在Java中将float转换为时间？

Question

Is it possible to convert a float to a time in Java?

I'm new to web services and I'm trying to invoke a simple sunrise/sunset time webservice, the WSDL for this is here

I've passed the service a latitude (34.0888), longitude (-118.40612), day, month and year and I have got values back:

sunrise: 13.6935135 sunset: 26.607845

But the values are floats, does anyone know why this would be? Or if it is possible to work out a time from them? I thought it might be unix time but I've not had much luck with that.

Any help is appreciated, thanks

Answer 1

That's probably a number of hours relative to UTC. I would try something like this:

Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.add(Calendar.HOUR_OF_DAY, (int) sunrise);
calendar.set(Calendar.MINUTE, (sunrise * 60) % 60);
calendar.set(Calendar.SECOND, (sunrise * 3600) % 3600);

Then display the date in the timezone you want with a DateFormat :

DateFormat fmt = new SimpleDateFormat();
fmt.setTimeZone(TimeZone.getTimeZone("Europe/Paris")); 
System.out.println(fmt.format(calendar.getTime()));

Answer 2

看起来不是一件很容易计算的东西...这里有一个完整的包来处理： https ： //github.com/mikereedell/sunrisesunsetlib-java

Answer 3

Float sunriseFloat = new Float(sunrise);  
Float sunsetFloat = new Float(sunset);

    Date startDate = new Date(sunriseFloat.longValue());  
    Date endDate = new Date(sunsetFloat.longValue());

Answer 4

It seems this is not a java problem, and you found a webservice with a underspecified interface. I googled for a solution and I found several libraries able to calculate sunrise and sunset. For example, this was one of the first results: http://www.jstott.me.uk/jsuntimes/