How do I get the annotation value 'used' - groovy

Question

I want to retrieve the annotation value used from MyAnnot. I am getting 3 annotations in the list even though there are only 2. Also, I have tried obtaining the used field of MyAnnot but with no success. I would like to return a map where MyAnnot's used is the key and type as the map's value.
// Then, define your class with it's annotated Fields
class MyClass {
#MyAnnot(used = "Hey", type = "There")
String fielda
#MyAnnot(used = "denn", type = "Ton")
String fieldc
}
def findAllPropertiesForClassWithAnotation(obj, annotClass) {
def op = []
def annos = []
def i = 0
obj.properties.findAll { prop ->
obj.getClass().declaredFields.find {
it.name == prop.key && annotClass in it.declaredAnnotations*.annotationType()
annos=it.declaredAnnotations
i++
if(annos)
op << annos[0] as Set
// println"Props ${annos[0]}"
}
}
op.each{ println "${it} and i is ${i}"}
}
// Then, define an instance of our class
MyClass a = new MyClass(fielda: 'tim', fieldc: 'dennisStar')
// And print the results of calling our method
println findAllPropertiesForClassWithAnotation(a, MyAnnot)

Answer 1

First of all you need to mark you annotation with: #Retention(RetentionPolicy.RUNTIME) to make it available for processing at runtime, so it will be:
#Retention(RetentionPolicy.RUNTIME)
#interface MyAnnot {
String used()
String type()
}
Then, used and type are not fields, nor properties but methods, so they must be invoked and get.
The script will be:
import java.lang.annotation.RetentionPolicy
import java.lang.annotation.Retention
#Retention(RetentionPolicy.RUNTIME)
#interface MyAnnot {
String used()
String type()
}
class MyClass {
#MyAnnot(used="Hey" ,type="There")
String fielda
#MyAnnot(used="denn", type="Ton")
String fieldc
}
def findAllPropertiesForClassWithAnotation( obj, annotClass ) {
def c = obj.getClass()
c.declaredFields.findAll { field ->
field.isAnnotationPresent(annotClass)
}.collect { found ->
def a = found.getAnnotation(annotClass)
[(a.used()): a.type()]
}.sum()
}
MyClass a = new MyClass(fielda: 'tim', fieldc: 'dennisStar')
println findAllPropertiesForClassWithAnotation(a, MyAnnot)
Mind that passing only a class of annotation is not sufficient, since you don't know the methods (used and type) to be invoked on the annotation. The following method will work only for MyAnnot class.