如何在java中的JTextField中停止输入后启动一个函数

如何在JTextField中停止输入后启动一个函数。 不是每个关键版本。 如果两个键释放时间差大于1秒，则它将运行此function。 否则等待1秒钟。

Answer 1

使用Swing Timer和DocumentListener ，每次更新Document ，重置Timer

有关详细信息，请查看如何使用Swing Timers和Listening for Document对文档进行更改

作为一个简单的例子……

 import java.awt.EventQueue; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.FocusEvent; import java.awt.event.FocusListener; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.Timer; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; public class Test { public static void main(String[] args) { new Test(); } public Test() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { ex.printStackTrace(); } JFrame frame = new JFrame("Testing"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(new TestPane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class TestPane extends JPanel { public TestPane() { JTextField field = new JTextField(20); JLabel label = new JLabel("Waiting"); DeferredDocumentListener listener = new DeferredDocumentListener(1000, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // Execute your required functionality here... label.setText(label.getText() + "."); } }, true); field.getDocument().addDocumentListener(listener); field.addFocusListener(new FocusListener() { @Override public void focusGained(FocusEvent e) { listener.start(); } @Override public void focusLost(FocusEvent e) { listener.stop(); } }); setLayout(new GridBagLayout()); GridBagConstraints gbc = new GridBagConstraints(); gbc.gridwidth = GridBagConstraints.REMAINDER; add(field, gbc); add(label, gbc); } } public class DeferredDocumentListener implements DocumentListener { private final Timer timer; public DeferredDocumentListener(int timeOut, ActionListener listener, boolean repeats) { timer = new Timer(timeOut, listener); timer.setRepeats(repeats); } public void start() { timer.start(); } public void stop() { timer.stop(); } @Override public void insertUpdate(DocumentEvent e) { timer.restart(); } @Override public void removeUpdate(DocumentEvent e) { timer.restart(); } @Override public void changedUpdate(DocumentEvent e) { timer.restart(); } } } 

Answer 2

如果您不介意使用两个库，使用RxSwing和RxJava可以很容易地解决这个问题：

  EventQueue.invokeLater(() -> { try { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); frame.getContentPane().setLayout(new BorderLayout()); JTextField textField = new JTextField(30); frame.getContentPane().add(textField, BorderLayout.NORTH); // HERE SwingObservable.fromDocumentEvents(textField.getDocument()) .debounce(1, TimeUnit.SECONDS) .map(documentEvent -> textField.getText()) .subscribe(System.out::println); frame.setVisible(true); frame.pack(); } catch (final Exception e) { e.printStackTrace(); } });