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'MyApp' has stopped and forcing to close

I'm developing Android app on Android studio using Opencv library and when I try to open my app it opens then right after that it closes and displaying crash message. I'm new on mobile development
Using : OpenCV310, Android Studio 3.0,
public class ScanLicensePlateActivity extends AppCompatActivity {
protected AnylineOcrScanView scanView;
private LicensePlateResultView licensePlateResultView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Set the flag to keep the screen on (otherwise the screen may go dark during scanning)
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.activity_anyline_ocr);
String license = getString(R.string.anyline_license_key);
// Get the view from the layout
scanView = (AnylineOcrScanView) findViewById(R.id.scan_view);
// Configure the view (cutout, the camera resolution, etc.) via json
// (can also be done in xml in the layout)
scanView.setConfig(new AnylineViewConfig(this, "license_plate_view_config.json"));
// Copies given traineddata-file to a place where the core can access it.
// This MUST be called for every traineddata file that is used
// (before startScanning() is called).
// The file must be located directly in the assets directory
// (or in tessdata/ but no other folders are allowed)
scanView.copyTrainedData("tessdata/GL-Nummernschild-Mtl7_uml.traineddata",
"8ea050e8f22ba7471df7e18c310430d8");
scanView.copyTrainedData("tessdata/Arial.traineddata", "9a5555eb6ac51c83cbb76d238028c485");
scanView.copyTrainedData("tessdata/Alte.traineddata", "f52e3822cdd5423758ba19ed75b0cc32");
scanView.copyTrainedData("tessdata/deu.traineddata", "2d5190b9b62e28fa6d17b728ca195776");
// Configure the OCR for license plate scanning via a custom script file
// This is how you could add custom scripts optimized by Anyline for your use-case
AnylineOcrConfig anylineOcrConfig = new AnylineOcrConfig();
anylineOcrConfig.setCustomCmdFile("license_plates.ale");
// set the ocr config
scanView.setAnylineOcrConfig(anylineOcrConfig);
// initialize with the license and a listener
scanView.initAnyline(license, new AnylineOcrListener() {
#Override
public void onReport(String identifier, Object value) {
// Called with interesting values, that arise during processing.
// Some possibly reported values:
//
// $brightness - the brightness of the center region of the cutout as a float value
// $confidence - the confidence, an Integer value between 0 and 100
// $thresholdedImage - the current image transformed into black and white
// $sharpness - the detected sharpness value (only reported if minSharpness > 0)
}
#Override
public boolean onTextOutlineDetected(List<PointF> list) {
// Called when the outline of a possible text is detected.
// If false is returned, the outline is drawn automatically.
return false;
}
#Override
public void onResult(AnylineOcrResult result) {
// Called when a valid result is found
String results[] = result.getText().split("-");
String licensePlate = results[1];
licensePlateResultView.setLicensePlate(licensePlate);
licensePlateResultView.setVisibility(View.VISIBLE);
}
#Override
public void onAbortRun(AnylineOcrError code, String message) {
// Is called when no result was found for the current image.
// E.g. if no text was found or the result is not valid.
}
});
// disable the reporting if set to off in preferences
if (!PreferenceManager.getDefaultSharedPreferences(this).getBoolean(
SettingsFragment.KEY_PREF_REPORTING_ON, true)) {
// The reporting of results - including the photo of a scanned meter -
// helps us in improving our product, and the customer experience.
// However, if you wish to turn off this reporting feature, you can do it like this:
scanView.setReportingEnabled(false);
}
addLicensePlateResultView();
}
private void addLicensePlateResultView() {
RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.main_layout);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
params.addRule(RelativeLayout.CENTER_VERTICAL, RelativeLayout.TRUE);
licensePlateResultView = new LicensePlateResultView(this);
licensePlateResultView.setVisibility(View.INVISIBLE);
mainLayout.addView(licensePlateResultView, params);
licensePlateResultView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startScanning();
}
});
}
private void startScanning() {
licensePlateResultView.setVisibility(View.INVISIBLE);
// this must be called in onResume, or after a result to start the scanning again
scanView.startScanning();
}
#Override
protected void onResume() {
super.onResume();
startScanning();
}
#Override
protected void onPause() {
super.onPause();
scanView.cancelScanning();
scanView.releaseCameraInBackground();
}
#Override
public void onBackPressed() {
if (licensePlateResultView.getVisibility() == View.VISIBLE) {
startScanning();
} else {
super.onBackPressed();
}
}
#Override
protected void onDestroy() {
super.onDestroy();
}}
source code is here.
If possible please help.
Logcat error shown here

Ideally more information regarding the error would be best i.e the opencv library version etc. Given it seems to be an Android issue, I would advise
File and issue or view issues pertaining to this error on their github page. Search for related Android errors to see if they match.
IF you cannot find a related error, file an issue there.

String comparison not working in android [duplicate]

This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 8 years ago.
I am trying to compare two string in my application but it fails to compare. I don't know why it fails.
public void processFinish(String output) {
// TODO Auto-generated method stub
//Toast.makeText(getApplicationContext(), output,Toast.LENGTH_LONG).show();
String check="false";
if(output==check){
//doing something here
}else{
//something here
}
}
the string object output has the value "false" but always the else block is executed why?
I Tried by changing the output=="false" to
output.equals(check)
output.equalsIgnoreCase(check)
output.contentEquals(check)
nothings works...

public void processFinish(String output) {
// TODO Auto-generated method stub
//Toast.makeText(getApplicationContext(), output,Toast.LENGTH_LONG).show();
String check="false";
if(output.trim().equals(check.trim())){
//doing something here
}else{
//something here
}
}
your string getting some unwanted blank space from method trim() remove starting and end blank space :) and .equals is a object class method which compare two string :)

try the following
if(output.contains(check)== true{
//doing something here
}else{
//something here
}

Since instances of String are object, so you can't comparison two objects with ==. To comparison two String, you have to use equals() or equalIgnoreCase() method.
Replace this
if(output==check){
//doing something here
}else{
//something here
}
with...
if(output.equals(check)){
//doing something here
}else{
//something here
}

I think output.equals(check) must works
Or your description maybe not correct.May it is not a string of "false" but "false "?
First ,check their length,then use output.trim().equals(check).

Why is that unreachable code?

I'm generating a question and answers of that randomly. And I want to generate new random arrays and answer options according to those when users chose the correct answer. But it says "unreachable code" when I add a boolean while loop... What is theproblem?
Thanks...
final boolean basadon = false;
while(basadon)
{
Random soru = new Random();
final int[] rastgele = new int[1];
for (int i=0; i<1; i++)
{
rastgele[i]= soru.nextInt(8);
}
ArrayList<Integer> cevap = new ArrayList<Integer>();
for (int k = 0; k <= 7; ++k)
{
cevap.add(k);
}
final Integer[] rastgele2 = new Integer[4];
if (rastgele[0]!=cevap.get(0))
{
rastgele2[0]=cevap.get(0);
}
else
{
rastgele2[0]=cevap.get(3);
}
if (rastgele[0]!=cevap.get(1))
{
rastgele2[1]=cevap.get(1);
}
else
{
rastgele2[1]=cevap.get(3);
}
if (rastgele[0]!=cevap.get(2))
{
rastgele2[2]=cevap.get(2);
}
else
{
rastgele2[2]=cevap.get(3);
}
rastgele2[3]=rastgele[0];
Collections.shuffle(Arrays.asList(rastgele2));
view.setText(countries.get(rastgele[0]));
cevap1.setBackgroundResource(heads[rastgele2[0]]);
cevap1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (rastgele[0]==rastgele2[0])
{
cevap1.setBackgroundResource(heads[8]);
countries.remove(rastgele[0]);
basadon=true;
}
else {
cevap1.setBackgroundResource(heads[9]);
}
}
});
cevap2.setBackgroundResource(heads[rastgele2[1]]);
cevap2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (rastgele2[1]==rastgele[0])
{
cevap2.setBackgroundResource(heads[8]);
countries.remove(rastgele[0]);
basadon=true;
}
else {
cevap2.setBackgroundResource(heads[9]);
}
}
});
cevap3.setBackgroundResource(heads[rastgele2[2]]);
cevap3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (rastgele2[2]==rastgele[0])
{
cevap3.setBackgroundResource(heads[8]);
countries.remove(rastgele[0]);
basadon=true;
}
else {
cevap3.setBackgroundResource(heads[9]);
}
}
});
cevap4.setBackgroundResource(heads[rastgele2[3]]);
cevap4.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (rastgele2[3]==rastgele[0])
{
cevap4.setBackgroundResource(heads[8]);
countries.remove(rastgele[0]);
basadon=true;
}
else {
cevap4.setBackgroundResource(heads[9]);
}
}
});
}
} }

Looks like you start with basedon value as false and later set it to true inside the loop.
So, Change
final boolean basedon = false
while (basedon) {
....
}
to
boolean basedon = false;
do {
....
} while (basedon);

while(basadon) is always false, so you never enter the loop. What you really mean is probably while(basadon==false). Also, don't declare basalon as final boolean because you want to modify its value later, and that will give error.

Why are you declaring all of those variables as final?
If bsadon for example needs to change from false to true, it can't be final. A final value is exactly that, a constant, it won't change.
Don't declare something as final unless you want it to keep the same value for the entire runtime of your program.
You are saying basadon is always "false", that's what final means, so the compiler is telling you you will never enter the while, since you need it to evaluate "true" to enter.
The expression between () in you while clause, needs to evaluate to true for the code to enter.

To your specific question which you have asked:
Why does the compiler give unreachable code warning
The answer is that since the condition in while loop is always false, there is no chance that the code in while loop will get executed. The warning is given to indicate that (given the current code situation) you have wasted your effort in typing that portion of code and it is guaranteed never to be executed. To rectify this, you can remove the final modifier from basedon and put a programming logic to set the value of basedon which will decide whether to enter the loop or not. If you want the loop to always run put while(true).
But I believe that what you wanted to ask was how to make the random question and answer generator. For that you'll have to post a bigger chunk of your code (It looks like you are trying to put a loop over a listener callback ?) and phrase your question to ask specific problems (possibly post a separate question).

It's probably complaining because basadon is known to be false and the body of the while loop cannot be reached. You can suppress the complaint by adding this annotation to the method:
#SuppressWarnings("unused")
You might also try removing the final modifier from the declaration of basadon. That might resolve the issue (but I'm not sure about that).
EDIT I finally noticed that you are trying to modify basadon directly from within your click listeners. That obviously won't work if basadon is final, yet you cannot access local variable unless it is final. I suggest you change basadon to be a (non-final) field of the enclosing class. Then all the warnings and errors should go away.

App crashes when backspace key is pressed

I am trying to learn java while building an android app. I have a points calculator without a button it uses a textchange listener to calculate the total. When backspace key is pressed and the box has null it crashes. I tried validating using the code below (only validated on field to begin with). But it does not work. Any help would be greatly appreciated.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_wwcalc);
etFat = (EditText)findViewById(R.id.editTextFat);
etFiber = (EditText)findViewById(R.id.editTextFiber);
etProtein = (EditText)findViewById(R.id.editTextProtein);
etCarbs = (EditText)findViewById(R.id.editTextCarbs);
tvTotal = (TextView)findViewById(R.id.textViewPoints);
TextWatcher watcher = new TextWatcher() {
#Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
if(isEmpty(etFat) == false){
intFat = Integer.parseInt(etFat.getText().toString());
}
else{
etFat.setText("0");
etFat.hasFocus();
return;
}
intProtein = Integer.parseInt(etProtein.getText().toString());
intFiber = Integer.parseInt(etFiber.getText().toString());
intCarbs = Integer.parseInt(etCarbs.getText().toString());
calculate();
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
#Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
}
};
etFat.addTextChangedListener(watcher);
etProtein.addTextChangedListener(watcher);
etFiber.addTextChangedListener(watcher);
etCarbs.addTextChangedListener(watcher);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_wwcalc, menu);
return true;
}
public void calculate(){
//intTot = intFat + intCarbs + intFiber + intProtein;
intTot = (int) Math.ceil((intFat * (4/35)) + (intCarbs * (4/36.84)) - (intFiber* (4/50))+ (intProtein * (4/43.75)) ) ;
tvTotal.setText(Integer.toString(intTot));
}
private boolean isEmpty(EditText etText)
{
if(etText.getText().toString().trim().length() > 0 || etText.getText().toString().trim() != null)
return false;
else
return true;
}
}
Thanks for the help all. I got it working not sure if it is the best solution if anyone thinks there is a better way let me know. The try catch as suggested by conor catches the exception, then just insert a 0 set focus and select the 0
try {
intFat = Integer.parseInt(etFat.getText().toString());
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
etFat.setText("0");
etFat.hasFocus();
etFat.selectAll();
}

Without seeing the stacktrace it is hard to know but i'm going to make a stab it anyway.
The following piece of your isEmpty() function is allowing false to be returned when the box could still be emtpy.
etText.getText().toString().trim() != null
This means that when you press backspace and clear the field it is empty but your function says it's not. Then the kicker, when your app thinks the field is not empty it tried to parse the contents for an integer value (which is not present). This attempt at parsing throws an exception and crashes your app.
I expect the stacktrace to show the app crashing at this line
intFat = Integer.parseInt(etFat.getText().toString());
It's worth noting that you should always surround calls like Integer.parseInt() with a try, catch block.
Hope that helps.

The exception should be caused by Integer.parseInt,
intFat = Integer.parseInt(etFat.getText().toString());
ntProtein = Integer.parseInt(etProtein.getText().toString());
intFiber = Integer.parseInt(etFiber.getText().toString());
intCarbs = Integer.parseInt(etCarbs.getText().toString());
If you pass string with spaces to parseInt, NumberFormatException will be thrown, you need to trim the text, and then set them, such as,
intFat = Integer.parseInt(etFat.getText().toString().trim());

try this
When backspace is pressed and a field is changed from say "0" to--> "" the operation that is supposed to convert the value to a double fails and crashed my application. "holder.mChoiceRNK"is the " EditView" reference " . If we look at what happens onAfterTextChanged we can set in a default value and then do a select all. The default value of "0" will not cause an error.
Cheers
And happy programming.
holder.mChoiceRNK.doAfterTextChanged {
Log.d(mTAG70, "130xxx 131 Pre Error")
if (holder.mChoiceRNK.text.toString() == "") {
holder.mChoiceRNK.setText("0") // new value if the backspace is pressed to create ""
holder.mChoiceRNK.selectAll()
} else{
Log.d(mTAG70, "130xxx 133 Past Error--> ${holder.mChoiceRNK.text}")
myRNKvotingArray[position].mRNK = holder.mChoiceRNK.text.toString().toDouble()
}}
Alternate solution:
holder.mChoiceRNK.doAfterTextChanged {
try {
myRNKvotingArray[position].mRNK =holder.mChoiceRNK.text.toString().toDouble()
} catch (err:Exception) {
holder.mChoiceRNK.setText("0")
holder.mChoiceRNK.selectAll()
}}

display in textView basic operation result android

i have to show some operations in Android,,,
but Im having some noob problem,
public void calculateButtonPressed() {
// TODO Auto-generated method stub
Button button = (Button) findViewById(R.id.result);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Log.d("myTag", "result biatch");
String text=et.getText().toString();
//toast msg
//Toast msg = Toast.makeText(getBaseContext(),text, Toast.LENGTH_LONG);
// msg.show();
//set Text
tv.setText(text);
//result_tv.setText("copao");
int total = 1+2+3;
result_tv.setText(total);
}
});
}
so the app crashes , as im not using the variable correctly??
If I print the result_tv.setText("copao"); it works fine
but on my basic operation the app crashes,
int total = 1+2+3;
result_tv.setText(total);
so what Im I missing?
thanks!

It is assuming your total value as a string resource Id which might not be available in the R class as a valid resource Id, causing the app to crash.
Change:
result_tv.setText(total);
To:
result_tv.setText(String.valueOf(total));
//OR
result_tv.setText(total + ""); //to parse it as string

use
result_tv.setText(total+""); or result_tv.setText(String.valueOf(total));