Android String variable (HH:mm) to long variable miliseconds

问题

I have a String variable in this format "HH:mm". Lets say the variable value is 05:30.

How would I be able to get those numbers from string and calculate :

(05 * 60 * 60 * 1000) + (30 * 60 * 1000) and put that number (miliseconds) in a new long variable.

Basically I need to convert the String time variable into miliseconds long variable.

回答1:

Let s contain the string of interest. Then e.g. you can say

    String s = "5:30";
    Pattern p = Pattern.compile("(\\d+):(\\d+)");
    Matcher m = p.matcher(s);
    if (m.matches()) {
        int hrs = Integer.parseInt(m.group(1));
        int min = Integer.parseInt(m.group(2));
        long ms = (long) hrs * 60 * 60 * 1000 + min * 60 * 1000;
        System.out.println("hrs="+hrs+" min="+min+" ms="+ms);
    } else {
        throw Exception("Bad time format");
    }

For what it's worth, there are only 86,400,000 milliseconds in a day, so you don't need the long. An int is big enough.

回答2:

You can use the SimpleDateFormat class

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
sdf.setTimeZone(TimeZone.getTimeZone("UTC"));

String inputString =  yourTime + ":00.000"; //Added to string to make HH:mm:ss.SSS format

Date date = sdf.parse("1970-01-01 " + inputString);
System.out.println("in milliseconds: " + date.getTime());        

回答3:

public static void main(String[] args) throws IOException {
    SimpleDateFormat simpleDateFormate = new SimpleDateFormat("HH:mm");
    simpleDateFormate.setTimeZone(TimeZone.getTimeZone("UTC"));
    String inputString = "05:30";
    Date date = null;
    try {
        date = simpleDateFormate.parse( inputString);
    } catch (ParseException e) {
        e.printStackTrace();
    }
    System.out.println("in millSeconds: " + date.getTime());  
    long yourvar=date.getTime();
}

Use SimpleDateFormat

来源：https://stackoverflow.com/questions/15561580/android-string-variable-hhmm-to-long-variable-miliseconds