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I am trying to execute Javascript code from Java. Javascript code uses jquery so I prepend the jquery.js before my code. But it throws following exception,

Exception in thread "main" javax.script.ScriptException: sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "window" is not defined. (<Unknown source>#1) in <Unknown source> at line number 1

As I run this from the Java code, I understand that it does not have access to the window object so above exception. I found that EnvJs provides the implementation for the required environment so I tried to load that first by putting its content first while generating the script content to eval. But run into following exception,

Exception in thread "main" javax.script.ScriptException: sun.org.mozilla.javascript.internal.EcmaError: TypeError: Cannot call property getCurrentContext in object [JavaPackage org.mozilla.javascript.Context]. It is not a function, it is "object". (<Unknown source>#1247) in <Unknown source> at line number 1247


Following is the code snippet,

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");

String script = "Envjs code" + "jQuery code" + "my java script"; //code of envjs + jquery from the link provided at the end
engine.eval(script);

Invocable inv = (Invocable) engine;
inv.invokeFunction("myFunc", obj1, obj2);


I do not use any browser features so do not require object's like window. So ideally I do not want to load Envjs. Please let me know how to load jQuery code.


One more question - How to pass Json Object from Java code to Javascript function as parameter?


http://www.envjs.com/dist/env.rhino.1.2.js
http://code.jquery.com/jquery-1.9.0.min.js

Sun
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2 Answers2

1

It may be easier to do this with Rhino using the instructions from the Envjs Guide ( http://www.envjs.com/doc/guides#running-embed ).

import org.mozilla.javascript.Context;
import org.mozilla.javascript.ContextFactory;
import org.mozilla.javascript.tools.shell.Global;
import org.mozilla.javascript.tools.shell.Main;
...
Context cx = ContextFactory.getGlobal().enterContext();
cx.setOptimizationLevel(-1);
cx.setLanguageVersion(Context.VERSION_1_5);
Global global = Main.getGlobal();
global.init(cx);
Main.processSource(cx, "path/to/your/EnvJSfile");
Main.processSource(cx, "path/to/your/JQueryJSfile");
cx.evaluateString(global, "your JavaScript", "JavaScript", 1, null);
AndyJW
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0

don't known about Envjs, but why simulate a browser environment in java?

for the second question:

ScriptEngine engine = new ScriptEngineManager().getEngineByName("javascript");
Compilable compilable = (Compilable) engine;
Bindings bindings = engine.createBindings(); 
String script = "function add(op1,op2){return op1+op2} add(a, b)"; 
CompiledScript jsFunction = compilable.compile(script);
bindings.put("a", 1);bindings.put("b", 2); //put java object into js runtime environment
Object result = jsFunction.eval(bindings);
System.out.println(result);

you can put whatever object into the bindings, a map, a list, or a pojo.

ltebean
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