I would like to run javascript using the embedded javascript engine of Java 7. The code which I am trying to run is ECMAScript 5 compliant, which should not be a problem since the embedded Rhino's version is 1.7 release 3 which supports it. Yet, running the following snippet doesn't work:
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
engine.eval("var char = 'a';");
It fails with the error missing variable name
which indicates that char
is a reserved keyword. However, the char
is no longer reserved in ECMAScript 5, so I am completely confused. The question is which javascript version is supposed to work with the embedded Rhino in java 7?
I am using java 1.7.0_80
, the language version reported by the engine is 1.8
and the engine version is 1.7 release 3 PRERELEASE
.
As @RealSkeptic pointed out, the embedded script engine of OpenJDK 7 ( Rhino 1.7 r4
) has no problem running the above javascript snippet. It seems that Rhino 1.7 r3
can not run it, so running it using Oracle Java 7 needs the external Rhino of 1.7 r4
(or above) which can be downloaded from here . Just for completeness, the java equivalent of the code in the question based on Rhino's own API looks like this:
import org.mozilla.javascript.Context;
import org.mozilla.javascript.ScriptableObject;
public class Rhino {
public static void main(String[] args) throws Exception {
Context context = Context.enter();
try {
ScriptableObject scope = context.initStandardObjects();
context.evaluateString(scope, "var char = 'a'", "test", 1, null);
} finally {
Context.exit();
}
}
}
Note that the import declarations are important since the same classes are available bundled in the JDK within a different package:
import sun.org.mozilla.javascript.internal.Context;
import sun.org.mozilla.javascript.internal.ScriptableObject;
Importing them yields in using the embedded engine with Rhino's API which will not work.
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