Java对象可以成为Nashorn中JavaScript对象的原型吗？

Is it possible to make an Java object the prototype of a JavaScript object? Like the following:

是否有可能使Java对象成为JavaScript对象的原型？如下：

var Person = Java.type("Person");
var hans = new Person();
hans.name = "Hans";

var employeeFactory = function() {
    var F = function(){};
    F.prototype = hans;
    return new F();
};

var fritz = employeeFactory();
print(fritz.name);

Here Person is a Java Bean. The variable hans is set as the instance of this Java class. The line hans.name = "Hans" sets the name field in the Java object as expected. But when the object fritz is created in the factory function, it doesn't get linked to the expected prototype. Is there any reason why the Java instance isn't accepted as prototype?

这里Person是一个Java Bean。变量hans被设置为此Java类的实例。行hans.name =“Hans”按预期在Java对象中设置名称字段。但是当在工厂函数中创建对象fritz时，它不会链接到预期的原型。是否有任何理由不接受Java实例作为原型？

1 个解决方案

#1

It might work in Rhino, because in Rhino all beans are wrapped into JS native objects before being exposed to the JS program. Nashorn OTOH doesn't create wrappers. You can, however, use Nashorn's non-standard Object.bindProperties that adds properties from one object to another, bound to the original object's instance as its this. That's essentially as close as you can get (well, it's pretty darn close) to a wrapper. The exact specification is:

它可能适用于Rhino，因为在Rhino中，所有bean在暴露给JS程序之前都被包装到JS本机对象中。 Nashorn OTOH不会创建包装器。但是，您可以使用Nashorn的非标准Object.bindProperties，它将属性从一个对象添加到另一个对象，并将其绑定到原始对象的实例。这基本上就像你可以得到的那样接近（好吧，它非常接近）一个包装器。确切的规格是：

Object.bindProperties(dst, src)

creates bound properties from all properties in src object, puts them into the dst object, and returns the dst object. Since the properties are bound to src, dst.foo will delegate to src.foo for its value. bindProperties has been coded specifically so that it can handle ordinary Java objects as src.

从src对象中的所有属性创建绑定属性，将它们放入dst对象，并返回dst对象。由于属性绑定到src，dst.foo将委托给src.foo获取其值。 bindProperties已经过专门编码，因此它可以像src一样处理普通的Java对象。

With that in mind, I believe that if you change the line

考虑到这一点，我相信如果你改变了这条线

F.prototype = hans;

至

F.prototype = Object.bindProperties({}, hans);

you'll get what you wanted. That would work with Object.create too, e.g. Object.create(Object.bindProperties({}, somePojo)).

你会得到你想要的。这也适用于Object.create，例如Object.create（Object.bindProperties（{}，somePojo））。

#1

Object.bindProperties(dst, src)