Groovy：使用字符串作为路径设置动态嵌套方法 [英] Groovy: Set dynamic nested method using string as path

问题描述

我有一个对象内的对象的路径，我想使用Groovy的动态能力进行设置。通常你可以这样做：

I have a path for an object within an object within an object and I want to set it using Groovy's dynamic abilities. Usually you can do so just by doing the following:

class Foo {
  String bar
}


Foo foo = new Foo
foo."bar" = 'foobar'

可以正常工作。但是如果你有嵌套对象呢？如下：

That works OK. But what if you have nested objects? Something like:

class Foo {
  Bar bar
}

class Bar {
  String setMe
}

现在我想使用动态设置，但是

Now I want to use the dynamic setting, but

Foo foo = new Foo()
foo."bar.setMe" = 'This is the string I set into Bar'

返回MissingFieldException。

Returns a MissingFieldException.

任何提示？

更新：感谢Tim指出正确的方向，那里的初始代码在检索属性方面非常有用，但是我需要使用路径字符串设置值。

UPDATE: Thanks to Tim for pointing me in the right direction, the initial code on there works great at retrieving a property, but I need to set the value using the path string.

这是我从页面提出的建议：

Here's what I came up with from the page Tim suggested:

  def getProperty(object, String propertyPath) {
    propertyPath.tokenize('.').inject object, {obj, prop ->
      obj[prop]
    }
  }

  void setProperty(Object object, String propertyPath, Object value) {
    def pathElements = propertyPath.tokenize('.')
    Object parent = getProperty(object, pathElements[0..-2].join('.'))
    parent[pathElements[-1]] = value
  }

推荐答案

以下工作正常。

foo."bar"."setMe" = 'This is the string I set into Bar';

没有getProperty覆盖，您可以使用GString的$ {}语法来实现相同的结果，如下所示代码演示

Without getProperty overriding you can achieve the same result using "${}" syntax for GString as the below code demonstrates

class Baz {
    String something
}

class Bar {

    Baz baz

}

class Foo {
    Bar bar
}

def foo = new Foo()
foo.bar = new Bar()
foo.bar.baz = new Baz()

def target = foo
def path = ["bar", "baz"]
for (value in path) {
    target = target."${value}"
}

target."something" = "someValue"
println foo.bar.baz.something

final println按预期打印someValue

final println prints "someValue" as expected

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