You're saying that the spec doesn't say anything about this;
how comes you then say that the behavior of Tomcat is the
correct one?...
Thx,
-- Oliver
Hans Bergsten wrote:
>
> Oliver Suciu wrote:
>
> > Hi,
> >
> > Can anybody help clarify how a JSP container should handle
> > overloaded setters in a custom tag:
> >
> > public void setData(List dataList) {
> > this.dataList = dataList;
> > }
> > public void setData(Object dataObj) {
> > this.dataObj = dataObj;
> > }
> > public void setData(String dataStr) {
> > this.dataStr = dataStr;
> > }
> >
> > We want to give the JSP author the convenience of passing data
> > to a tag using different types, whichever comes in more handy.
> > The data would be of the same "logical" kind, that's why, ideally,
> > the setters would bear the same name, just like overloaded methods
> > in Java.
> >
> > As an example, JRun 3.1 accepts the code above, whereas Tomcat
> > 3.2.3 throws a CompileException ("Unable to convert a String
> > to java.util.List").
> >
> > What's the correct behavior?
>
> Tomcat's behavior is correct. When it comes to attribute setter
> methods, a tag handler class is a "bean", so you must go to the
> bean spec to see how it deals with property setter methods.
> The spec text itself doesn't say anything about multiple setter
> methods, but the implementation of the methods that deal with
> setter methods only allow one setter method per property. Hence,
> multiple setter methods for a tag handler attribute is not
> allowed.
>
> In JSP 1.2 you can get around this by making the type of the
> attribute Object, and the figure out which specific type you
> got. The reason this only works well with JSP 1.2 is that
> JSP 1.1 doesn't accept a string literal as the attribute
> value for an attribute of type Object; JSP 1.2 does.
>
> public void setData(Object data) {
> this.data = data;
> }
>
> public int doStartTag() {
> if (data instanceof List) {
> // Work with it as a List
> }
> else (data.getClass().isArray()) {
> // Work with it as an array
> }
> else (data instanceof String) {
> // Work with as a String
> }
> else ...
> }
>
> I describe this in more detail in an article that will soon
> be published at the O'Reilly site. I'll post the URL here
> when it's available.
>
> Hans
> --
> Hans Bergsten [EMAIL PROTECTED]
> Gefion Software http://www.gefionsoftware.com
> Author of JavaServer Pages (O'Reilly), http://TheJSPBook.com
>
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