javascript - 如何从 Java 中获取 JS 对象的属性？

Question

我知道我可以使用Invocable类来调用类上的方法：

import javax.script.{ScriptEngine, ScriptEngineManager, Invocable}

val engine = new ScriptEngineManager().getEngineByExtension("js")

val invoker = engine.asInstanceOf[Invocable]

val person = engine.eval(s"""
  new function () {
    this.name = "Rick";
    this.age = 28;
    this.speak = function () {
      return this.name + "-" + this.age;
    }
  };
""")

invoker.invokeMethod(person, "speak") //returns "Rick-28"

但是，我如何获得name人的属性？我试过 invoker.invokeMethod(person, "name")了，我得到了一个NoSuchMethodError.

Answer 1

您可以将 person 转换为 aJSObject然后调用person.getMember("name")。完整的 Java 示例：

ScriptEngine engine = new ScriptEngineManager()
                           .getEngineByExtension("js");

JSObject rick = (JSObject) engine.eval("new function () {\n" +
        "            this.name = \"Rick\";\n" +
        "            this.age = 28;\n" +
        "            this.speak = function () {\n" +
        "                return this.name + \"-\" + this.age;\n" +
        "            }\n" +
        "        };");

System.out.println(rick.getMember("name"));

或者，如果对象存储在引擎全局范围内，如以下 javascript 源代码：

rick = function() {
  this.name= "Rick";
};

然后你可以打电话

engine.eval("rick.name");