How to tell which interface is implemented

[gimme_this_gimme_that]

Example,

If an object implements either :

javax.portlet.RenderRequest

or

javax.servlet.http.HttpServletRequest

how can I tell which it is?

I looked at obj.getClasses() no use provides a list of subclasses.
I looked at obj.getClassName() no use because it provides the
name of the concrete class not the interface.

Thanks

 

[Sudsy]

Example,

If an object implements either :

javax.portlet.RenderRequest

or

javax.servlet.http.HttpServletRequest

how can I tell which it is?

I looked at obj.getClasses() no use provides a list of subclasses.
I looked at obj.getClassName() no use because it provides the
name of the concrete class not the interface.

<snip>

Back to the books! The javadocs in this case. If you have an object
reference via the name obj then you can do the following:

Class k = obj.getClass();

Now research the Class#isAssignableFrom( Class k ) method.
Kewl, no?

 

[Michiel Konstapel]

Example,

If an object implements either :

javax.portlet.RenderRequest

or

javax.servlet.http.HttpServletRequest

how can I tell which it is?

Use instanceof:

if (object instanceof javax.portlet.RenderRequest) {
// process RenderRequest
} else if (object instanceof javax.servlet.http.HttpServletRequest) {
// process HttpServletRequest
} else {
// shouldn't happen
}

HTH,
Michiel