filling ListArray's than use ArrayAdapter to fill a ListView.
I can't understand why I have a big memory leak (every onResume() adds about 4-6 MB to the memory). Please help me.
Here is my code:
public class SecondTab extends Activity {
ListView lv1;
ArrayList <String> ArrayHist = new ArrayList <String>();
ArrayList <String> ArrayHistMin = new ArrayList <String>();
BufferedReader Buffer;
InputStream file;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.hist);
SetContent();
if (ru.andr.dictu.FirstTab.myErrorInHist)
{
Toast.makeText(this, getString(R.string.err_hist), Toast.LENGTH_LONG).show();
}
}
public void SetContent()
{
//show History entries
//trying to solve memory leak
try
{
ArrayHist.clear();
ArrayHistMin.clear();
}
catch (Exception e){}
ArrayHist=null;
ArrayHistMin=null;
ArrayHist = new ArrayList <String>();
ArrayHistMin = new ArrayList <String>();
Buffer=null;
file=null;
if (ru.andr.dictu.FirstTab.myErrorInHist!=true)
{
//filling arrays
try {
file = new FileInputStream(ru.andr.dictu.history_func.File_hist()); //getting name of file from common store
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Buffer = new BufferedReader(new InputStreamReader(file));
try {
String Str;
int counter_hist_content = 0;
while ( (Str = Buffer.readLine()) != null){ //reading from history file
String myTrimStr = Str.trim();
ArrayHistMin.add(myTrimStr.substring(0, myTrimStr.indexOf(";;")).intern()); //main word
ArrayHist.add(myTrimStr.substring(myTrimStr.indexOf(";;")+2).intern()); //ususaly translate
if (counter_hist_content==50) break;//needs only 50 entries
counter_hist_content++;
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try
{
//closing files, buffers
file.reset();
file.close();
Buffer.reset();
Buffer.close();
}catch (Exception e) {}
}
lv1 = (ListView)findViewById(R.id.history);
lv1.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item_hist, ArrayHistMin));
lv1.setTextFilterEnabled(true);
lv1.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
changeClass (position , ArrayHist.get(position));
}
});
lv1.setOnItemLongClickListener(new OnItemLongClickListener(){
#Override
public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
ru.andr.dictu.myspeak.text=null;
ru.andr.dictu.myspeak.text=ArrayHistMin.get(arg2);
if (ru.andr.dictu.myspeak.text.indexOf("[")!=-1)
ru.andr.dictu.myspeak.text=ru.andr.dictu.myspeak.text.substring(0,ru.andr.dictu.myspeak.text.indexOf("[")).intern();
speakClass();
return true;
}
});
}
public void speakClass() {
Intent intent = new Intent();
intent.setClass(this, myspeak.class);
startActivity(intent);
}
public void changeClass(int position, String extArray) {
Intent intent = new Intent();
intent.setClass(this, List.class);
intent.putExtra(List.results, extArray.toString().intern());
startActivity(intent);
getParent().overridePendingTransition(R.anim.zoom_enter, R.anim.zoom_exit);
}
#Override protected void onPause() {super.onPause(); }
#Override
protected void onResume()
{
super.onResume();
SetContent();
}

My guess is the new InputStreamReader(file) is being leaked. You need to close this reader.
Though if this does not solve the problem, dump the hprof data and check using MAT tool in eclipse. You can point out which class is taking maximum heap.
Edit: You can dump hprof in DDMS view. It is one of the buttons right above where processes are displayed