Using Java with Other Languages - Java - page 962

Because R treats all numbers as floating point, like many interpreters, the value printed is
84.0 .

You can also find out the installed scripting engines and pick one that is on your classpath.
The ScriptEnginesDemo program in Example 24-7 lists the installed engines, and runs a
simple script in the default language, ECMAScript (aka JavaScript).

Example 24-7. ScriptEnginesDemo.java
public public class class ScriptEnginesDemo ScriptEnginesDemo {

public public static throws ScriptException {

ScriptEngineManager scriptEngineManager = new

static void void main ( String [] args ) throws

new ScriptEngineManager ();

// Print list of supported languages
scriptEngineManager . getEngineFactories (). forEach ( factory ->
System . out . println ( factory . getLanguageName ()));

// Run a script in the JavaScript language
String lang = "ECMAScript" ;
ScriptEngine engine =
scriptEngineManager . getEngineByName ( lang );
iif ( engine == null null ) {

System . err . println ( "Could not find engine" );
return

return ;

}
engine . eval ( "print(\"Hello from " + lang + "\");" );

}

}

See Also

To see the full list of languages, and download the “script engines”—the interfaces from Java
to each of the languages—visit the Oracle page or the java.net page .

At present, the website is borked; to view the list of engines at Java.net you have to save the
file and open it manually; the web server dishes it with the wrong content type.

The list maintained as part of the scripting project per se can be found at the source code re-
pository, by viewing Java.net . A dozen or so other engines are maintained by others outside
this project; for example, there is a Perl5 script engine from Google .