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Using Syncroniation wait/notify complete stops program from working Android

I am trying to stop the for loop and wait until the method has finished and continue once it has called onFinish. I was suggested to use either CyclicBarrier or syncronized wait/notify, but neither of them work.
When I run the method without the "stoppers", it always reaches to the onFinish, calling all 3 System.out.prints, but when I add either CyclicBarrier or syncronized it just does not start ticking. Meaning it only prints the first line countDownTimer first call and then stops and does nothing.
Just to make it shorter I have added both stoppers here to show how I did either of them, but I did use them seperately.
What can I do to make it "tick" ?
cyclicBarrier = new CyclicBarrier(2);
object = new Object();
for (int i = 0; i < sentenceList.size() - 1; i++) {
String currentLyricLine = sentenceList.get(i).content;
long diff = sentenceList.get(i+1).fromTime - sentenceList.get(i).fromTime;
int interval = (int) (diff / sentenceList.get(i).wordCount);
if(isFirstLine) {
startLyricCountDownTimer(diff, interval, currentLyricLine, coloredLyricsTextViewFirstLine);
isFirstLine = false;
} else {
startLyricCountDownTimer(diff, interval, currentLyricLine, coloredLyricsTextViewSecondLine);
isFirstLine = true;
}
//First tried with this
synchronized (object) {
try {
object.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
//Then tried with this
try {
cyclicBarrier.await();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (BrokenBarrierException e) {
e.printStackTrace();
}
}
}
private void startLyricCountDownTimer(final long millisInFuture, final int countDownInterval, String lyrics, final ColoredLyricsTextView coloredLyricsText){
System.out.println("countDownTimer first call" );
coloredLyricsText.setText(lyrics);
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
new CountDownTimer(millisInFuture,10) {
#Override
public void onTick(long millisUntilFinished) {
System.out.println("countDownTimer second call + " + millisUntilFinished);
//Do some stuff (irrelevant since it never gets here)
}
#Override
public void onFinish() {
System.out.println("countDownTimer last call" );
//First tried with this
synchronized (object) {
object.notify();
}
//Then tried with this
try {
cyclicBarrier.await();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (BrokenBarrierException e) {
e.printStackTrace();
}
}
}.start();
}
});
}
If i understand correctly then it was also mentioned that I run my loop on UI thread which is why everything stops. And well I do not wish to stop the UI thread, just to wait for one countDownTimer to finish, then start a new loop.

Android postDelayed Handler Inside a For Loop?

Is there any way of running a handler inside a loop?
I have this code but is not working as it does not wait for the loop but executes the code right way:
final Handler handler = new Handler();
final Runnable runnable = new Runnable() {
public void run() {
// need to do tasks on the UI thread
Log.d(TAG, "runn test");
//
for (int i = 1; i < 6; i++) {
handler.postDelayed(this, 5000);
}
}
};
// trigger first time
handler.postDelayed(runnable, 0);
Of course when I move the post delayed outside the loop works but it does not iterate nor execute the times I need:
final Handler handler = new Handler();
final Runnable runnable = new Runnable() {
public void run() {
// need to do tasks on the UI thread
Log.d(TAG, "runn test");
//
for (int i = 1; i < 6; i++) {
}
// works great! but it does not do what we need
handler.postDelayed(this, 5000);
}
};
// trigger first time
handler.postDelayed(runnable, 0);
SOLUTION FOUND:
I need to use asyntask along with Thread.sleep(5000) in the doInBackground method:
class ExecuteAsyncTask extends AsyncTask<Object, Void, String> {
//
protected String doInBackground(Object... task_idx) {
//
String param = (String) task_idx[0];
//
Log.d(TAG, "xxx - iter value started task idx: " + param);
// stop
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//
Log.d(TAG, "xxx - iter value done " + param);
return " done for task idx: " + param;
}
//
protected void onPostExecute(String result) {
Log.d(TAG, "xxx - task executed update ui controls: " + result);
}
}
for(int i = 0; i < 6; i ++){
//
new ExecuteAsyncTask().execute( String.valueOf(i) );
}

Instead of using a for loop, you can let the Runnable instance call itself for a specific number of times. These calls will be posted to UI thread queue so, keep that in mind. Also, since the delay is quite large, make sure the event is still needed when you trigger it next time.
The following code should do it:
final Handler handler = new Handler();
int count = 0;
final Runnable runnable = new Runnable() {
public void run() {
// need to do tasks on the UI thread
Log.d(TAG, "Run test count: " + count);
if (count++ < 5) {
handler.postDelayed(this, 5000);
}
}
};
// trigger first time
handler.post(runnable);

Here is a simple logic I made, without moving the for loop inside runnable.
for(int i = 1; i<=5; i++){
...
new Handler().postDelayed(() -> myFunctionToExecute() , i * 1000);
}
So whenever the loop iterates, it just extends the handler delay. And this way, you may achieve. I was searching for something similar, couldn't find anything, because in my case I already did the implementation of for loop, moving it inside the run() creates a mess

My solution to this problem if anyone has simmilar issues:
int count = 0;
public static void method(param1, param2, param3) {
Runnable r = () -> { //put method inside runnable
View view = listView.getChildAt(position); //action to be complete
if (view != null) { //if action is successfully complete
view.setSelected(true); //do something with this
} else { //do a looper
if (count < 10) { //limited looper to certain number
count++;
method(param1, param2, param3); //run the method again
}
};
Handler h = new Handler(); //create a new Handler and post above thread with it
h.postDelayed(r, 300);
}
Basically, I have created an if-else statement where else statement runs the same method with postDelayed() again for a limited number of trials.

This can be another solution
final Handler handler = new Handler();
Runnable runnable = new Runnable() {
int i;
public void run() {
for (i = 1; i < 6; i++) {
handler.postDelayed(new Runnable() {
#Override
public void run() {
// need to do tasks on the UI thread
Log.d(TAG, "runn test");
}
}, 0);
//Add some downtime
SystemClock.sleep(5000);
}
}
};
new Thread(runnable).start();

JProgressBar not working properly

So my JProgressBar I have set up doesn't work the way I want it. So whenever I run the program it just goes from 0 to 100 instantly. I tried using a ProgressMonitor, a Task, and tried a SwingWorker but nothing I tried works.
Here is my program:
int max = 10;
for (int i = 0; i <= max; i++) {
final int progress = (int)Math.round(
100.0 * ((double)i / (double)max)
);
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
Logger.getLogger(BandListGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
jProgressBar2.setValue(progress);
}
});
}
#MadProgrammer Here is my attempt at making a swing worker and writing each name to the document and updating the progress bar. The program gets to around 86 percent and stops, never creating the finished document. The program creates a blank document. Here are the two methods first is the SwingWorker object I made:
public class GreenWorker extends SwingWorker<Object, Object> {
#Override
protected Object doInBackground() throws Exception {
int max = greenList.size();
XWPFParagraph tmpParagraph;
XWPFRun tmpRun;
FileInputStream file =
new FileInputStream(location + "GreenBandList.docx");
gDocument = new XWPFDocument(OPCPackage.open(file));
for (int i = 0; i < max; i++) {
tmpParagraph = gDocument.getParagraphs().get(0);
tmpRun = tmpParagraph.createRun();
if (greenList.get(i).length() == 1) {
tmpRun.setBold(true);
tmpRun.setText(greenList.get(i));
tmpRun.setBold(false);
} else {
tmpRun.setText(greenList.get(i));//Write the names to the Word Doc
}
int progress = Math.round(((float) i / max) * 100f);
setProgress(progress);
}
return null;
}
}
And here is the code for the button that starts it and has my property change event.
private void GenerateGreenList() throws IOException, InterruptedException {
//Need to fix the bug that removes the Letter Header in Yellow Band list
//********************************************************************\\
//Delete the old list and make a new one
File templateFile = new File(location + "\\backup\\GreenTemplate.docx");
FileUtils.deleteQuietly(new File(location + "GreenBandList.docx"));
FileUtils.copyFile(templateFile, new File(location +
"GreenBandList.docx"));
//Get the New Entries
String[] entries = jTextPane3.getText().split("\n");
for (String s : entries) {
if (s != null) {
greenList.add(s);
}
}
//Resort the list
Collections.sort(greenList);
//Write the names to the document
GreenWorker worker = new GreenWorker();
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if ("progress".equals(evt.getPropertyName())) {
jProgressBar2.setValue((Integer) evt.getNewValue());
}
}
});
worker.execute();
if (worker.isDone()) {
try {
gDocument.write(new FileOutputStream(new File(location + "GreenBandList.docx")));
////////////////////////////////////////////////////////////
} catch (IOException ex) {
Logger.getLogger(BandListGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
JOptionPane.showMessageDialog(null, "Green Band List Created!");
jProgressBar2.setValue(0);
}
}
I used the property change listener from one of your other posts but I don't really understand what the one you wrote does or what it does in general?

Swing is a single threaded environment, that is, there is a single thread which is responsible for processing all the events that occur within the system, including repaint events. Should anything block this thread for any reason, it will prevent Swing from processing any new events, including, repaint events...
So all this ...
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
Logger.getLogger(BandListGenerator.class.getName()).log(Level.SEVERE, null, ex); }
jProgressBar2.setValue(progress);
}
});
Is constantly pausing the Event Dispatching Thread, preventing it from actually doing any updates (or at least spacing them randomly)...
It's also likely that your outer loop is been run from within the context of the EDT, meaning that until it exists, nothing in the Event Queue will be processed. All your repaint requests will be consolidated down to a single paint request and voila, instant filled progress bar...
You really should use a SwingWorker - I know you said you tried one, but you've not shown any code as to your attempt in this regards, so it's difficult to know why it didn't work, however...
SwingWorker and JProgressBar example
SwingWorker and JProgressBar example
SwingWorker and JProgressBar example
SwingWorker and JProgressBar example
SwingWorker and dual welding JProgressBar example
SwingWorker and JProgressBar example
And forgive me if we haven't said this a few times before :P

You are evoking Thread.sleep inside the EvokeLater which means that it is running on another thread than your for loop. i.e., your for loop is completing instantaneously (well, however long it takes to loop from 1 to 100, which is almost instantaneously).
Move Thread.sleep outside of EvokeLater and it should work as you intend.
int max = 10;
for (int i = 0; i <= max; i++) {
final int progress = (int)Math.round(
100.0 * ((double)i / (double)max)
);
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
jProgressBar2.setValue(progress);
}
});
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
Logger.getLogger(BandListGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
}
Edit: agree with #MadProgrammer. It appears this is just an illustrative question, but you should make sure whatever you're trying to accomplish here you use a SwingWorker for.

Android app that generates random words every second and displays them on screen

How can I make an android app that generates a random word every 1 second?
Here is my code:
new Timer().scheduleAtFixedRate(new TimerTask(){
public void run()
{
started = true;
word = "";
for (int i = 0; i < lenght+1; i++)
{
int j = rand.nextInt((max-min) + 1) + min;
word += tr.Translate(j);
}
txt.setText(word);
}
}, 0, 5000);
It seems that my app stops every time it must change the text of the TextView("txt"); how can I make this work?

Undoubtfully, run this within a Thread. Doing this, it will generate the words in background and once it already has, the main UI thread must just append the content to the txt instance.
new Thread(
new Runnable() {
public void run() {
// your stuff
}
}
).start()
To assign the result to the txt object, you'll probably be unable to do it within this thread. To do so, you'll need to declare a Handler in your Activity and use that handler within your thread, so it uses sendMessage() to the main Activity and the Activity just sets the text.
More on this here and here.
---- EDIT ----
As #FD_ says, there is another way to do the update without the use of a Handler. You would just need to call the runOnUiThread() method, something like this:
runOnUiThread(new Runnable() {
public void run() {
txt.setText(your_new_text);
}
});
Another way is using an AsyncTask, which is (talking vaguely) an "evolution" of a thread which makes a lot of stuff for you. More on AsyncTasks here.
---- EDIT ----
This would be one of the ways:
new Thread(
new Runnable() {
public void run() {
new Timer().scheduleAtFixedRate(new TimerTask() {
public void run() {
started = true;
word = "";
for (int i = 0; i < lenght+1; i++)
{
int j = rand.nextInt((max-min) + 1) + min;
word += tr.Translate(j);
}
// This will update your txt instance without the need of a Handler
runOnUiThread(new Runnable() {
public void run() {
txt.setText(word);
}
});
}
}, 0, 5000);
}
}).start();

try this:
int i = 0;
public void changeString() {
started = true;
word = "";
int j = rand.nextInt((max - min) + 1) + min;
word += tr.Translate(j);
txt.setText(word);
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
if (i < lenght + 1) {
changeString();
i++;
}
}
}, 1000);
}
You can do this using timer as well
int i=0;
new Timer().scheduleAtFixedRate(new TimerTask(){
public void run()
{
started = true;
word = "";
int j = rand.nextInt((max-min) + 1) + min;
word += tr.Translate(j);
txt.setText(word);
i++
}
}, 0, 5000);
try the above. The mistake you were making is using a for loop inside run instead use loop run method it-self.

Black view when starting new thread

In my android application I want an automatically refresh every 60 seconds. So I tried it like this:
public void refresh_check() {
Thread myThread = new Thread()
{
int counter = 0;
#Override
public void run() {
MyActivity.this.runOnUiThread(new Runnable(){
#Override
public void run() {
while (counter < 60) {
try {
Thread.sleep(1000);
counter += 1;
System.out.println("Counter: " + counter);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
refresh();
}});
super.run();
}
};
myThread.start();
}
This works in the way that it prints the counter into logcat but in my Application I get a black view. refresh() is just a function with a http request, and this works alone, so the mistake has to be in the thread at any place :/ Can someone help?

You are not utilizing the Thread correctly. Running long tasks on the UI thread is just like not using a Thread at all. To accomplish what you need you should do it like this:
public void refresh_check() {
Thread myThread = new Thread()
{
int counter = 0;
#Override
public void run() {
while (counter < 60) {
try {
Thread.sleep(1000);
counter += 1;
System.out.println("Counter: " + counter); //I think this may cause exception, if it does try removing it
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
refresh(); // In refresh(), use TextView.post(runnable) to post update the TextView from outside the UI thread or use handlers
}});
super.run();
};
myThread.start();
}
Also, take a look at AsyncTask class, it enables you to run long tasks outside UI thread (doInBackground()) as well as update UI with the result from (onPostExecute())