1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
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   8  *   - Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  *
  11  *   - Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *
  15  *   - Neither the name of Oracle nor the names of its
  16  *     contributors may be used to endorse or promote products derived
  17  *     from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 
  32 // Converting between #javascript Date and #java8 LocalDateTime with #nashorn
  33 
  34 // JavaScript Date with current time
  35 var d = new Date();
  36 print(d);
  37  
  38 // Java 8 java.time classes used
  39 var Instant = java.time.Instant;
  40 var LocalDateTime = java.time.LocalDateTime;
  41 var ZoneId = java.time.ZoneId;
  42  
  43 // Date.prototype.getTime
  44 
  45 // getTime() method returns the numeric value corresponding to the time
  46 // for the specified date according to universal time. The value returned
  47 // by the getTime() method is the number of milliseconds since 1 January 1970 00:00:00 UTC.
  48 // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getTime
  49  
  50 // Java Instant.ofEpochMilli to convert time in milliseconds to Instant object
  51 // https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html#ofEpochMilli-long-
  52  
  53 var instant = Instant.ofEpochMilli(d.getTime());
  54  
  55 // Instant to LocalDateTime using LocalDateTime.ofInstant
  56 // https://docs.oracle.com/javase/8/docs/api/java/time/LocalDateTime.html#ofInstant-java.time.Instant-java.time.ZoneId-
  57  
  58 var ldt = LocalDateTime.ofInstant(instant, ZoneId.systemDefault());
  59 print(ldt);
  60  
  61 // converting a LocalDateTime to JavaScript Date
  62 // convert LocalDateTime to Instant first
  63 // https://docs.oracle.com/javase/8/docs/api/java/time/LocalDateTime.html#atZone-java.time.ZoneId-
  64  
  65 var instant = ldt.atZone(ZoneId.systemDefault()).toInstant();
  66  
  67 // instant to to epoch milliseconds
  68 // https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html#toEpochMilli--
  69 // and then to JavaScript Date from time in milliseconds
  70 // https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Date
  71 
  72 var d1 = new Date(instant.toEpochMilli());
  73 print(d1);