定期刷新数据 [英] Periodically refresh data
本文介绍了定期刷新数据的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想定期显示数据，但是当我尝试显示数据时出现错误。
I want to display data periodically but I get error when I try to display the data.
Timeline fiveSecondsWonder = new Timeline(new KeyFrame(Duration.seconds(3), new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent event) {
GridPane gp = new GridPane();
gp.setPadding(new Insets(10, 10, 10, 10));
gp.setHgap(20);
gp.setVgap(10);
//gp.setGridLinesVisible(true);
gp.add(new Label("Operating System Name"), 0, 0);
gp.add(new Label(System.getProperty("os.name")), 1, 0);
gp.add(new Label("Operating System Version"), 0, 1);
gp.add(new Label(System.getProperty("os.version")), 1, 1);
gp.add(new Label("System Architecture"), 0, 2);
gp.add(new Label(System.getProperty("os.arch")), 1, 2);
gp.add(new Label("Total Memory"), 0, 3);
String memStrLong = Long.toString(Runtime.getRuntime().totalMemory());
gp.add(new Label(memStrLong), 1, 3);
gp.add(new Label("Used Memory"), 0, 4);
String fStrLong = Long.toString(Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory());
gp.add(new Label(fStrLong), 1, 4);
gp.add(new Label("Java Version"), 0, 5);
gp.add(new Label(System.getProperty("java.version")), 1, 5);
gp.add(new Label("Number of Processors"), 0, 6);
String pStrLong = Long.toString(Runtime.getRuntime().availableProcessors());
gp.add(new Label(pStrLong), 1, 6);
gp.add(new Label("Maximum available Memory"), 0, 7);
String amStrLong = Long.toString(Runtime.getRuntime().maxMemory());
gp.add(new Label(amStrLong), 1, 7);
}
}));
fiveSecondsWonder.setCycleCount(Timeline.INDEFINITE);
fiveSecondsWonder.play();
Vbox.getChildren().add(gp);
你能帮我正确实施这个例子吗？
Can you help me to implement properly this example, please?
编辑：第二次测试：
ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread thread = new Thread(r);
thread.setDaemon(true);
return thread;
}
});
scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
final GridPane gp = new GridPane();
@Override
public void run() {
gp.getChildren().clear();
gp.setPadding(new Insets(10, 10, 10, 10));
gp.setHgap(20);
gp.setVgap(10);
//gp.setGridLinesVisible(true);
gp.add(new Label("Operating System Name"), 0, 0);
gp.add(new Label(System.getProperty("os.name")), 1, 0);
gp.add(new Label("Operating System Version"), 0, 1);
gp.add(new Label(System.getProperty("os.version")), 1, 1);
gp.add(new Label("System Architecture"), 0, 2);
gp.add(new Label(System.getProperty("os.arch")), 1, 2);
gp.add(new Label("Total Memory"), 0, 3);
String memStrLong = Long.toString(Runtime.getRuntime().totalMemory());
gp.add(new Label(memStrLong), 1, 3);
gp.add(new Label("Used Memory"), 0, 4);
String fStrLong = Long.toString(Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory());
gp.add(new Label(fStrLong), 1, 4);
gp.add(new Label("Java Version"), 0, 5);
gp.add(new Label(System.getProperty("java.version")), 1, 5);
gp.add(new Label("Number of Processors"), 0, 6);
String pStrLong = Long.toString(Runtime.getRuntime().availableProcessors());
gp.add(new Label(pStrLong), 1, 6);
gp.add(new Label("Maximum available Memory"), 0, 7);
String amStrLong = Long.toString(Runtime.getRuntime().maxMemory());
gp.add(new Label(amStrLong), 1, 7);
vb.getChildren().add(gp);
}
}, 0, 1, TimeUnit.SECONDS);
我也对此进行了测试，但数据未更新。
I also tested this but with the data is not updated.
推荐答案
public class Sandbox extends Application {
private final StringProperty totalMemoryProperty = new SimpleStringProperty();
private final StringProperty usedMemoryProperty = new SimpleStringProperty();
private final StringProperty maxMemoryProperty = new SimpleStringProperty();
public static void main(final String[] args) throws Exception {
launch(args);
}
@Override
public void start(final Stage stage) throws Exception {
final GridPane gp = new GridPane();
gp.setPadding(new Insets(10, 10, 10, 10));
gp.setHgap(20);
gp.setVgap(10);
gp.add(new Label("Operating System Name"), 0, 0);
gp.add(new Label(System.getProperty("os.name")), 1, 0);
gp.add(new Label("Operating System Version"), 0, 1);
gp.add(new Label(System.getProperty("os.version")), 1, 1);
gp.add(new Label("System Architecture"), 0, 2);
gp.add(new Label(System.getProperty("os.arch")), 1, 2);
gp.add(new Label("Java Version"), 0, 5);
gp.add(new Label(System.getProperty("java.version")), 1, 5);
gp.add(new Label("Number of Processors"), 0, 6);
String pStrLong = Long.toString(Runtime.getRuntime().availableProcessors());
gp.add(new Label(pStrLong), 1, 6);
gp.add(new Label("Total Memory"), 0, 3);
gp.add(new Label("Used Memory"), 0, 4);
gp.add(new Label("Maximum available Memory"), 0, 7);
final Label totalMemoryLabel = new Label();
totalMemoryLabel.textProperty().bind(totalMemoryProperty);
gp.add(totalMemoryLabel, 1, 3);
final Label usedMemoryLabel = new Label();
usedMemoryLabel.textProperty().bind(usedMemoryProperty);
gp.add(usedMemoryLabel, 1, 4);
final Label maxMemoryLabel = new Label();
maxMemoryLabel.textProperty().bind(maxMemoryProperty);
gp.add(maxMemoryLabel, 1, 7);
final VBox rootNode = new VBox();
rootNode.getChildren().add(gp);
ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread thread = new Thread(r);
thread.setDaemon(true);
return thread;
}
});
scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
final Runnable runnable = new Runnable() {
@Override
public void run() {
String memStrLong = Long.toString(Runtime.getRuntime().totalMemory());
totalMemoryProperty.setValue(memStrLong);
String fStrLong = Long.toString(Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory());
usedMemoryProperty.setValue(fStrLong);
String amStrLong = Long.toString(Runtime.getRuntime().maxMemory());
maxMemoryProperty.setValue(amStrLong);
}
};
Platform.runLater(runnable);
}
}, 0, 1, TimeUnit.SECONDS);
final Scene scene = new Scene(rootNode, 1024, 768);
stage.setScene(scene);
stage.show();
}
}
我使用数据绑定工作，使用Platform.runLater（）返回GUI线程来更新javafx组件。
I made your code work with databinding, use Platform.runLater() to go back to the GUI thread to update javafx components.
如果你想使用ScheduledService，这是一个基本的例子：
If you want to use ScheduledService here is a basic example:
public class Sandbox extends Application {
public static void main(final String[] args) throws Exception {
launch(args);
}
class MyService extends ScheduledService<List<String>> {
@Override
protected Task<List<String>> createTask() {
final Task<List<String>> voidTask = new Task<List<String>>() {
@Override
protected List<String> call() throws Exception {
List<String> results = new ArrayList<>();
final String memStrLong = Long.toString(Runtime.getRuntime().totalMemory());
results.add(memStrLong);
final String fStrLong = Long.toString(Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory());
results.add(fStrLong);
final String amStrLong = Long.toString(Runtime.getRuntime().maxMemory());
results.add(amStrLong);
return results;
}
};
return voidTask;
}
}
@Override
public void start(final Stage stage) throws Exception {
final GridPane gp = new GridPane();
gp.setPadding(new Insets(10, 10, 10, 10));
gp.setHgap(20);
gp.setVgap(10);
gp.add(new Label("Operating System Name"), 0, 0);
gp.add(new Label(System.getProperty("os.name")), 1, 0);
gp.add(new Label("Operating System Version"), 0, 1);
gp.add(new Label(System.getProperty("os.version")), 1, 1);
gp.add(new Label("System Architecture"), 0, 2);
gp.add(new Label(System.getProperty("os.arch")), 1, 2);
gp.add(new Label("Java Version"), 0, 5);
gp.add(new Label(System.getProperty("java.version")), 1, 5);
gp.add(new Label("Number of Processors"), 0, 6);
final String pStrLong = Long.toString(Runtime.getRuntime().availableProcessors());
gp.add(new Label(pStrLong), 1, 6);
gp.add(new Label("Total Memory"), 0, 3);
gp.add(new Label("Used Memory"), 0, 4);
gp.add(new Label("Maximum available Memory"), 0, 7);
final Label totalMemoryLabel = new Label();
gp.add(totalMemoryLabel, 1, 3);
final Label usedMemoryLabel = new Label();
gp.add(usedMemoryLabel, 1, 4);
final Label maxMemoryLabel = new Label();
gp.add(maxMemoryLabel, 1, 7);
final VBox rootNode = new VBox();
rootNode.getChildren().add(gp);
final MyService service = new MyService();
service.setDelay(new Duration(300));
service.setPeriod(new Duration(1000));
service.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
@Override
public void handle(final WorkerStateEvent workerStateEvent) {
List<String> results = (List<String>) workerStateEvent.getSource().getValue();
totalMemoryLabel.setText(results.get(0));
usedMemoryLabel.setText(results.get(1));
maxMemoryLabel.setText(results.get(2));
}
});
service.start();
final Scene scene = new Scene(rootNode, 1024, 768);
stage.setScene(scene);
stage.show();
}
}
这篇关于定期刷新数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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