blocks|key|1265036|text|Calendar.setTime()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1265037|查看API方法的签名和描述通常很有用，而不仅仅是它们的名称:)+-即使在Java标准API中，名称有时也会产生误导。|1265038|entityMap|0|LINK|mutability|MUTABLE|url|http://java.sun.com/javase/6/docs/api/java/util/Calendar.html#setTime(java.util.Date)^0|0|I|0|I|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@$9|S|A|T|1|U]]|E|$]]|$1|F|3|G|5|6|7|V|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]]]

<a href="http://java.sun.com/javase/6/docs/api/java/util/Calendar.html#setTime(java.util.Date)" rel="noreferrer"><code>Calendar.setTime()</code></a>

It's often useful to look at the signature and description of API methods, not just their name :) - Even in the Java standard API, names can sometimes be misleading.

blocks|key|1050407|text|Calendar+tCalendar+=+Calendar.getInstance();
tCalendar.setTime(date);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1050408|date是一个java.util.Date对象。您也可以使用Calendar.getInstance()来获得Calendar实例(效率更高)。|unstyled|1050409|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>Calendar tCalendar = Calendar.getInstance();
tCalendar.setTime(date);
</code></pre>

date is a java.util.Date object. You may use Calendar.getInstance() as well to obtain the Calendar instance(much more efficient).

blocks|key|1265162|text|您可以做的是创建一个GregorianCalendar实例，然后将Date设置为开始时间：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1265163|Date+date;
Calendar+myCal+=+new+GregorianCalendar();
myCal.setTime(date);|code-block|syntax|javascript|1265164|然而，另一种方法是根本不使用Date。您可以使用如下方法：|1265165|private+Calendar+startTime;
private+long+duration;
private+long+startNanos;+++//Nano-second+precision,+could+be+less+precise
...
this.startTime+=+Calendar.getInstance();
this.duration+=+0;
this.startNanos+=+System.nanoTime();

public+void+setEndTime()+{
++++++++this.duration+=+System.nanoTime()+-+this.startNanos;
}

public+Calendar+getStartTime()+{
++++++++return+this.startTime;
}

public+long+getDuration()+{
++++++++return+this.duration;
}|1265166|通过这种方式，您可以访问开始时间并获得从开始到停止的持续时间。当然，精确度取决于您。|1265167|entityMap^0|A|H|X|4|0|0|E|4|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|12|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|R|$]]

What you could do is creating an instance of a <code>GregorianCalendar</code> and then set the <code>Date</code> as a start time:

<pre><code>Date date;
Calendar myCal = new GregorianCalendar();
myCal.setTime(date);
</code></pre>

However, another approach is to not use <code>Date</code> at all. You could use an approach like this:

<pre><code>private Calendar startTime;
private long duration;
private long startNanos; //Nano-second precision, could be less precise
...
this.startTime = Calendar.getInstance();
this.duration = 0;
this.startNanos = System.nanoTime();

public void setEndTime() {
 this.duration = System.nanoTime() - this.startNanos;
}

public Calendar getStartTime() {
 return this.startTime;
}

public long getDuration() {
 return this.duration;
}
</code></pre>

In this way you can access both the start time and get the duration from start to stop. The precision is up to you of course.

blocks|key|1265174|text|就像这样|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1265175|movie.setStopDate(movie.getStartDate()+%2B+movie.getDurationInMinutes()*+60000);|code-block|syntax|javascript|1265176|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

something like

<pre><code>movie.setStopDate(movie.getStartDate() + movie.getDurationInMinutes()* 60000);
</code></pre>

blocks|key|1265186|text|下面是一个完整的例子，告诉你如何将你的date转换成不同的类型：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1265187|Date+date+=+Calendar.getInstance().getTime();

++++//+Display+a+date+in+day,+month,+year+format
++++DateFormat+formatter+=+new+SimpleDateFormat("dd/MM/yyyy");
++++String+today+=+formatter.format(date);
++++System.out.println("Today+:+"+%2B+today);

++++//+Display+date+with+day+name+in+a+short+format
++++formatter+=+new+SimpleDateFormat("EEE,+dd/MM/yyyy");
++++today+=+formatter.format(date);
++++System.out.println("Today+:+"+%2B+today);

++++//+Display+date+with+a+short+day+and+month+name
++++formatter+=+new+SimpleDateFormat("EEE,+dd+MMM+yyyy");
++++today+=+formatter.format(date);
++++System.out.println("Today+:+"+%2B+today);

++++//+Formatting+date+with+full+day+and+month+name+and+show+time+up+to
++++//+milliseconds+with+AM/PM
++++formatter+=+new+SimpleDateFormat("EEEE,+dd+MMMM+yyyy,+hh:mm:ss.SSS+a");
++++today+=+formatter.format(date);
++++System.out.println("Today+:+"+%2B+today);|code-block|syntax|javascript|1265188|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here is a full example on how to transform your date in different types:

<pre><code>Date date = Calendar.getInstance().getTime();

 // Display a date in day, month, year format
 DateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
 String today = formatter.format(date);
 System.out.println("Today : " + today);

 // Display date with day name in a short format
 formatter = new SimpleDateFormat("EEE, dd/MM/yyyy");
 today = formatter.format(date);
 System.out.println("Today : " + today);

 // Display date with a short day and month name
 formatter = new SimpleDateFormat("EEE, dd MMM yyyy");
 today = formatter.format(date);
 System.out.println("Today : " + today);

 // Formatting date with full day and month name and show time up to
 // milliseconds with AM/PM
 formatter = new SimpleDateFormat("EEEE, dd MMMM yyyy, hh:mm:ss.SSS a");
 today = formatter.format(date);
 System.out.println("Today : " + today);
</code></pre>

blocks|key|1050557|text|用于在Kotlin中将日期转换为日历的扩展。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1050558|fun+Date?.toCalendar():+Calendar?+{
++++return+this?.let+{+date+->
++++++++val+calendar+=+Calendar.getInstance()
++++++++calendar.time+=+date
++++++++calendar
++++}
}|code-block|syntax|javascript|1050559|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Extension for converting date to calendar in Kotlin.
<pre><code>fun Date?.toCalendar(): Calendar? {
 return this?.let { date -&gt;
 val calendar = Calendar.getInstance()
 calendar.time = date
 calendar
 }
}
</code></pre>

I have a class Movie
in it i have a start Date, a duration and a stop Date.
Start and stop Date are Date Objects (private Date startDate ...)
(It's an assignment so i cant change that)
now I want to automatically calculate the stopDate by adding the duration (in min) to the startDate.

By my knowledge working with the time manipulating functions of Date is deprecated hence bad practice but on the other side i see no way to convert the Date object to a calendar object in order to manipulate the time and reconvert it to a Date object.
Is there a way? And if there is what would be best practice

Date object to Calendar [Java]

Kotlin

Java

我有一个班级电影，我有一个开始日期，一个持续时间和一个停止日期。开始和停止日期是Date对象(私有Date startDate ...)(这是一个赋值，所以我不能改变这一点)现在我想通过将持续时间(以分钟为单位)添加到startDate来自动计算stopDate。据我所知，不推荐使用Date的时间操作函数，因此这是一种...

问日历的日期对象[Java]
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