所以标题真的说明了一切。 在执行方法中的下一个命令之前,我需要线程等待计时器完成。
代码:
import javax.swing.Timer;
public class doesntMatter
{
Timer timer;
ActionListener timerTask;
public doesntMatter
{
timerTask = new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
//taskSomethingIdk
}
}
}
private void whatever
{
timer = new Timer(1000, timerTask);
timer.setInitialDelay(0);
timer.start();
// here i need to wait for the timer to finish
if(timerhasfrigginfinished)
continueOrSomethingIdk
}
}
答案 0 :(得分:1)
假设您的计时器重复,在Timer的ActionListener内部检查它是否正在运行其最后一次重复,如果是,那里,请调用continueOrSomethingIdk()
方法。
否则您将不得不设置自己的通知机制,即回调,以便计时器通知任何听众已完成运行。
例如:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
@SuppressWarnings("serial")
public class WhenTimerDone extends JPanel {
private static final Color[] COLORS = {
Color.RED, Color.ORANGE,
Color.YELLOW, Color.GREEN,
Color.BLUE, Color.CYAN };
private static final String START = "Start";
private static final String DONE = "Done";
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
public static final int TIMER_DELAY = 1000;
private JLabel statusLabel = new JLabel(START);
private StartAction startAction = new StartAction("Start!");
public WhenTimerDone() {
add(statusLabel);
add(new JButton(startAction));
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
// this is the method called by the Timer's ActionListener when it is done
public void done() {
// reset all to baseline state
statusLabel.setText(DONE);
startAction.setEnabled(true);
setBackground(null);
}
// ActionListener for the start button
private class StartAction extends AbstractAction {
public StartAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
@Override
public void actionPerformed(ActionEvent e) {
// disables itself
setEnabled(false);
statusLabel.setText(START); // updates the status label
// create and start a timer
Timer timer = new Timer(TIMER_DELAY, new TimerListener());
timer.setInitialDelay(0);
timer.start();
}
}
// action listener for the timer
private class TimerListener implements ActionListener {
private int colorsIndex = 0;
@Override
public void actionPerformed(ActionEvent e) {
// simply loops through a colors array, changing background color
if (colorsIndex < COLORS.length) {
setBackground(COLORS[colorsIndex]);
colorsIndex++;
} else {
// when all colors shown -- stop the timer
((Timer) e.getSource()).stop();
// and call the done method -- ******* here's the key!
done(); // called when Timer is done!
}
}
}
private static void createAndShowGui() {
WhenTimerDone mainPanel = new WhenTimerDone();
JFrame frame = new JFrame("WhenTimerDone");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
答案 1 :(得分:0)
这里的关键字是通知/等待 您的计时器线程应该通知应该等待的其他线程 像这样:
import javax.swing.Timer;
public class doesntMatter
{
Timer timer;
ActionListener timerTask;
public doesntMatter
{
timerTask = new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
synchronized(timer){
//taskSomethingIdk
//you would have to rig something so we can access a common object as the monitor/lock object
timer.notify()
}
}
}
}
private void whatever
{
timer = new Timer(1000, timerTask);
timer.setInitialDelay(0);
timer.start();
//Need to obtain a lock on the "monitor" object
//Lock will be released while it is waiting
synchronized(timer){
timer.wait()
//do whatever
}
}
}
这将使“主”线程等到定时器线程调用notify方法,然后唤醒其中一个等待线程。
此外,我不认为“ActionListener”扩展了“TimerTask”。因此,代码示例可能无法编译,因为您向Timer提供了一个ActionListener,它希望TimerTask作为输入。或者也许我不知道你的代码应该做什么。
有关详细信息,请参阅How to use wait and notify in Java?。