java - 自动更新JTable

Question

JTable 如何根据时间自动更新？因此，每次当前时间发生变化时，该表都会自动更新。有人可以提供一段代码来说明这在 Java 中如何工作吗？时间更改后更新表。请提前感谢您。

          package times;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;

public class TableTimeChange {

DefaultTableModel model2 = new DefaultTableModel();

String rowdata[] = new String[8];
Date[] date123 = new Date[8];

private SimpleDateFormat format = new SimpleDateFormat("HH:mm:dd:ss");
private JTable table = new JTable(getTableModel());

public TableTimeChange() {
    table.setPreferredScrollableViewportSize(table.getPreferredSize());
    JFrame frame = new JFrame();
    frame.add(new JScrollPane(table));
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.pack();

    Timer timer = new Timer(1000, new TimerListener());
    timer.start();
    frame.setVisible(true);
}

private TableModel getTableModel() {
    String[] cols = {"Time"};


    String array1[] = { "12-12-2001 10:18:30 PM", "12-15-2001 10:18:54 PM"};
    String array2[] = {"01-19-1989 01:18:27 AM", "01-19-2019 01:28:36 PM"};
    String array3[] = {"12-05-1989 05:18:57 PM", "08-25-1989 09:18:27 PM"};
    String array4[] = { "10-15-1985 09:18:17 AM", "10-25-1985 06:48:27 AM"};
    String array5[] = {"06-10-2001 03:09:19 AM", "05-16-2011 03:29:10 AM"};
    String array6[] = {"01-12-2000 09:00:08 PM", "11-22-2010 07:00:56 PM"};
    String array7[] = { "07-19-1969 12:18:47 PM", "02-05-1969 01:18:17 AM"};
    String array8[] = {"01-09-2010 10:09:50 AM", "12-09-2010 05:09:10 PM"};


    rowdata[0] = array1[0];
    rowdata[1] = array2[0];
    rowdata[2] = array3[0];
    rowdata[3] = array4[0];
    rowdata[4] = array5[0];
    rowdata[5] = array6[0];
    rowdata[6] = array7[0];
    rowdata[7] = array8[0];


    for(int t = 0; t<rowdata.length; t++)
    {

        DateFormat sdf = new SimpleDateFormat("MM-dd-yyyy hh:mm:ss a");
        DateFormat sdf3 = new SimpleDateFormat("MM-dd-yyyy hh:mm:ss a");


        try {

            date123[t] = sdf.parse(rowdata[t]);


        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    for(int i = 0; i<8; i++)
    {



    String[][] data = {{getFormatDate(date123[i])},{ getFormatDate(date123[i])}};
    DefaultTableModel model = new DefaultTableModel(data, cols);

   model2 = model;


    }


    return model2;
}

private String getFormatDate(Date date) {
    return format.format(date);
}

private class TimerListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        DefaultTableModel model = (DefaultTableModel)table.getModel();
        for (int i = model.getRowCount() -1; i >= 0; i--) {
            model.setValueAt(getFormatDate(date123[i]), i, 0);
        }   
    }
}

public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            new TableTimeChange();
        }
    });
}
}

Answer 1

只需使用 Swing Timer，就像我在评论中提到的那样。您需要为 Timer 提供一个 ActionListener，其中的 actionPerformed 将每隔几毫秒调用一次(无论您提供什么作为第一个参数)在构造函数中)。在那里，您将使用新的 Date 或格式化日期更新表模型(正如我在下面的示例中所做的那样)，并根据该日期更改表中的任何数据。

查看更多信息 How to Use Swing Timers

_{免责声明:我实在是太不适应了。我到底为什么在格式中使用 dd ？那不应该在那里。它应该是“HH:mm:ss”。我懒得改了。}

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;

public class TableTimeChange {

    private SimpleDateFormat format = new SimpleDateFormat("HH:mm:dd:ss");
    private JTable table = new JTable(getTableModel());

    public TableTimeChange() {
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JFrame frame = new JFrame();
        frame.add(new JScrollPane(table));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();

        Timer timer = new Timer(1000, new TimerListener());
        timer.start();
        frame.setVisible(true);
    }

    private TableModel getTableModel() {
        String[] cols = {"Time", "Is Seconds Even"};
        Object[][] data = { { getNewRow() }, { getNewRow() } };
        DefaultTableModel model = new DefaultTableModel(data, cols);
        return model;
    }

    private String getFormatDate(Date date) {
        return format.format(date);
    }

    private Object[] getNewRow() {
        Calendar cal = Calendar.getInstance();
        int seconds = cal.get(Calendar.SECOND);
        boolean isSecondsEven = (seconds % 2 == 0);
        return new Object[] { getFormatDate(cal.getTime()), isSecondsEven };
    }

    private class TimerListener implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            DefaultTableModel model = (DefaultTableModel)table.getModel();
            for (int i = model.getRowCount() -1; i >= 0; i--) {
                Object[] row = getNewRow();
                model.setValueAt(row[0], i, 0);
                model.setValueAt(row[1], i, 1);
            }   
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new TableTimeChange();
            }
        });
    }
}