根据键名获取值时，地图返回null

Question

I have a very strange problem regarding getting values from LinkedHashMap in Grovvy when running in Jenkins pipeline.

I have a map like this: map = ['key1': 'param1']

Now I want to get a value of key1, so I call map.get('key1') or map['key1'] . Surprisingly both of these return null .

When I try to call map.keySet() , it returns key1 . And most interestingly, when I call map.get(map.keySet()[0]) it return param1 as expected.

So how is it possible that the direct map.get('key1') doesn't work?

UPDATE:

After some investigation, I have found out that the key1 is not a String but org.codehaus.groovy.runtime.GStringImpl . Does anybody have any idea why it was casted to this class and not String?

This is how the initial map is created:

result = ["${key}": value]

Answer 1

Following code does work.

map = ['key1': 'param1']
assert 'param1' == map['key1']

After the update in Question

The key was actually not a String. toString() will give to you string as String , that can be used as key

Answer 2

GStrings (groovy.lang.GString) which are also called interpolated strings in other programming languages. "${key}" is a GString, but "${key}".toString() is a String. More detail at here

Following approach can resolve your issue

def key = 'key1'
def a = "${key}"  // or a = "${key}".toString()
def result = [:]
result[a] = 'param1'
println result.key1 // or result['key1']