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  1. import java.lang.reflect.Field;
  2. import java.lang.reflect.ParameterizedType;
  3. import java.lang.reflect.Type;
  4.  
  5. enum Test {
  6.     TEST1,
  7.     TEST2,
  8.     TEST3
  9. }
  10.  
  11. class Ideone {
  12.  
  13.     private Test directEnumTypeReference;
  14.     private Enum<Test> baseEnumTypeReference;
  15.  
  16.     public static void main(String[] args) throws NoSuchFieldException {
  17.         Ideone ideone = new Ideone();
  18.         ideone.directEnumTypeReference = Test.TEST1;
  19.         ideone.baseEnumTypeReference = Test.TEST2;
  20.  
  21.         Class directEnumClass = getEnumType("directEnumTypeReference");
  22.         ideone.directEnumTypeReference = (Test) Enum.valueOf(directEnumClass, "TEST3");
  23.  
  24.         Class baseGenericTypeClass = getEnumType("baseEnumTypeReference");
  25.         ideone.baseEnumTypeReference = Enum.valueOf(baseGenericTypeClass, "TEST3");
  26.  
  27.         System.out.println(ideone.directEnumTypeReference);
  28.         System.out.println(ideone.baseEnumTypeReference);
  29.  
  30.     }
  31.  
  32.     private static Class<?> getEnumType(String fieldName) throws NoSuchFieldException {
  33.         Field field = Ideone.class.getDeclaredField(fieldName);
  34.         Type genericFieldType = field.getGenericType();
  35.         Class<?> enumType;
  36.  
  37.         // Handles Enum<Test>
  38.         if (genericFieldType instanceof ParameterizedType) {
  39.             ParameterizedType parameterizedType = (ParameterizedType) genericFieldType;
  40.             Type actualTypeArgument = parameterizedType.getActualTypeArguments()[0];
  41.             enumType = (Class) actualTypeArgument;
  42.         }
  43.         // Handles Test
  44.         else {
  45.             enumType = field.getType();
  46.         }
  47.  
  48.         return enumType;
  49.     }
  50. }
Success #stdin #stdout 0.04s 2184192KB
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Standard input is empty
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TEST3
TEST3
https://ideone.com/Zz9ThC
https://pt.stackoverflow.com/q/392288/100
language:
Java (HotSpot 12)
created:
4 years ago
visibility:
secret

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