不断检查时间？

Question

所以我正在制作一个显示列车时间的小样本应用程序.现在JTable列车的显示不是动态的.我想要的是,每次都要检查时间,30 secs or minute桌子会消除"应该到达"的列车.然而,我被困在不断检查的时间部分.我已经创建了一个TimeChecker在后台运行的类,但它没有多大用处,因为当我将无限循环或线程放入我的JPanel类时,用户界面没有显示.

这是我的TimeChecker:

package controller;

import java.text.SimpleDateFormat;
import java.util.Calendar;

public class TimeChecker extends Thread {
    private String timeStamp;

    public String getTimeStamp() {
        return timeStamp;
    }

    public void run() {
        while(true) {
            try {
                Thread.sleep(2000);
                String dateStamp = new SimpleDateFormat(
                                "yyyyMMdd_HHmmss").format(
                                Calendar.getInstance().getTime());
                timeStamp = dateStamp.substring(9,13);
                System.out.println(timeStamp);
            } catch(InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

这是我的Panel类:

package view;

import java.awt.GridLayout;

import javax.swing.JPanel;
import javax.swing.JTabbedPane;

import controller.*;

public class Panel extends JPanel {
    /* JPanel containing the JTabbedPane stuff */
    JTabbedPane jtp = new JTabbedPane();
    TimeChecker tc = new TimeChecker();

    public Panel() {
        super(new GridLayout(1,0));
        Table t = new Table("Haymarket");
        jtp.add(t);
        jtp.setTitleAt(0, "Haymarket");
        add(jtp);
        tc.setDaemon(true);
        tc.start();
    }

    public void addTrain(String d, String c, String dep, String a) {
        /* 
         * Receives 4 parameters to control 
         * the new entry required for a train 
         */
        Table t = (Table) jtp.getComponentAt(jtp.getSelectedIndex());
        t.addTrain(d,c,dep,a);
    }

    public void addStation(String s) {
        /* 
         * Adds a station, after prompting the 
         * user for a station name 
         */
        jtp.add(new Table(s));
        jtp.setTitleAt(jtp.getTabCount()-1, s);
        jtp.setSelectedIndex(jtp.getTabCount()-1);
    }

    public void addStation(Table t) {
        jtp.add(t);
        jtp.setTitleAt(jtp.getTabCount()-1,t.getStation());
    }

    public void removeAllStations() {
        jtp.removeAll();
    }

    public void removeStation() {
        /* 
         * Removes currently selected station 
         */
        jtp.remove(jtp.getSelectedIndex());
    }

    public void removeTrain() {
        /* 
         * WIP: Removes a train 
         */
        Table t = (Table) jtp.getComponentAt(jtp.getSelectedIndex());
        t.removeTrain();
    }
}

Answer 1

听起来你想要javax.swing.Timer每30秒发射一次.

或者,在后台线程中使用计时器(例如,通过a ScheduledExecutorService) - 然后获取信息,仅在实际需要更新UI时获取所涉及的UI.