Groovy - 将属性从一个对象绑定到另一个对象

时间:2009-09-03 00:04:17

标签: groovy

是否有办法将属性从一个类的实例绑定到另一个类的实例的属性(两者之间的公共字段)。请参阅以下示例:

class One {
  String foo
  String bar
}

class Two {
  String foo
  String bar
  String baz
}

def one = new One(foo:'one-foo', bar:'one-bar')
def two = new Two()

two.properties = one.properties

assert "one-foo" == two.foo
assert "one-bar" == two.bar
assert !two.baz

结果是错误:无法设置readonly属性:类的属性:两个

2 个答案:

答案 0 :(得分:9)

我会按照我的建议here选择 InvokerHelper.set属性

use(InvokerHelper) {
    two.setProperties(one.properties)
}

答案 1 :(得分:6)

问题在于,对于每个对象,.properties都包含两个内置的 Groovy定义的属性,这些属性是metaClassclass。您要做的只是设置用户定义的属性。您可以使用如下所示的代码轻松完成此操作:

class One {
  String foo
  String bar
}

class Two {
  String foo
  String bar
  String baz
}

def one = new One(foo:'one-foo', bar:'one-bar')

// You'll probably want to define a helper method that does the following 3 lines for any Groovy object
def propsMap = one.properties
propsMap.remove('metaClass')
propsMap.remove('class')

def two = new Two(propsMap)

assert "one-foo" == two.foo
assert "one-bar" == two.bar
assert !two.baz