Definition of JavaFX Timer
JavaFX is known for its flexibility and easiness. There are several classes available in it and Timer is a class that helps in scheduling the tasks that has to be executed later. The creation of a new object of Timer spawns a thread that is new that can execute the program after a mentioned amount of time. This can help the developer to mention if the timer has to be run at a repeated interval or only once. Timer in JavaFx is denoted by the java.util.Timer class. Let us see more about this topic in the following sections.
Syntax:
Following is the syntax of JavaFX timer.
Timer timerobj = new Timer();How to Create a Timer in JavaFX?
Similar to Timer class, the TimerTask class has a role in the execution of timer. It is an abstract class that extends the interface Runnable. However, it does not implement the method run. Moreover, a subclass of the class TimerTask can be created that can override the method run during the time when the timer fires within the overridden method run. For putting this all together, a subclass instance can be passed to Timer.schedule. Otherwise, an anonymous class can also be passed to Timer.schedule.
Examples
Now, let us see some sample examples on JavaFX timer.
Example #1: Demonstrate the working of a timer with the help of a button
Code:
//import all the relevant classes
import java.util.Timer;
import java.util.TimerTask;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.Spinner;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
//main class
public class TimerProgramSample extends Application
{
//set the delay as 0
int del = 0;
public void start(Stage st) {
UIinitialisation(st);
}
private void UIinitialisation(Stage st) {
//create object for horizantal box
HBox hb = new HBox(12);
//set the padding
hb.setPadding(new Insets(12));
//create object for timer class
Timer tm = new java.util.Timer();
//create object for spinner class
Spinner sp = new Spinner(1, 62, 5);
//set the prefernce width
sp.setPrefWidth(85);
//create button
Button b = new Button("Yayyy. . . Timer works. . .");
//set the action event on clicking the button
b.setOnAction(event -> {
del = (int) sp.getValue();
//schedule the timer
tm.schedule(new subtimer(), del*1000);
});
//get the children of horizontal box
hb.getChildren().addAll(b, sp);
//on close event
st.setOnCloseRequest(event -> {
tm.cancel();
});
//create a scene
Scene sc = new Scene(hb);
//set the title
st.setTitle("Timer Working");
//set the scene
st.setScene(sc);
//display the result
st.show();
}
//subclass that extends the TimerTask
private class subtimer extends TimerTask {
//run method
@Override
public void run() {
//method
Platform.runLater(() -> {
//create object for Alert class
Alert al = new Alert(Alert.AlertType.INFORMATION);
//set the title
al.setTitle("Dialog box");
//set the header text
al.setHeaderText("Oh oh.. Time elapsed");
//create a string
String c;
//check the condition of delay
if (del == 1) {
// display one second is elapsed
c = "1 sec elapsed";
} else
{
c = String.format("%d sec elapsed",
del);
}
al.setContentText(c);
al.showAndWait();
});
}
}
//main method
public static void main(String[] args) {
//launch the app
launch(args);
}
}Output:
In this program, all the necessary classes have to be imported. Then, set the delay as 0. Once this is completed, call the method UIinitialisation as it contains the whole functionalities we have to implement. In that method, create an object for the horizontal box. Then set the padding of the horizontal box. Once this is done, the timer class object and spinner class object can be created. After that, set the preferred width and create the button. As we all know, if a button is created, we have to implement the action event of the same. That is, the functionality that has to trigger on clicking the button has to be mentioned. Here, the delay value is retrieved and the timer is scheduled based on the subclass sub timer that extends the TimerTask. That function gets called which contains the overridden run method. After getting out of the subclass, a scene object can be created, followed by setting the title, scene, and displaying the result.
On executing the code, a dialog box will appear as shown above. As I have selected 5 seconds and clicked the button, a dialog box as shown below appears after every five seconds.
Once we change the value to another value, it will be displayed as displayed below. That is, timer functions for the new value given
Example #2: Demonstrate the working of Timer
Code:
//import all the relevant classes
import java.util.Timer;
import java.util.TimerTask;
//main class
public class TimerProgramSample {
//main method
public static void main(String[] args) {
//notify that timer starts
System.out.println("Here, it starts....");
//create object for timer
Timer tm = new Timer();
//schedule the timer
tm.schedule(new TimerTask(){
//override run method
@Override
public void run() {
//print a message notifying about timer
System.out.println("Timer begins. . . .");
}
}, 5000);
//tIMER that repeats each 20second
Timer tr = new Timer() ;
//schedule the repeating timer
tr.scheduleAtFixedRate(new TimerTask(){
//override run methid
@Override
public void run(){
System.out.println("Timer working. . . .");
}
}, 0, 2000);
}
}Output:
In this program also, all the necessary classes have to be imported. Then, create an object for the timer and schedule it. Override the run method and print a message notifying about the timer. Once this is done, a repeating timer is also set. Similar to the first one, it also has to be scheduler and override the run method. On executing the code, the result will be displayed as shown above. As this is a repeating timer, it can be stopped by clicking the red square box that terminates the same.
Conclusion
In JavaFX, Timer is a class that helps in scheduling the tasks that have to be executed later. Timer in JavaFx is denoted by the java.util.Timer class. In this article, different details on JavaFX timer such as working and examples are discussed in detail.
Recommended Articles
This is a guide to JavaFX Timer. Here we discuss the definition and How to Create a Timer in JavaFX? along with examples. You may also have a look at the following articles to learn more –
