JSpinner的表示時間具有恆定小時儘管正確值

Question

偏移我已在下面的代碼段，其假定在JSpinner的對象以顯示時間

Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT")); 

cal.set(Calendar.HOUR_OF_DAY, 0); 
cal.set(Calendar.AM_PM, 0); 
cal.set(Calendar.HOUR, 0); 
cal.set(Calendar.MINUTE, 0); 
cal.set(Calendar.SECOND, 0); 
cal.set(Calendar.MILLISECOND, 0); 

spStartTime = new JSpinner(new CustomSpinnerModel(cal.getTime(), null, null, cal.get(Calendar.HOUR_OF_DAY), 100, "start")); 

((JSpinner.DefaultEditor) spStartTime.getEditor()).getTextField().setFormatterFactory(new DefaultFormatterFactory(new DateFormatter(new SimpleDateFormat("hh:mm:ss,SSS")))); 

CustomSpinnerModel延伸SpinnerDateModel和我重寫getNextValue（）和getPreviousValue（） 。

public Object getNextValue() 
{ 
    Object next = super.getValue(); 
    Calendar calendar = new GregorianCalendar(); 

    calendar.setTimeZone(TimeZone.getTimeZone("GMT")); 
    calendar.setTime((Date) next); 

    Date helper = new Date(calendar.getTimeInMillis() + defaultStep); 

    calendar.setTime(helper); 

    System.out.println(calendar.getTimeInMillis()); 
    return calendar.getTime(); 
} 

現在這個打印100毫秒我第一次打上箭頭，這意味着值是正確的，因爲我開始0毫秒。問題是，我在JSpinner中看到的是

02:00:00,100 

可視化中存在一個持續2小時的偏移量。

Answer 1

我覺得DateFormat#setTimeZone(TimeZone)是你在找什麼：

//((JSpinner.DefaultEditor) spStartTime.getEditor()).getTextField() 
// .setFormatterFactory(new DefaultFormatterFactory(
// new DateFormatter(new SimpleDateFormat("hh:mm:ss,SSS")))); 
SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss,SSS"); 
format.setTimeZone(TimeZone.getTimeZone("GMT")); 
((JSpinner.DefaultEditor) spStartTime.getEditor()).getTextField() 
    .setFormatterFactory(new DefaultFormatterFactory(
     new DateFormatter(format))); 

import java.awt.*; 
import java.text.*; 
import java.util.*; 
import javax.swing.*; 
import javax.swing.text.*; 

public class DateEditorTimeZoneTest { 
    public JComponent makeUI() { 
    SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss,SSS"); 
    format.setTimeZone(TimeZone.getTimeZone("GMT")); 

    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT")); 
    cal.clear(Calendar.HOUR_OF_DAY); 
    cal.clear(Calendar.AM_PM); 
    cal.clear(Calendar.HOUR); 
    cal.clear(Calendar.MINUTE); 
    cal.clear(Calendar.SECOND); 
    cal.clear(Calendar.MILLISECOND); 

    Date start = cal.getTime(); 
    System.out.println(start); 
    System.out.println(format.format(start)); 

    int defaultStep = 100; 
    JSpinner spinner = new JSpinner(new SpinnerDateModel(
      start, null, null, Calendar.MILLISECOND) { 
     @Override public void setCalendarField(int calendarField) { 
     // If you only want one field to spin you can subclass 
     // and ignore the setCalendarField calls. 
     } 
     @Override public Object getNextValue() { 
     Object next = super.getValue(); 
     Calendar calendar = new GregorianCalendar(); 
     calendar.setTimeZone(TimeZone.getTimeZone("GMT")); 
     calendar.setTime((Date) next); 
     Date helper = new Date(calendar.getTimeInMillis() + defaultStep); 
     calendar.setTime(helper); 
     System.out.println(calendar.getTimeInMillis()); 
     return calendar.getTime(); 
     } 
     //@Override public Object getPreviousValue() { 
     // //... 
     //} 
    }); 
    JSpinner.DateEditor editor = new JSpinner.DateEditor(spinner, "HH:mm:ss,SSS"); 
    spinner.setEditor(editor); 
    editor.getTextField().setFormatterFactory(
     new DefaultFormatterFactory(new DateFormatter(format))); 

    JPanel p = new JPanel(); 
    p.add(spinner); 
    return p; 
    } 
    public static void main(String... args) { 
    EventQueue.invokeLater(() -> { 
     JFrame f = new JFrame(); 
     f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); 
     f.getContentPane().add(new DateEditorTimeZoneTest().makeUI()); 
     f.setSize(320, 240); 
     f.setLocationRelativeTo(null); 
     f.setVisible(true); 
    }); 
    } 
}