如何从Java / scala调用jsbeautifier？

Question

我想从Java代码格式化一些json文件，并且想使用著名的http://jsbeautifier.org库。

我遵循了这个问题： 从Java代码调用外部javascript函数 ，但是找不到正确的函数来调用。

我尝试了inv.invokeFunction("js_beautify", json) ，但报告：

java.lang.NoSuchMethodException: no such method: js_beautify

---

我的代码（实际上是Scala，但仅使用Java API）：

val manager = new ScriptEngineManager()
val engine = manager.getEngineByName("JavaScript")
// read script file
engine.eval(FileUtils.readFileToString(new File("beautify.js")))

val inv = engine.asInstanceOf[Invocable]
// call function from script file
inv.invokeFunction("js_beautify", json).asInstanceOf[String]

文件beautify.js的结构为：

(function() {

    // a lot of js code
    // ...

    if (typeof define === "function" && define.amd) {
        // Add support for AMD ( https://github.com/amdjs/amdjs-api/wiki/AMD#defineamd-property- )
        define([], function() {
            return { js_beautify: js_beautify };
        });
    } else if (typeof exports !== "undefined") {
        // Add support for CommonJS. Just put this file somewhere on your require.paths
        // and you will be able to `var js_beautify = require("beautify").js_beautify`.
        exports.js_beautify = js_beautify;
    } else if (typeof window !== "undefined") {
        // If we're running a web page and don't have either of the above, add our one global
        window.js_beautify = js_beautify;
    } else if (typeof global !== "undefined") {
        // If we don't even have window, try global.
        global.js_beautify = js_beautify;
    }
}());

也许我需要从Java提供一些global或window上下文？

---

更新：

我遵循了@tiblu的回答中的“ JSBeautify NetBeans插件”：

class FormatJson {
  def apply(json: String): String = {
    val context = Context.enter()
    context.setLanguageVersion(Context.VERSION_1_6)
    val scope = context.initStandardObjects()
    val reader = new FileReader(new File("beautify.js"))
    context.evaluateReader(scope, reader, "Beautify", 1, null)
    val fct = scope.get("js_beautify", scope).asInstanceOf[org.mozilla.javascript.Function]
    fct.call(context, scope, scope, Array[AnyRef](json)).toString
  }
}

但它报告：

Exception in thread "main" java.lang.ClassCastException: org.mozilla.javascript.UniqueTag cannot be cast to org.mozilla.javascript.Function

并且scope.get("js_beautify", scope)实际上是NOT_FOUND 。

我正在使用"org.mozilla" % "rhino" % "1.7R5"

有什么问题吗？

Answer 1

看看JSBeautify NetBeans插件是如何用Java编写的-https: //github.com/drewhamlett/netbeans-jsbeautify/tree/master/src/com/drewhamlett/jsbeautify