Re: [weld-dev] Overridden equals() are ignored on client proxy
by Martin Kouba
Hi Emily,
yes, the spec is clear and for good reasons. This was already discussed
in EG and weld community - see for example WELD-695 [1]. And the
consensus is: "it does not make sense to delegate equals/hashcode to
bean instances for client proxies".
One of the problems is that client proxies may be shared between
multiple injection points (and in Weld they are).
Also in Weld a client proxy is equal to a client proxy for the same bean.
Anyway, it seems it doesn't work on OWB either - see also OWB-458 [2].
Martin
[1]
https://issues.jboss.org/browse/WELD-695?focusedCommentId=12566720&page=c...
[2]
https://issues.apache.org/jira/browse/OWB-458
Dne 3.12.2015 v 00:43 Emily Jiang napsal(a):
> Hi Martin,
>
> For some reason, a proxied bean's equals cannot be called. Are you aware
> of this problem? Although the spec says:
>
> The behavior of all methods declared by java.lang.Object, except for
> toString(), is
> undefined for a client proxy. Portable applications should not invoke
> any method declared by
> java.lang.Object, except for toString(), on a client proxy.
>
> I thought the overridden equals is different from the methods defined by
> Object class and it should be invoked.
>
> Please find attached a very simple test case that shows a .equals()
> method not being invoked on a bean proxied by Weld.
>
>
> In a debugger one can see that GenericBean.equals() is not invoked
> within the Servlet:
>
> protected void doGet(HttpServletRequest request,
> HttpServletResponse response) throws ServletException, IOException {
> PrintWriter pw = response.getWriter();
> pw.println ("Hello");
> if (gb.equals(new GenericBean(10))) { // GenericBean.equals() is
> not invoked; test prints 'fail'
> pw.println("pass");
> } else {
> pw.println ("fail");
> }
> }
>
> The .war contains source and object code. As you can see there's only
> two classes.
>
> Many thanks,
> Emily
> ===========================
> Emily Jiang
> WebSphere Application Server, CDI Development Lead
>
> MP 211, DE3A20, Winchester, Hampshire, England, SO21 2JN
> Phone: +44 (0)1962 816278 Internal: 246278
>
> Email: emijiang(a)uk.ibm.com
> Lotus Notes: Emily Jiang/UK/IBM@IBMGB
> Unless stated otherwise above:
> IBM United Kingdom Limited - Registered in England and Wales with number
> 741598.
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
>
--
Martin Kouba
Software Engineer
Red Hat, Czech Republic
10 years
Overridden equals() are ignored on client proxy
by Emily Jiang
Hi Martin,
For some reason, a proxied bean's equals cannot be called. Are you aware
of this problem? Although the spec says:
The behavior of all methods declared by java.lang.Object, except for
toString(), is
undefined for a client proxy. Portable applications should not invoke any
method declared by
java.lang.Object, except for toString(), on a client proxy.
I thought the overridden equals is different from the methods defined by
Object class and it should be invoked.
Please find attached a very simple test case that shows a .equals() method
not being invoked on a bean proxied by Weld.
In a debugger one can see that GenericBean.equals() is not invoked within
the Servlet:
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
PrintWriter pw = response.getWriter();
pw.println ("Hello");
if (gb.equals(new GenericBean(10))) { //
GenericBean.equals() is not invoked; test prints 'fail'
pw.println("pass");
} else {
pw.println ("fail");
}
}
The .war contains source and object code. As you can see there's only two
classes.
Many thanks,
Emily
===========================
Emily Jiang
WebSphere Application Server, CDI Development Lead
MP 211, DE3A20, Winchester, Hampshire, England, SO21 2JN
Phone: +44 (0)1962 816278 Internal: 246278
Email: emijiang(a)uk.ibm.com
Lotus Notes: Emily Jiang/UK/IBM@IBMGB
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
10 years