日历问题，不保存日期

Question

所以我写了一些代码，以节省在无线网络上花费的时间。除了时间没有正确保存，我几乎在那里。

该对象接收广播，之后检查它是否连接到wifi AP。它在连接的时刻获取Date对象。断开连接后，获取连接中断的日期。

然而，当它记录的开始和结束日期似乎总是得到当前的日期，也为起始对象：

private Date startDate; 
private Date stopDate; 
@Override 
public void onReceive(Context context, Intent intent) { 
    if (isOnline(context)) { 
     WifiManager wifiManager = (WifiManager) context 
       .getSystemService(Context.WIFI_SERVICE); 
     android.net.wifi.WifiInfo wifiInfo = wifiManager 
       .getConnectionInfo(); 
     Log.d("WIFI:", "IN FIRST IF, SO CONNECTED"); 
     if (wifiInfo.getSupplicantState() == (SupplicantState.COMPLETED)) { 
      Calendar c = Calendar.getInstance(); 
      this.startDate = c.getTime(); 
      this.initialConnection = true; 
     } 
    } else if (this.initialConnection) { 
     Calendar d = Calendar.getInstance(); 
     this.stopDate = d.getTime(); 
     //problem persists here 
     String s = "TIME:" + d.getTime().toString() + " started at:" 
       + startDate.toString() + "stopped at" 
       + this.stopDate.toString(); 
     Log.d("WIFI:", s); 
     this.initialConnection = false; 
    } 
} 

输出

D/WIFI: ( 684): TIME:Mon Mar 12 13:18:16 GMT+02:00 2012 started at:Mon Mar 12 13:18:16 GMT+02:00 2012stopped atMon Mar 12 13:18:16 GMT+02:00 2012 

是我的开始时间获取当前时间再次提到它时？我怎样才能让它保存startTime？

Answer 1

我无法找到使用日历的任何错误。以下SSCCE具有正确的行为。 onReceive（）中的逻辑必定存在问题。也许上半场被再次调用导致startDate被更新到当前时间。

public class CalendarTest { 
    private Date stopDate; 
    private Date startDate; 

    public void online() { 
     Calendar c = Calendar.getInstance(); 
     this.startDate = c.getTime(); 
    } 

    public void offline() { 
     Calendar d = Calendar.getInstance(); 
     this.stopDate = d.getTime(); 
     String s = "TIME:" + d.getTime().toString() + "\nstarted at:" 
       + startDate.toString() + "\nstopped at" 
       + this.stopDate.toString(); 
     System.out.println(s); 
    } 

    public static void main(String[] args) { 
     CalendarTest test = new CalendarTest(); 
     test.online(); 
     try { 
      Thread.sleep(3000); 
     } catch (InterruptedException e) { 
      e.printStackTrace(); 
     } 
     test.offline(); 
    } 
} 

输出

TIME:Mon Mar 12 12:29:04 GMT 2012 
started at:Mon Mar 12 12:29:01 GMT 2012 
stopped atMon Mar 12 12:29:04 GMT 2012