Java 将时间转换为毫秒

我从发射器和系统中获得了时间…我想比较它们，确保差异不超过1亿毫秒

public void test() throws InterruptedException {
    /*
    * Get the visible time from the launcher
    */
    TextView onLauncherDisplay = (TextView) mNextUIMainActivity.findViewById(R.id.timeOfDay);
    System.out.println("Launcher time:  " + onLauncherDisplay.getText().toString());

    /*
    * Get the system time
    */
    Calendar currentSystemTime = Calendar.getInstance();
    currentSystemTime.setTime(new Date());

    Calendar currentSystemTImeInMIlliseconds = Calendar.getInstance();
    currentSystemTImeInMIlliseconds.seu
    /*
    * Convert time into 12-hour format
    */
    SimpleDateFormat date = new SimpleDateFormat("h:mm aa");

    Calendar onLauncherTime = Calendar.getInstance();
    try {
        onLauncherTime.setTime(date.parse(onLauncherDisplay.getText().toString()));
    } catch (ParseException e) {
        e.printStackTrace();
    }

    System.out.println("System time:  " + currentSystemTime.get(Calendar.HOUR) + ":" + currentSystemTime.get(Calendar.MINUTE));

/*
* Compare the Launcher time with the System time
*/
if ((onLauncherTime.get(Calendar.HOUR) == currentSystemTime.get(Calendar.HOUR)) || (currentSystemTime.get(Calendar.HOUR) - onLauncherTime.get(Calendar.HOUR) == 1)) {
    if (onLauncherTime.get(Calendar.MINUTE) == currentSystemTime.get(Calendar.MINUTE) || (currentSystemTime.get(Calendar.MINUTE) - onLauncherTime.get(Calendar.MINUTE) == 1)) {
        System.out.println("Launcher time matches the On-System time!");
    }
} else {
    System.out.println("Launcher time does not matches the On-System time!!");
}

在这里，我比较了时间…小时和分钟，但它并不完美。我想转换成毫秒，差值不应该超过100毫秒

public void test() throws InterruptedException {
    /*
    * Get the visible time from the launcher
    */
    TextView onLauncherDisplay = (TextView) mNextUIMainActivity.findViewById(R.id.timeOfDay);
    System.out.println("Launcher time:  " + onLauncherDisplay.getText().toString());

    /*
    * Get the system time
    */
    Calendar currentSystemTime = Calendar.getInstance();
    currentSystemTime.setTime(new Date());

    Calendar currentSystemTImeInMIlliseconds = Calendar.getInstance();
    currentSystemTImeInMIlliseconds.seu
    /*
    * Convert time into 12-hour format
    */
    SimpleDateFormat date = new SimpleDateFormat("h:mm aa");

    Calendar onLauncherTime = Calendar.getInstance();
    try {
        onLauncherTime.setTime(date.parse(onLauncherDisplay.getText().toString()));
    } catch (ParseException e) {
        e.printStackTrace();
    }

    System.out.println("System time:  " + currentSystemTime.get(Calendar.HOUR) + ":" + currentSystemTime.get(Calendar.MINUTE));

/*
* Compare the Launcher time with the System time
*/
if ((onLauncherTime.get(Calendar.HOUR) == currentSystemTime.get(Calendar.HOUR)) || (currentSystemTime.get(Calendar.HOUR) - onLauncherTime.get(Calendar.HOUR) == 1)) {
    if (onLauncherTime.get(Calendar.MINUTE) == currentSystemTime.get(Calendar.MINUTE) || (currentSystemTime.get(Calendar.MINUTE) - onLauncherTime.get(Calendar.MINUTE) == 1)) {
        System.out.println("Launcher time matches the On-System time!");
    }
} else {
    System.out.println("Launcher time does not matches the On-System time!!");
}

---

Calendar

类有一个

getTimeInMillis

返回给定日历的unix epoc时间值。也就是说，我不完全理解你在做什么…

使用

Calendar.getTimeInMillis（）

：

---

if（currentSystemTime.getTimeInMillis（）-onLauncherTime.getTimeInMillis（）<100）
//差值小于100毫秒

但它并不完美

它怎么不完美？到底出了什么问题？我想将启动时间和系统时间转换为毫秒onLauncherTime的可能副本。getTimeInMillis（）无法正常工作。注意更具体一点吗？对于onLauncherTime，我认为默认时间为1970年1月1日……而对于当前时间，则假定为今天的日期