从java代码调用javascript(jQuery/Envjs)

Question

我试图从Java执行Javascript代码。Javascript代码使用jquery，所以我在代码之前添加jquery.js。但是它会抛出以下异常

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

当我从Java代码中运行它时，我明白它没有访问窗口对象的权限，所以上面的异常。我发现EnvJs提供了所需环境的实现，所以我尝试先加载它，先将其内容放在首位，同时为eval生成脚本内容。但是遇到以下异常，

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

下面是代码片段

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);

我不使用任何浏览器功能，所以不需要对象的窗口。所以理想情况下，我不想加载Envjs。请告诉我如何加载jQuery代码。

还有一个问题-如何将Json对象从Java代码传递到Javascript函数作为参数?

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

Answer 1

使用Envjs指南(http://www.envjs.com/doc/guides#running-embed)的说明使用Rhino可能更容易做到这一点。

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);

Answer 2

不知道Envjs，但为什么要在java中模拟浏览器环境?

回答第二个问题:

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); 

你可以将任何对象放入绑定中，映射、列表或pojo。