Develop Reference

Android Bluetooth input stream not reading full array

I'm creating an app to read string values over Bluetooth serial port. My data receiving but in two parts. If I send $F00,A,B,0,M# via bluetooth it only reads $ in first part and F00,A,B,0,M# in next part. I provided my code here. Please do correct me if I'm wrong.
InputStream inputStream=null;
int avilableBytes=0;
public ConnectedThread(BluetoothSocket socket){
InputStream temp=null;
try{
temp=socket.getInputStream();
}catch (IOException e){
e.printStackTrace();
}
inputStream=temp;
}
public void run() {
try{
int bytes;
while (true){
try{
avilableBytes=inputStream.available();
if (avilableBytes>0){
byte[] buffer=new byte[avilableBytes];
bytes=inputStream.read(buffer);
final String readMessage=new String(buffer,0,bytes);
bt_handler.obtainMessage(handlerState,bytes,-1,readMessage).sendToTarget();
Log.d("PRAVEEN",readMessage);
}
}catch (IOException e){
e.printStackTrace();
}
}
}catch (Exception e){
e.printStackTrace();
}
}

Data are like stream bytes and can not be processed immediately when it comes with a few bytes. Data will not come all at once as a single packet. You have to use the other byte[] buffer (MainBuffer) in which you will gradually save incoming byte and move the index in that buffer. Then, from time to time (e.g. in the timer once per second) take data from the main buffer and processed it. By default you must implement some data frame with a separator (eg. Data * data * data * - Many ways to do it good or bad). I dealt with this in .net via Xamarin, but just as an example it may be helpfull :
update example, format
In ConnectedThread :
public override void Run()
{
while (true)
{
try
{
int readBytes = 0;
lock (InternaldataReadLock)
{
readBytes = clientSocketInStream.Read(InternaldataRead, 0, InternaldataRead.Length);
Array.Copy(InternaldataRead, TempdataRead, readBytes);
}
if (readBytes > 0)
{
lock (dataReadLock)
{
dataRead = new byte[readBytes];
for (int i = 0; i < readBytes; i++)
{
dataRead[i] = TempdataRead[i];
}
}
Bundle dataBundle = new Bundle();
dataBundle.PutByteArray("Data", dataRead);
Message message = btlManager.sourceHandler.ObtainMessage();
message.What = 1;
message.Data = dataBundle;
btlManager.sourceHandler.SendMessage(message);
}
}
catch (System.Exception e)
{
btlManager.btlState = BTLService.BTLState.Nothing;
}
}
}
In BTLHandler :
public override void HandleMessage(Message msg)
{
switch (msg.What)
{
case 1:
{
byte[] data = msg.Data != null ? msg.Data.GetByteArray("Data") : new byte[0];
btlService.BTLReceiveData(data);
}
break;
}
}
public void BTLReceiveData(byte[] data)
{
lock (dataReadLock)
{
for (int i = 0; i < data.Length; i++)
{
dataRead[dataReadWriteCursor] = data[i];
dataReadWriteCursor++;
}
}
}
In Timer :
int tmpWriteCursor = dataReadWriteCursor;
int tmpReadCursor = dataReadReadCursor;
lock (dataReadLock)
{
int newBytes = dataReadWriteCursor - dataReadReadCursor;
for (int i = 0; i < newBytes; i++)
{
dataReadMain[dataReadReadCursor] = dataRead[dataReadReadCursor++];
}
}
bool odradkovani = false;
string tmpRadek = "";
int lastLineIndex = 0;
List<string> list = new List<string>();
for (int i = LastWriteLineIndex; i < tmpWriteCursor; i++)
{
if (dataReadMain[i] >= 32 && dataReadMain[i] <= 255)
{
tmpRadek += (char)dataReadMain[i];
}
else if (dataReadMain[i] == 13) odradkovani = true;
else if (dataReadMain[i] == 10)
{
if (odradkovani)
{
odradkovani = false;
list.Add(Utils.GetFormatedDateTime(DateTime.Now) + " " + tmpRadek);
tmpRadek = "";
lastLineIndex = i + 1;
}
}
else
{
tmpRadek += "?" + dataReadMain[i].ToString() + "?";
}
}
WriteDataToLog(list);
LastWriteLineIndex = lastLineIndex;

Why I can't send a large amount of data via Bluetooth Android?

I'm still newbie and I need help to coding my Android Studio >0<
I can't to send a long data, although I change the size of "buffer". What should I do ?
This is the receiver program :
public void run() {
InputStream inputStream;
try {
inputStream = mBTSocket.getInputStream();
while (!bStop) {
byte[] buffer = new byte[1024];
if (inputStream.available() > 0)
{
inputStream.read(buffer);
int i = 0;
/*
* This is needed because new String(buffer) is taking the entire buffer i.e. 256 chars on Android 2.3.4 http://stackoverflow.com/a/8843462/1287554
*/
for (i = 0; i < buffer.length && buffer[i] != 0; i++) {}
final String strInput = new String(buffer, 0, i);
/*
* If checked then receive text, better design would probably be to stop thread if unchecked and free resources, but this is a quick fix
*/
}
Thread.sleep(500);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
This are the sender program :
public void sendStringBT(String s)
{
try {
mBTSocket.getOutputStream().write(s.getBytes());
sleep();
Toast.makeText(getApplicationContext(), "Sent...", Toast.LENGTH_SHORT).show();
mBTSocket.getOutputStream().flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
This is how to we call to send data :
sendStringBT(dataPage6); //send data via Bluetooth

I think the problem is in the design of the receiver (using Sleep in an endless cycle ...) I Solved BTL communication in .net Xamarin, but the principle should be the same.
Reading from btlInputStream must be quick and can not use sleep. You use an endless cycle, reading in buffer (OK). Immediately a dune bytes to an auxiliary large buffer (use read / write cursor) and then, for example, in timer treat the data (I suppose you are using some packet protocol)
while (ContinueCycle)
{
int rxlen;
lock (InternalBufferReadLock)
{//Pouze rychle prectu a schovam si do pole
rxlen = USBConnection.BulkTransfer(USBEndPointRead, InternalBufferRead, InternalBufferRead.Length, 0);
Array.Copy(InternalBufferRead, TempBufferRead, rxlen);
}
lock (BufferReadLock)
{
for (int i = 2; i < rxlen; i++)
{
BufferRead[BufferReadWriteCursor] = TempBufferRead[i];
BufferReadWriteCursor++;
}
}
}
and in timer save it to MainBuffer from which the data is processing
if (tmpWriteCursor > tmpReadCursor)
{
lock (BufferReadLock)
{
int newBytes = tmpWriteCursor - tmpReadCursor;
for (int i = 0; i < newBytes; i++)
{
BufferReadMain[BufferReadReadCursor] = BufferRead[BufferReadReadCursor++];
}
}
}
...
bool newline = false;
string tmpRadek = "";
int lastLineIndex = 0;
List<string> list = new List<string>();
for (int i = LastWriteLineIndex; i < tmpWriteCursor; i++)
{
if (BufferReadMain[i] >= 32 && BufferReadMain[i] <= 255)
{
tmpRadek += (char)BufferReadMain[i];
}
else if (BufferReadMain[i] == 13) newline = true;
else if (BufferReadMain[i] == 10)
{
if (newline)
{
newline = false;
list.Add(Utils.GetFormatedDateTime(DateTime.Now) + " " + tmpRadek);
tmpRadek = "";
lastLineIndex = i + 1;
}
}
else
{
tmpRadek += "?" + BufferReadMain[i].ToString() + "?";
}
}

Compare contents of two files line by line

public class MainActivity extends Activity {
FileOutputStream fos;
FileInputStream fOne, fTwo;
ArrayList<String> arr1 = new ArrayList<String>();
ArrayList<String> arr2 = new ArrayList<String>();
ArrayList<String> words = new ArrayList<String>();
ArrayList<String> wordsTwo = new ArrayList<String>();
int count = 0;
int countTwo = 0;
int countThree = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button fileOne = (Button)findViewById(R.id.file1);
Button fileTwo = (Button)findViewById(R.id.file2);
Button compare = (Button)findViewById(R.id.compare);
arr1.add("1");
arr1.add("2");
arr1.add("3");
arr1.add("4");
//arr1.add("3");
arr2.add("1");
arr2.add("2");
fileOne.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
fos = openFileOutput("File1", Context.MODE_PRIVATE);
for(int temp = 0; temp< arr1.size(); temp++)
{
fos.write((arr1.get(temp).getBytes()) );
fos.write(System.getProperty("line.separator").getBytes());
}
fos.close();
fos.flush();
}
catch(Exception e)
{
}
}
});
fileTwo.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
fos = openFileOutput("File2", Context.MODE_PRIVATE);
for(int temp = 0; temp< arr2.size(); temp++)
{
fos.write((arr2.get(temp).getBytes()) );
fos.write(System.getProperty("line.separator").getBytes());
}
fos.close();
fos.flush();
}
catch(Exception e)
{
}
}
});
compare.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
fOne = openFileInput("File1");
fTwo = openFileInput("File2");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Scanner scanFile = new Scanner(new DataInputStream(fOne));
Scanner scanFileT = new Scanner(new DataInputStream(fTwo));
words = new ArrayList<String>();
wordsTwo = new ArrayList<String>();
while (scanFile.hasNextLine())
{
if(scanFile.nextLine()!=null)
{
count++;
}
while(scanFileT.hasNextLine())
{
if(scanFileT.nextLine()!=null)
{
countTwo++;
}
}
}
try
{
fOne.close();
fTwo.close();
scanFile.close();
scanFileT.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Toast.makeText(getBaseContext(), "One : " + count, 1000).show();
Toast.makeText(getBaseContext(), "Two : " + countTwo, 1000).show();
Toast.makeText(getBaseContext(), "Three : " + countThree, 1000).show();
count = 0 ;
countTwo = 0;
countThree = 0;
}
});
}
}
Above is the code to write and read the file. What I did here, write two files and read the contents..Now I have to compare contents of files line by line. What needs to be done?

Try following code. This will give you desired output. I took files from asset directory. So you need to replace that line of code if you are taking files from other directory.
private void compareFiles() throws Exception {
String s1 = "";
String s2 = "", s3 = "", s4 = "";
String y = "", z = "";
// Reading the contents of the files
BufferedReader br = new BufferedReader(new InputStreamReader(
getAssets().open("first.txt")));
BufferedReader br1 = new BufferedReader(new InputStreamReader(
getAssets().open("second.txt")));
while ((z = br1.readLine()) != null) {
s3 += z;
s3 += System.getProperty("line.separator");
}
while ((y = br.readLine()) != null) {
s1 += y;
s1 += System.getProperty("line.separator");
}
// String tokenizing
StringTokenizer st = new StringTokenizer(s1);
String[] a = new String[10000];
for (int l = 0; l < 10000; l++) {
a[l] = "";
}
int i = 0;
while (st.hasMoreTokens()) {
s2 = st.nextToken();
a[i] = s2;
i++;
}
StringTokenizer st1 = new StringTokenizer(s3);
String[] b = new String[10000];
for (int k = 0; k < 10000; k++) {
b[k] = "";
}
int j = 0;
while (st1.hasMoreTokens()) {
s4 = st1.nextToken();
b[j] = s4;
j++;
}
// comparing the contents of the files and printing the differences, if
// any.
int x = 0;
for (int m = 0; m < a.length; m++) {
if (a[m].equals(b[m])) {
} else {
x++;
Log.d("Home", a[m] + " -- " + b[m]);
}
}
Log.d("Home", "No. of differences : " + x);
if (x > 0) {
Log.d("Home", "Files are not equal");
} else {
Log.d("Home", "Files are equal. No difference found");
}
}
Input File 1
Hi
Hello
Chintan
Rathod
Input File 2
Hi
HellO
Chintan
RathoD
Output
08-26 12:07:58.219: DEBUG/Home(2350): Hello3. -- HellO3.
08-26 12:07:58.219: DEBUG/Home(2350): Rathod -- RathoD
08-26 12:07:58.229: DEBUG/Home(2350): No. of differences : 2
08-26 12:07:58.229: DEBUG/Home(2350): Files are not equal
Edit
To get Difference between two files
Use StringUtils library which is provide by Apache and check this Documentation for more about that library.
And modify following lines of code.
int x = 0;
for (int m = 0; m < a.length; m++) {
if (a[m].equals(b[m])) {
} else {
x++;
Log.d("Home", a[m] + " -- " + b[m]);
//to print difference
if (a[m].length() < b[m].length())
Log.d("Home", "" + StringUtils.difference(a[m], b[m]));
else
Log.d("Home", "" + StringUtils.difference(b[m], a[m]));
}
}
Output
08-26 17:51:26.949: DEBUG/Home(17900): 12 -- 123
08-26 17:51:26.949: DEBUG/Home(17900): Difference String : 3
08-26 17:51:26.949: DEBUG/Home(17900): No. of differences : 1
08-26 17:51:26.949: DEBUG/Home(17900): Files are not equal

Try using java.util.Scanner
while (sc1.hasNext() && sc2.hasNext()) {
String str1 = sc1.next();
String str2 = sc2.next();
if (!str1.equals(str2))
System.out.println(str1 + " != " + str2);
}

Change your while loop to the following:
while (scanFile.hasNextLine() && scanFileT.hasNextLine())
{
if(scanFileT.nextLine().equals(scanFile.nextLine()))
{
// The lines are equal.
} else {
// The lines are not equal.
}
}
if(scanFile.hasNextLine() || scanFileT.hasNextLine())
{
// If more lines remain in one of the files, they are not equal.
} else {
// If no content remains in both files, they are equal.
}
Depending on the size of your file, I would recommend some optimisation like checking the file sizes before you go through them line by line.
The overall logic reads as follows; if both have another line, compare it to see if it is equal. If they don't have another line, check if one of them has lines remaining, if so, they are not equal.
Update
After clarifying the objective of the comparison in chat, see the comments to this question, I have come to the conclusion that another comparison would be more effective and, as a matter of fact, correct. The comparison algorithm above works great if comparing the structure of text but not if comparing a data vector which may or may not be sorted. After some discussion, we came to the conclusion that data needs to be sorted or the comparison will blow the complexity to at least O(n^2)which could be done in O(2n) if the data is sorted. Here the algorithm's skeleton:
if(! scanGroupFriends.hasNextLine())
{
//simple sanity check to see if we need to compare at all. In this case, add all friends.
} else {
String nextFriend = scanGroupFriends.nextLine();
while(scanAllFriends.hasNextLine())
{
if(scanAllFriends.nextLine().equals(nextFriend))
{
// Friend already figures, do not add him and advance the list of group friends.
if(scanGroupFriends.hasNextLine())
{
nextFriend = scanGroupFriends.nextLine();
} else {
// There are no more friends in the group, add all remaining friends to list to show.
break; // Terminate the `while` loop.
}
}
}
}
However, I personally think it is bad to make to many assumptions. What I would suggest is that the friends be saved in a Set, a TreeSet for example. Then, serialize the object rather than manually writing it to file. Sets are neat because they hold several interesting objects. For example, you could easily use the following code to remove all friends in a group from the set of all friends:
allFriends.removeAll(groupFriends);
However, be aware that this removes it from the set completely so you should make a copy beforehand.

receive a string message from user input in android and parse to an int so can be stored in an array and compared with another array of integers

I am having a problem with the above task in my android application. I am accepting user input from the EditText widget in the form of String. I accepting numbers from the user so I have to parse them to integers so they can be compared with another array of integers. I have the line:
String message = editText.getText().toString()
then to try and parse the String to an int I have the code line:
int userNumbers = Integer.parseInt(message).
However when I attempt to compare the array userArray with the array numbers I am getting the error that "Incompatible operand types String and Integer.
Can anyone see where my problem is or how I can solve it? Here's my code:
Thanks in advance.
public class MainActivity extends Activity {
public final static String EXTRA_MESSAGE = ".com.example.lotterychecker.MESSAGE";
static boolean bonus = false;
static boolean jackpot = false;
static int lottCount = 0;
Button check;
Integer [] numbers;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//link to the intended web site and get the lottery numbers while the app is opening
try {
Document doc = Jsoup.connect("http://www.national-lottery.co.uk/player/p/drawHistory.do").userAgent("Mozilla").get();
Elements elements = doc.getElementsByClass("drawhistory");
Element table = elements.first();
Element tbody = table.getElementsByTag("tbody").first();
Element firstLottoRow = tbody.getElementsByClass("lottorow").first();
Element dateElement = firstLottoRow.child(0);
System.out.println(dateElement.text());
Element gameElement = firstLottoRow.child(1);
System.out.println(gameElement.text());
Element noElement = firstLottoRow.child(2);
System.out.println(noElement.text());
String [] split = noElement.text().split(" - ");
// set up an array to store numbers from the latest draw on the lottery web page
Integer [] numbers = new Integer [split.length];
int i = 0;
for (String strNo : split) {
numbers [i] = Integer.valueOf(strNo);
i++;
}
for (Integer no : numbers) {
System.out.println(no);
}
Element bonusElement = firstLottoRow.child(3);
Integer bonusBall = Integer.valueOf(bonusElement.text());
System.out.println("Bonus ball: " + bonusBall);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
//called when the user clicks the send button
public void checkNumbers(View view) {
final int SIZE =6;
String [] userArray = new String[SIZE];
//create an intent to display the numbers
Intent intent = new Intent(this, DisplayNumbersActivity.class);
EditText editText = (EditText) findViewById(R.id.enter_numbers);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message );
startActivity(intent);
//parse string message to an int for user numbers
try{
int userNumbers = Integer.parseInt(message); //is this right?
}//try
catch (NumberFormatException e)
{
System.out.println("Not a number" + e.getMessage());
}
Toast.makeText(MainActivity.this, "Here are your numbers", Toast.LENGTH_LONG).show();
for (int count =0; count < SIZE; count ++)
{
if (check.isPressed())
{
userArray[count] = editText.getText().toString();
}
}//for
//compare the two arrays of integers
for (int loop = 0; loop < userArray.length; loop++)
{
for (int loopOther = 0; loopOther < numbers.length; loopOther++)
{
if (userArray[loop] == numbers[loopOther]) //how do I parse this?
{
lottCount++;
}else if (userArray[loop] == bonus)
{
bonus = true;
}
}//for
}//for main

You have this
Integer [] numbers; // numbers is an integer array
You have string array
String [] userArray = new String[SIZE]; // userArray is a string array
You compare like below
if (userArray[loop] == numbers[loopOther])
So you get the error Incompatible operand types String and Integer.
try
if (Integer.parseInt(userArray[loop]) == numbers[loopOther])
Enclosing the above with try catch block
String message = editText.getText().toString();
try{
int userNumbers = Integer.parseInt(message);
//is this right? yes
}
catch (NumberFormatException e)
{
e.printStacktrace();
}

Change String to Int here:
for (int loop = 0; loop < userArray.length; loop++)
{
for (int loopOther = 0; loopOther < numbers.length; loopOther++)
{
if (Integer.valueOf(userArray[loop]) == numbers[loopOther]) //how do I parse this?
{
lottCount++;
}else if (Integer.valueOf(userArray[loop]) == bonus)
{
bonus = true;
}
}//for
}//for main

Parse Like this :
for (int loop = 0; loop < userArray.length; loop++)
{
for (int loopOther = 0; loopOther < numbers.length; loopOther++)
{
if (Integer.parseInt(userArray[loop]) == numbers[loopOther])
{
lottCount++;
}else if (userArray[loop] == bonus)
{
bonus = true;
}
}
}

Why the connection to Gmail server is change my mails situation from "Unread" to "Read"?

I can receive my mails from Gmail Server and show theme on a listview on my Android Project. Yesterday, I started to change my mail's imageview for "unread" or "read" situation. But, then I realized that when my application connected to Gmail Server and receiving my mails, the RECENT mails become SEEN mails. And because of this reason I can't set my imageview's for unread mails.
I mean; I want to receive my mails from Gmail Server without changing their situations on Gmail Server. I want to receive them 3 unread and 4 read as in server.
What should I do for doing that?
My connection code sample is:
public Message[] ConnectionToServer(String email, String password)
throws Exception
{
Properties props = System.getProperties();
props.setProperty("mail.imaps.partialfetch", "false");
URLName server = new URLName("imaps://" + email + ":" + password + "#imap.gmail.com/INBOX");
Session session = Session.getDefaultInstance(props, null);
folder = session.getFolder(server);
if (folder == null)
{
System.exit(0);
}
folder.open(Folder.READ_WRITE);
messages = folder.getMessages();
for (int i = messages.length - 1; i >= 23; i--)
{
Part p = messages[i];
subject = messages[i].getSubject();
if (messages[i].isSet(Flags.Flag.RECENT)) {
isSet = true;
System.out.println("Recent");
isSetlist.add(String.valueOf(isSet));
}
if (messages[i].isSet(Flags.Flag.SEEN))
{
isSet = false;
System.out.println("Read");
isSetlist.add(String.valueOf(isSet));
}
else
{
isSet = true;
System.out.println("Recent");
isSetlist.add(String.valueOf(isSet));
}
body = getText(p);
list.add(body);
}
return (Message[]) messages;
}
I am using getContent in getText() method
public String getText(Part p) throws MessagingException, IOException {
if (p.isMimeType("text/*")) {
boolean textIsHtml = false;
String s = (String) p.getContent();
textIsHtml = p.isMimeType("text/html");
return String.valueOf(s);
}
if (p.isMimeType("multipart/alternative")) {
// prefer html text over plain text
Multipart mp = (Multipart) p.getContent();
String text = null;
for (int i = 0; i < mp.getCount(); i++) {
Part bp = mp.getBodyPart(i);
if (bp.isMimeType("text/plain")) {
if (text == null)
text = getText(bp);
continue;
} else if (bp.isMimeType("text/html")) {
String s = getText(bp);
if (s != null)
return String.valueOf(s);
} else {
return getText(bp);
}
}
return text;
} else if (p.isMimeType("multipart/*")) {
Multipart mp = (Multipart) p.getContent();
for (int i = 0; i < mp.getCount(); i++) {
String s = getText(mp.getBodyPart(i));
if (s != null)
return String.valueOf(s);
}
}
return null;
}

Access the message flags (to determine if the message is SEEN or not) before you access the content. Accessing the content normally sets the SEEN flag.

Try opening the folder in READONLY mode if you don't need to do any modifications - alternately, try preserving the Message flags across getContent calls.