Java APIs for Nashorn - Scripting in Java: Integrating with Groovy and JavaScript - page 333

// Get a ZonedDateTime for the system default zone id
ZonedDateTime zdt =
ZonedDateTime.ofInstant(instant, ZoneId.
systemDefault());
System.out.println("Java ZonedDateTime: " + zdt);
}
catch (Exception e) {
e.printStackTrace();
}
}
}
JavaScript Date: Fri Oct 31 2014 18:17:02 GMT-0500 (CDT)
Java ZonedDateTime: 2014-10-31T18:17:02.489-05:00[America/Chicago]
Summary
The Java APIs for Nashorn provide Java classes and interfaces that let you deal with
the Nashorn scripting engine and Nashorn objects directly in Java code. All classes for
Java APIs for Nashorn are in the jdk.nashorn.api.scripting package. Notice that the
Nashorn scripting engine internally uses a lot of other classes in other packages. However,
you are not supposed to use them in your application directly, except for classes from the
jdk.nashorn.api.scripting package.
A Nashorn script can use different types of values and objects such as Number,
String, Boolean types of primitive values, and Object, String, Date, and custom objects.
You can also create Java objects in scripts. The script values of type Number and
Boolean are represented in Java as java.lang.Number and java.lang.Boolean . The
Null type in a script is represented as null in Java. The String primitive type in a script is
represented as java.lang.String in Java. A script object is represented as an object of
the ScriptObjectMirror class in Java.
The NashornScriptEngineFactory and ScriptEngine classes in the jdk.nashorn.
api.scripting package represent the Nashorn script engine factory and script engine,
respectively. You will need to work with these classes directly if you want to pass
options to the Nashorn engine. You can also pass options to the Nashorn engine using
-Dnashorn.args="<options>" on the command-line. If you pass the --globals-per-
engine , to a Nashorn engine, all script contexts will share the globals. By default, script
contexts do not share globals.
The ScriptObjectMirror class contains several methods to add, update, and delete
properties from the script object. The class implements the JSObject and Bindings
interfaces. The JSObject interface lets you treat a script object as a simple Java class,
whereas the Bindings interface lets you treat a script object as a map. You can use
getMember() , getSlot() , and get() methods to get the value of the property of a script
object. You can use setMember() , setSlot() , and put() methods to add or update the
value of a property. You can use the callMember() method to call a method of the script
object. The call() method lets you call a script function, allowing you to pass the this
value for the function invocation. The ScriptObjectMirror class contains several other
methods that let you work with script objects in Java programs.