Thanks a lot. I've fellow your guide and fixed the issue well.
Daniel Dekany <[email protected]> 于2019年11月1日周五 下午7:33写道：
> TemplateDirectiveModel (and TemplateMethodModelEx) gets values as
> TemplateModel-s, so they behave similarly to the template language. (The
> template language treats objects according TemplateModel interfaces they
> implement, not based on their "original" type, if they had an original type
> at all.) Now, if you need to get back the original object, then you need to
> unwrap it, like this:
>
> // Let's assume we know that param is not null.
> Object unwapped;
> if (param instanceof AdapterTemplateModel) {
> unwrapped = ((AdapterTemplateModel) tm).getAdaptedObject(Object.class);
> } else {
> // Fail as it's not the expected type
> ...
> }
>
> if (!(unwrapped instanceof ClassDescription)) {
> // Fail as it's not the expected type
> ...
> }
> ClassDescription cls = (ClassDescription) unwrapped;
>
>
> You can write a static utility method that does this easily. There's no
> such utility method in FreeMarker sadly... yet. Well, DeepUnwrap.unwrap is
> similar, but an overkill on one hand, and doesn't check for the expected
> class on the other.
>
> On Fri, Nov 1, 2019 at 3:49 AM Joson Choo <[email protected]> wrote:
>
> > Hi all,
> > I'm new for freemarker. I tried to create my customized directive as
> > below but could not run it in a right way:
> >
> >
> > public class TypeSimpleNameDirective implements TemplateDirectiveModel {
> >
> > private static final String PARAM_CLAZZ = "clazz";
> >
> > @Override
> > public void execute(Environment env, Map params, TemplateModel[]
> > loopVars, TemplateDirectiveBody body) throws TemplateException,
> > IOException {
> > // Check if no parameters were given:
> > if (!params.containsKey(PARAM_CLAZZ)) {
> > throw new TemplateModelException(
> > "typeSimpleName required parameter clazz.");
> > }
> > if (!(params.get(PARAM_CLAZZ) instanceof ClassDescription)) {
> > throw new TemplateModelException(
> > "clazz should be a instance of ClassDescription but " +
> > ClassUtils.getShortClassName(params.get(PARAM_CLAZZ), "null") + " is
> > given.");
> > }
> > ClassDescription cls = (ClassDescription) params.get(PARAM_CLAZZ);
> > ......
> > }
> >
> >
> > And then I used it like this:
> >
> > <@typeSimpleName clazz=api.returnType></@typeSimpleName>
> >
> > The api.returnType is ClassDescription.
> >
> > Then it threw an error:
> >
> > > clazz should be a instance of ClassDescription but StringModel is
> given.
> >
> >
> > Any help is appreciated.
> >
>
>
> --
> Best regards,
> Daniel Dekany
>
