交通灯UI上的Javafx线程连接。如何同步线程?
我有一个模拟交通灯的JavaFXUI。我有三个线程用于每个灯,分别点亮各自的灯,同时关闭其他灯。我启动线程并使用join(),这样每个线程都可以在另一个线程启动之前点亮各自的灯 当我使用Thread.join()时,UI会冻结,但我知道线程正在正常运行,因为我放在线程中的测试字符串会执行,并在另一个线程执行之前等待适当的时间 守则如下— 主要方法交通灯UI上的Javafx线程连接。如何同步线程?,java,multithreading,javafx,java.util.concurrent,Java,Multithreading,Javafx,Java.util.concurrent,我有一个模拟交通灯的JavaFXUI。我有三个线程用于每个灯,分别点亮各自的灯,同时关闭其他灯。我启动线程并使用join(),这样每个线程都可以在另一个线程启动之前点亮各自的灯 当我使用Thread.join()时,UI会冻结,但我知道线程正在正常运行,因为我放在线程中的测试字符串会执行,并在另一个线程执行之前等待适当的时间 守则如下— 主要方法 public void start(Stage primaryStage) { lightBoard.setArcWidth(10);
public void start(Stage primaryStage) {
lightBoard.setArcWidth(10);
lightBoard.setArcHeight(10);
lightBoard.setFill(Color.DARKGREY);
circleGreen.setFill(Color.WHITE);
circleYellow.setFill(Color.WHITE);
circleRed.setFill(Color.WHITE);
Group group = new Group();
group.getChildren().addAll(lightBoard, circleGreen, circleYellow, circleRed);
BorderPane light = new BorderPane(group);
light.setPadding( new Insets(20, 20, 20, 20) );
GridPane layoutControls = new GridPane();
layoutControls.setAlignment(Pos.CENTER);
Button btnStart = new Button("Start");
Button btnStop = new Button("Stop");
layoutControls.add(btnStart, 0, 0);
layoutControls.add(btnStop, 1, 0);
BorderPane root = new BorderPane();
root.setCenter(light);
root.setBottom(layoutControls);
Scene scene = new Scene(root, 380, 250);
primaryStage.setTitle("Traffic Light Simulator");
primaryStage.setScene(scene);
primaryStage.show();
// create and start threads
Runnable lightGreen = new LightGreen();
Runnable lightYellow = new LightYellow();
Runnable lightRed = new LightRed();
Thread threadGreen = new Thread(lightGreen);
Thread threadYellow = new Thread(lightYellow);
Thread threadRed = new Thread(lightRed);
while(true){
threadGreen = new Thread(lightGreen);
threadGreen.start();
try{
threadGreen.join();
}
catch(Exception e){
}
threadYellow = new Thread(lightYellow);
threadYellow.start();
try{
threadYellow.join();
}
catch(Exception e){
}
threadRed = new Thread(lightRed);
threadRed.start();
try{
threadRed.join();
}
catch(Exception e){
}
}
}
螺纹等级-
class LightGreen implements Runnable {
@Override
public void run() {
lock.lock();
System.out.println("GREEn");
circleGreen.setFill( Color.GREEN );
circleYellow.setFill( Color.WHITE );
circleRed.setFill( Color.WHITE );
lock.unlock();
try {
Thread.sleep(3000L);
} catch (InterruptedException ex) {
}
}
}
class LightYellow implements Runnable {
@Override
public void run() {
lock.lock();
System.out.println("YELLOW");
circleGreen.setFill( Color.WHITE );
circleYellow.setFill( Color.YELLOW );
circleRed.setFill( Color.WHITE );
lock.unlock();
try {
Thread.sleep(3000L);
} catch (InterruptedException ex) {
}
}
}
class LightRed implements Runnable {
@Override
public void run() {
lock.lock();
System.out.println("RED");
circleGreen.setFill( Color.WHITE );
circleYellow.setFill( Color.WHITE );
circleRed.setFill( Color.RED );
lock.unlock();
try {
Thread.sleep(3000L);
} catch (InterruptedException ex) {
}
}
}
我如何解决这个问题?我被告知可以使用Platform.runlater,但不确定如何使用它。我需要使用多线程来完成此任务。下面是如何使用JavaFx更新gui的快速演示:
public class TrafficLight extends Application{
private static final double RADIUS = 50;
private static final double PAUSE = 1;
private Circle circleRed, circleYellow, circleGreen;
private Color[] colors = {Color.RED, Color.YELLOW, Color.GREEN};
private int onColor = 0;
@Override
public void start(Stage primaryStage) {
circleRed = new Circle(RADIUS);
circleRed.setFill(Color.WHITE);
circleGreen = new Circle(RADIUS);
circleGreen.setFill(Color.WHITE);
circleYellow = new Circle(RADIUS);
circleYellow.setFill(Color.WHITE);
TilePane light = new TilePane(circleGreen, circleYellow, circleRed);
light.setPadding( new Insets(20, 20, 20, 20) );
Scene scene = new Scene(light, RADIUS*8, RADIUS*3);
primaryStage.setTitle("Traffic Light Simulator");
primaryStage.setScene(scene);
primaryStage.show();
update();
}
private void update() {
PauseTransition pause = new PauseTransition(Duration.seconds(PAUSE));
pause.setOnFinished(event ->{
circleRed.setFill((onColor == 0) ? colors[onColor] :Color.WHITE );
circleYellow.setFill((onColor == 1) ? colors[onColor] :Color.WHITE);
circleGreen.setFill((onColor == 2) ? colors[onColor] :Color.WHITE);
onColor = ((onColor +1) >= colors.length) ? 0 : onColor+1;
pause.play();
});
pause.play();
}
public static void main(String[] args) {
launch(args);
}
}
编辑如果您需要使用线程,尽管我认为它不是最佳工具,但请尝试以下技术:
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.layout.TilePane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
public class TrafficLight extends Application{
private static final double RADIUS = 50;
private Circle circleRed, circleYellow, circleGreen;
private Color[] colors = {Color.RED, Color.YELLOW, Color.GREEN};
private int onColor = 0;
private static int threadNumber = 0, invokeThreadNumber =0;
private static final Object myLock = new Object();
@Override
public void start(Stage primaryStage) {
circleRed = new Circle(RADIUS);
circleRed.setFill(Color.WHITE);
circleGreen = new Circle(RADIUS);
circleGreen.setFill(Color.WHITE);
circleYellow = new Circle(RADIUS);
circleYellow.setFill(Color.WHITE);
TilePane light = new TilePane(circleGreen, circleYellow, circleRed);
light.setPadding( new Insets(20, 20, 20, 20) );
Scene scene = new Scene(light, RADIUS*8, RADIUS*3);
primaryStage.setTitle("Traffic Light Simulator");
primaryStage.setScene(scene);
primaryStage.show();
control();
}
private void control() {
//invoke 3 synchronized control threads
new Thread( new ColorControl()).start();
new Thread( new ColorControl()).start();
new Thread( new ColorControl()).start();
}
private void update() {
circleRed.setFill((onColor == 0) ? colors[onColor] :Color.WHITE );
circleYellow.setFill((onColor == 1) ? colors[onColor] :Color.WHITE);
circleGreen.setFill((onColor == 2) ? colors[onColor] :Color.WHITE);
onColor = ((onColor +1) >= colors.length) ? 0 : onColor+1;
}
class ColorControl implements Runnable {
private int threadID;
private static final long PAUSE = 1000;
private int MAX_THREADS = 3;
private boolean isStopped = false;
ColorControl() {
threadID = threadNumber ++;
}
void reset() {
threadNumber = 0; invokeThreadNumber =0;
}
@Override
public void run() {
synchronized (myLock) {
while (! isStopped ) {
while (threadID != invokeThreadNumber) {
try {
myLock.wait();
} catch (InterruptedException e) {}
}
//do work here
update();
try {
Thread.sleep(PAUSE);
} catch (InterruptedException ex) { ex.printStackTrace();}
invokeThreadNumber++;
myLock.notifyAll();
if( invokeThreadNumber >= MAX_THREADS ) {
reset();
}
}
}
}
}
public static void main(String[] args) {
launch(args);
}
}
您可能需要添加所有代码,以便可以尝试查看发生了什么。请不要添加所有代码。更好的POST考虑使用JavaFX或IM尝试使用线程来完成它。也许我应该在帖子里提一下。我想你的问题是你从一开始就没有回来过()。最后被困在无限的while循环中。这将变得复杂-但您可以从将while的内部拉入一个助手方法开始,该方法使用start()中的Platform.runLater()调用。然后在该helper方法的末尾,再次使用Platform.runLater调用它。这模拟了您的while(true),但将执行移动到以后,允许start()返回,将控制权返回到JavaFX…谢谢,它可以工作,但我需要使用多线程,因为我正在学习多线程。谢谢,它可以工作。我将尝试更多地使用多线程。