获取泛型map工具类

public static Map<String, Type> getGenericMap(Type paramType) {
    Type type = resolveType(paramType);
    if (type instanceof ParameterizedTypeImpl) {
        ParameterizedTypeImpl ty = (ParameterizedTypeImpl) type;
        final Class<?> rawType = ty.getRawType();
        return Steam.of(rawType.getTypeParameters()).map(Type::getTypeName)
                .zip(Steam.of(ty.getActualTypeArguments()), Maps::entry)
                .collect(Collective.entryToMap(LinkedHashMap::new));
    }
    return new HashMap<>();
}

private static Type resolveType(Type paramType) {
    Type type;
    for (type = paramType;
         type instanceof Class;
         type = ((Class<?>) type).getGenericSuperclass()) {
        if (Object.class.equals(type)) {
            Type[] genericInterfaces = ((Class<?>) type).getGenericInterfaces();
            if (genericInterfaces.length > 0 && Objects.nonNull(genericInterfaces[0])) {
                type = genericInterfaces[0];
            }
        }
    }
    return type;
}

@Test
void testGetGenericMap() {
    final Map<String, Type> genericMap = ReflectHelper.getGenericMap(new HashMap<String, TreeMap<String, Object>>() {
    }.getClass());
    Assertions.assertEquals(String.class, genericMap.get("K"));
    Assertions.assertEquals(ParameterizedTypeImpl.make(TreeMap.class, new Type[]{String.class, Object.class}, null), genericMap.get("V"));
}