Java 7 executable Nashorn, instead of Rhino

Source: Internet
Author: User

Surprise the existing people on the OpenJDK on the Nashorn dump down, so that Java 7 can be used. The source code is in https://bitbucket.org/ramonza/nashorn-backport/.

Originally Nashorn is Java 8 only. Now someone is backwards compatible. Good!

Compiling source code

Only the source code does not have a jar. To compile it yourself. It doesn't matter very easy:ant-f make/build.xml. The detailed steps first drag the source code into the Eclipse project. Then open the Ant view:


Click the + icon to add Make/build.xml


Then "Run" to compile the jar package, and then save it in the Dist folder.

Suppose you can't compile successfully, give everyone a direct: http://download.csdn.net/detail/zhangxin09/9398572

Test

Test is available:

Import javax.script.*; public class Nashorntest {public static void main (String args[]) {Scriptenginemanager manager = new Scriptenginemanager (); For (Scriptenginefactory f:manager.getenginefactories ()) {printbasicinfo (f); System.out.println ();} ScriptEngine Nashorn = Manager.getenginebyname ("Nashorn"), if (Nashorn! = null) {System.out.println ("Nashorn is present."); }else {System.out.println ("Nashorn is not present.");} public static void Printbasicinfo (Scriptenginefactory factory) {System.out.println ("engine name=" + Factory.getenginename ()); System.out.println ("engine version=" + factory.getengineversion ()); System.out.println ("Language name=" + factory.getlanguagename ()); System.out.println ("extensions=" + factory.getextensions ()); System.out.println ("Language version=" + factory.getlanguageversion ()); System.out.println ("names=" + factory.getnames ()); System.out.println ("MIME types=" + factory.getmimetypes ());}}

Another way to check if it is available: try{final class<?> cls = Class.forName ("Jdk.nashorn.api.scripting.ScriptObjectMirror");

Compare Rhino

Create an already encapsulated JS VM

Nashorn n = new Nashorn (); Object s = N.eval ("g={a:1};"); Map SS = (map) s;ss.get ("a"); System.out.println (Ss.get ("a"). GetClass (). GetName ()); System.out.println (S.getclass (). GetName ());

The API I encapsulated feels more comfortable, such as:

Map s = N.eval ("g={a:1};", Map.class); JS Object converted to Java map

        Nashorn n = new Nashorn (), Object obj = N.eval ("G=[1, 2, 3];"); System.out.println (Obj.getclass (). GetName ()); Scriptobjectmirror so = (scriptobjectmirror) obj; System.out.println (So.get (0). GetClass (). GetName ());
Test observations revealed that:

The {} hash type of JS will be actively converted to jdk.nashorn.api.scripting.ScriptObjectMirror. Rather than Rhino's nativeobject. But both can switch to MAP.

JS's [] array type will take its own initiative to Jdk.nashorn.api.scripting.ScriptObjectMirror, not Rhino's nativearray, but be able to use IsArray (): Boolean to infer whether an array

JS number type will take the initiative to convert to Java.lang.Integer. Instead of a Double in Rhino, this is more convenient when dealing with numeric types.

Just this is the earlier version number. Lack of a formal version of the function. Like what:

if (So.isarray ()) {  int[] Iarr = (int[]) Scriptutils.convert (So, int[].class);//Convert to Java array save. Because there is no convert ()}

What can I do but what will we do? Think of a way to do (in fact, Google a bit).

public static void Main (string[] args) throws Scriptexception, IOException {nashorn n = new Nashorn (); N.load ("c:/project/s Pring-test/src/com/ajaxjs/framework/config.js "), Object obj = N.eval (" G=[1, 2, 3]; "); System.out.println (Obj.getclass (). GetName ()); Scriptobjectmirror so = (scriptobjectmirror) obj; System.out.println (So.get (0). GetClass (). GetName ()); if (So.isarray ()) {System.out.println (so);//int[] Iarr = (int[]) Scriptutils.convert (So, int[].class);}} /** * js arr2 java arr * @param scriptobjectmirror * @return */public static object[] ToArray (scriptobjectmirror scriptobj Ectmirror) {if (!scriptobjectmirror.isarray ()) {throw new IllegalArgumentException ("Scriptobjectmirror is no Array");} if (Scriptobjectmirror.isempty ()) {return new object[0];} object[] Array = new Object[scriptobjectmirror.size ()];int i = 0;for (map.entry<string, object> entry:scriptobject Mirror.entryset ()) {Object result = Entry.getvalue (); if (Result instanceof scriptobjectmirror && Scriptobjectmirror.isArray ()) {Array[i] = ToArray ((scriptobjectmirror) result);} else {array[i] = result;} i++;} return array;}

In fact, suppose you're not obsessive-compulsive. Array get (0)/get (1)/... is available without conversion.

Single-gauge code (very important!)

) Http://code.taobao.org/p/bigfoot_v2/src/java_v3/test/javascript/TestJS.java

Nashorn Document: http://cr.openjdk.java.net/~sundar/jdk.nashorn.api/8u20/javadoc/jdk/nashorn/api/scripting/AbstractJSObject.html

Java 7 executable Nashorn, instead of Rhino

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