Develop Reference

Java Swing Use Date for Timer

Trying to make a timer that displays the time that has elapsed since a button has been pressed. I am using a Date instance and am trying to have it be initalized to 00:00:00 and have it increase by seconds, mins, then hours. it works as just a clock of the current time if I do not enter any values into Date currentTime = new date()
Here is my code, I have tried setting the Date to all 0 values, and it displays as all zeros, but when my button is pressed, it no longer functions as a timer. What is the problem?
Timer timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Date currentTime = new Date(0,0,0,0,0,0);
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
laserOnTimeTF.setText(sdf.format(currentTime));
}
});
laserOnOff.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (!laserSetting) {
timer.start();
laserSetting = true;
laserOnOff.setText("Laser On");
} else {
timer.stop();
laserSetting = false;
laserOnOff.setText("Laser Off");
}
}
});

That Date constructor is deprecated, like all Date constructors other than the one that takes a milliseconds argument. APIs are deprecated for a reason, usually because they don’t work as intended. To be notified when you use deprecated APIs, turn on all compiler warnings in your IDE, and pay attention to those warnings.
Date is not a good fit for storing elapsed time, since it represents an absolute point in time. The class which is designed to represent a time difference is java.time.Duration.
You can calculate a Duration from two time values. The simplest time value is probably Instant, so you will want a private field of type Instant in the class which creates the Timer and adds a listener to the button, to keep track of when the button was pressed:
private Instant timeOfLastButtonPress;
Then you can initialize it each time the button is actually pressed:
laserOnOff.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (!laserSetting) {
timeOfLastButtonPress = Instant.now();
timer.start();
laserSetting = true;
laserOnOff.setText("Laser On");
} else {
timer.stop();
laserSetting = false;
laserOnOff.setText("Laser Off");
}
}
});
Finally, your Timer can calculate the Duration using Duration.between:
Duration elapsedTime =
Duration.between(timeOfLastButtonPress, Instant.now());
If you’re using Java 9 or later, you can extract the numbers from a Duration directly:
Timer timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Duration elapsedTime =
Duration.between(timeOfLastButtonPress, Instant.now());
laserOnTimeTF.setText(String.format("%02d:%02d:%02d",
elapsedTime.toHoursPart(),
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart()));
}
});
In Java 8, you will need to calculate it yourself:
Timer timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Duration elapsedTime =
Duration.between(timeOfLastButtonPress, Instant.now());
laserOnTimeTF.setText(String.format("%02d:%02d:%02d",
elapsedTime.toHours(),
elapsedTime.toMinutes() % 60,
elapsedTime.getSeconds() % 60));
}
});

Use TimeLine to trigger a void method every certain seconds JavaFX

Im trying to update a label every certain seconds, I tried using a normal Timer but since its in another thread it cannot make changes to the label, this is the Timer:
public void setTimer(Timer timer, int seconds, String userName, String content, VBox tabContent,ArrayList<Integer> countTweetsArray, Label statusLabel) {
TabContent tabContentObj = new TabContent();
timer.schedule(new TimerTask() {
#Override
public void run() {
setTweet(userName, content);
//tabContentObj.createStatusScreen(tabContent, countTweetsArray, remainingTweets);
System.out.println(content+" after "+seconds);
System.out.println("countTweetsArray: "+countTweetsArray.get(0));
statusLabel.setText(countTweetsArray.get(0).toString());
countTweetsArray.set(0, (countTweetsArray.get(0)+1));
tabContentObj.timersMap.put(userName, timer);
}
}, (seconds*1000));
}
I read that I can make periodic changes to a label using TimeLine but I cant understand how it works the keyvalues and the keyframes, Is there a way to just trigger a void method without any animation involved?

You can use the KeyFrame constructor that takes a Duration and an event handler:
Timeline timeline = new Timeline(
new KeyFrame(Duration.seconds(seconds), e -> {
// code to execute here...
})
);
timeline.play();
Update: if you need a button to stop it, you can do that with
Button button = new Button("Stop");
button.setOnAction(e -> timeline.stop());

Run java function every hour

I want to run a function every hour, to email users a hourly screenshot of their progress. I code set up to do so in a function called sendScreenshot()
How can I run this timer in the background to call the function sendScreenshot() every hour, while the rest of the program is running?
Here is my code:
public int onLoop() throws Exception{
if(getLocalPlayer().getHealth() == 0){
playerHasDied();
}
return Calculations.random(200, 300);
}
public void sendScreenShot() throws Exception{
Robot robot = new Robot();
BufferedImage screenshot = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
screenshotNumber = getNewestScreenshot();
fileName = new File("C:/Users/%username%/Dreambot/Screenshots/Screenshot" + screenshotNumber +".");
ImageIO.write(screenshot, "JPEG", fileName);
mail.setSubject("Your hourly progress on account " + accName);
mail.setBody("Here is your hourly progress report on account " + accName +". Progress is attached in this mail.");
mail.addAttachment(fileName.toString());
mail.setTo(reciepents);
mail.send();
}

Use a ScheduledExecutorService:
ScheduledExecutorService ses = Executors.newSingleThreadScheduledExecutor();
ses.scheduleAtFixedRate(new Runnable() {
#Override
public void run() {
sendScreenShot();
}
}, 0, 1, TimeUnit.HOURS);
Prefer using a ScheduledExecutorService over Timer:
Java Timer vs ExecutorService?

According to this article by Oracle, it's also possible to use the #Schedule annotation:
#Schedule(hour = "*")
public void doSomething() {
System.out.println("hello world");
}
For example, seconds and minutes can have values 0-59, hours 0-23, months 1-12.
Further options are also described there.

java's Timer works fine here.
http://docs.oracle.com/javase/6/docs/api/java/util/Timer.html
Timer t = new Timer();
t.scheduleAtFixedRate(new TimerTask() {
public void run() {
// ...
}
}, delay, 1 * 3600 * 1000); // 1 hour between calls

For this type of period execution, meaning every day or every hour, all you need is using a Timer like this :
public static void main(String[] args) throws InterruptedException {
Calendar today = Calendar.getInstance();
today.set(Calendar.HOUR_OF_DAY, 7);
today.set(Calendar.MINUTE, 45);
today.set(Calendar.SECOND, 0);
Timer timer = new Timer();
TimerTask task = new TimerTask() {
#Override
public void run() {
System.out.println("I am the timer");
}
};
// timer.schedule(task, today.getTime(), TimeUnit.MILLISECONDS.convert(1, TimeUnit.DAYS)); // period: 1 day
timer.schedule(task, today.getTime(), TimeUnit.MILLISECONDS.convert(5, TimeUnit.SECONDS)); // period: 5 seconds
}
this exemple will execute the timetask every 5 seconds from the current date and 7:45 am.
Good Luck.

while (true) {
DateTime d = new DateTime();
switch(d.getMinuteOfHour()) {
case 56:
runHourly();
break;
case 41:
if(d.getHourOfDay() == 2) {
runAt0241Daily();
}
break;
}
SUM.wait(59000);
}
How about this for something you can control and understand?

Making a stopwatch using timer for javafx

I actually have a video streaming application and I want to show the time for how much the two people have chatted with eachother. I have used Timer and TimerTask of java.util class but it gives error as "Not on FX application thread" which means I cant setText to a java fx component using swing thread. This is what I have tried so far:-
int timerx=0 //global variable
private void timer(){
/*SHOWING TIME PASSED*/
int x=0;
Timer timer = new Timer();
TimerTask timerTask = new TimerTask() {
#Override
public void run() {
System.out.println("working");
setTime();
}
};
timer.schedule(timerTask, 50, 50);
}
And updating the javafx Label as:-
private void setTime(){
timerx = timerx +1;
Platform.runLater(new Runnable(){
public void run(){
time.setText(String.valueOf((timerx)));
System.out.println(time.getText());
}
});
}
I think the main problem is javafx component not being able to update and be accessed from swing thread. I would be glad to get any kind of help.
Thank you

You can use something like this:
long timeStart = System.currentTimeMillis();
when the chat start and get how long two guys chatted with something like this:
long timePassed = System.currentTimeMillis() - timeStart;
This will get you how many millisecond have passed. If you want to get second divide it by 1000. Oh and if you want it on thread, just create a thread for this thingy..

ok thank you all for your answers. I solved my problem by running a thread and using algorithm that will show the time in 00:00:00 format which I wanted to make. Here is the code
private void startTime(){
if(timerStats==false)
{
timerStats = true;
timer = new Timer();
TimerTask timerTask = new TimerTask() {
#Override
public void run() {
System.out.println("working" + x);
timersec ++;
Platform.runLater(new Runnable(){
public void run(){
if (timersec == 60)
{
timersec = 0;
timermin++;
}
if (timermin == 60)
{
timermin = 0;
timerhr++;
}
String seconds = Integer.toString(timersec);
String minutes = Integer.toString(timermin);
String hours = Integer.toString(timerhr);
if (timersec <= 9)
{
seconds = "0" + Integer.toString(timersec);
}
if (timermin <= 9)
{
minutes = "0" + Integer.toString(timermin);
}
if (timerhr <= 9)
{
hours = "0" + Integer.toString(timerhr);
}
time.setText(hours + ":" + minutes +":"+ seconds);
System.out.println(time.getText());
}
});
}
};
timer.schedule(timerTask, 50, 50); //lastone is time, milli second
}
}
Thank you

Dynamic Clock in java

I want to implement a clock within my program to diusplay the date and time while the program is running. I have looked into the getCurrentTime() method and Timers but none of them seem to do what I would like.
The problem is I can get the current time when the program loads but it never updates. Any suggestions on something to look into would be greatly appreciated!

What you need to do is use Swing's Timer class.
Just have it run every second and update the clock with the current time.
Timer t = new Timer(1000, updateClockAction);
t.start();
This will cause the updateClockAction to fire once a second. It will run on the EDT.
You can make the updateClockAction similar to the following:
ActionListener updateClockAction = new ActionListener() {
public void actionPerformed(ActionEvent e) {
// Assumes clock is a custom component
yourClock.setTime(System.currentTimeMillis());
// OR
// Assumes clock is a JLabel
yourClock.setText(new Date().toString());
}
}
Because this updates the clock every second, the clock will be off by 999ms in a worse case scenario. To increase this to a worse case error margin of 99ms, you can increase the update frequency:
Timer t = new Timer(100, updateClockAction);

You have to update the text in a separate thread every second.
Ideally you should update swing component only in the EDT ( event dispatcher thread ) but, after I tried it on my machine, using Timer.scheduleAtFixRate gave me better results:
java.util.Timer http://img175.imageshack.us/img175/8876/capturadepantalla201006o.png
The javax.swing.Timer version was always about half second behind:
javax.swing.Timer http://img241.imageshack.us/img241/2599/capturadepantalla201006.png
I really don't know why.
Here's the full source:
package clock;
import javax.swing.*;
import java.util.*;
import java.text.SimpleDateFormat;
class Clock {
private final JLabel time = new JLabel();
private final SimpleDateFormat sdf = new SimpleDateFormat("hh:mm");
private int currentSecond;
private Calendar calendar;
public static void main( String [] args ) {
JFrame frame = new JFrame();
Clock clock = new Clock();
frame.add( clock.time );
frame.pack();
frame.setVisible( true );
clock.start();
}
private void reset(){
calendar = Calendar.getInstance();
currentSecond = calendar.get(Calendar.SECOND);
}
public void start(){
reset();
Timer timer = new Timer();
timer.scheduleAtFixedRate( new TimerTask(){
public void run(){
if( currentSecond == 60 ) {
reset();
}
time.setText( String.format("%s:%02d", sdf.format(calendar.getTime()), currentSecond ));
currentSecond++;
}
}, 0, 1000 );
}
}
Here's the modified source using javax.swing.Timer
public void start(){
reset();
Timer timer = new Timer(1000, new ActionListener(){
public void actionPerformed( ActionEvent e ) {
if( currentSecond == 60 ) {
reset();
}
time.setText( String.format("%s:%02d", sdf.format(calendar.getTime()), currentSecond ));
currentSecond++;
}
});
timer.start();
}
Probably I should change the way the string with the date is calculated, but I don't think that's the problem here
I have read, that, since Java 5 the recommended is: ScheduledExecutorService I leave you the task to implement it.

This sounds like you might have a conceptual problem. When you create a new java.util.Date object, it will be initialised to the current time. If you want to implement a clock, you could create a GUI component which constantly creates a new Date object and updates the display with the latest value.
One question you might have is how to repeatedly do something on a schedule? You could have an infinite loop that creates a new Date object then calls Thread.sleep(1000) so that it gets the latest time every second. A more elegant way to do this is to use a TimerTask. Typically, you do something like:
private class MyTimedTask extends TimerTask {
#Override
public void run() {
Date currentDate = new Date();
// Do something with currentDate such as write to a label
}
}
Then, to invoke it, you would do something like:
Timer myTimer = new Timer();
myTimer.schedule(new MyTimedTask (), 0, 1000); // Start immediately, repeat every 1000ms

public void start(){
reset();
ScheduledExecutorService worker = Executors.newScheduledThreadPool(3);
worker.scheduleAtFixedRate( new Runnable(){
public void run(){
if( currentSecond == 60 ) {
reset();
}
time.setText( String.format("%s:%02d", sdf.format(calendar.getTime()), currentSecond));
currentSecond++;
}
}, 0, 1000 ,TimeUnit.MILLISECONDS );
}

For those preferring an analog display: Analog Clock JApplet.

Note the method scheduleAtFixedRate is used here
// Current time label
final JLabel currentTimeLabel = new JLabel();
currentTimeLabel.setFont(new Font("Monospace", Font.PLAIN, 18));
currentTimeLabel.setHorizontalAlignment(JTextField.LEFT);
// Schedule a task for repainting the time
final Timer currentTimeTimer = new Timer();
TimerTask task = new TimerTask() {
#Override
public void run() {
currentTimeLabel.setText(TIME_FORMATTER.print(System.currentTimeMillis()));
}
};
currentTimeTimer.scheduleAtFixedRate(task, 0, 1000);

Timer timer = new Timer(1000, (ActionEvent e) -> {
DateTimeFormatter myTime = DateTimeFormatter.ofPattern("HH:mm:ss");
LocalDateTime now = LocalDateTime.now();
jLabel1.setText(String.valueOf(myTime.format(now)));
});
timer.setRepeats(true);
timer.start();