groovy - 通过动态键访问 groovy 映射

Question

我想要一个如下所示的带有动态键的常规映射，并希望通过动态键获取值。但我无法访问它，它为同一键返回 null。

class AmazonPackage {
    public static String WEIGHT = "WEIGHT"
}

class PackageTests {

   @Test
   void "map should return value by dynamic key" () {
       def map = [ ("${AmazonPackage.WEIGHT}") : 100, "id": "package001"]

       assert map['id'] == "package001"

       //assert map[("${AmazonPackage.WEIGHT}")] == 100
       //assert map."${AmazonPackage.WEIGHT}" == 100

       assert 2 == map.keySet().size()
       assert map."WEIGHT" == 100 //fails
    }

    @Test
    void "map should return value by simple key" () {
        def map = ["w" : 100]
        assert map."w" == 100
    }

}

我得到的失败是，

Assertion failed: 

assert map."WEIGHT" == 100
       |   |        |
       |   null     false
       [WEIGHT:100, id:package001]

Answer 1

不幸的是，您存储的 map 键是 GString，而不是 String。这意味着 map 不认为这些键相等。

如果您想使用字符串值访问您的 map ，您应该将键存储为字符串:

def map = [ ("${AmazonPackage.WEIGHT}".toString()) : 100, "id": "package001"]
assert map."WEIGHT" == 100