I have a problem with giving the tag a default value.
When I created a .jsp file as follow,
You can also set the defaul text in the Model as well. Your jsp would have:
and then in the Model, you'd have:
private static final String DEFAULT_textareacontent = "Hello World";
private String my-text-box = DEFAULT_textareacontent;
Not sure if this is a best practice or not, but it seems to work for me.