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From Chiradeep Vittal <Chiradeep.Vit...@citrix.com>
Subject Re: [DISCUSS]null pointer returned from daoimpl
Date Fri, 07 Feb 2014 22:37:39 GMT
There is no good answer IMHO. The designer of the API chose this design.

Throwing a checked exception or returning Null is equivalent.
Throwing a runtime exception is probably wrong since there may be some
recovery possible.

We could annotate the method with @Nullable so that the compiler/IDE can
warn if the caller of the API forgets to check for Null.

On 2/7/14 2:30 AM, "Daan Hoogland" <daan.hoogland@gmail.com> wrote:

>LS,
>
>in PrivateIpDaoImpl a null pointer is returned when no db object can be
>found:
>
>    @Override
>    public PrivateIpVO allocateIpAddress(long dcId, long networkId,
>String requestedIp) {
>...
>        PrivateIpVO  vo = lockOneRandomRow(sc, true);
>        if (vo == null) {
>            txn.rollback();
>            return null;
>        }
>...
>        return vo;
>    }
>
>I would expect it to throw a ClodException of some sort and would like
>to change it to that but recognize that the null pointer could be of
>significance in cases. Is there a policy on how dao's should return
>failures?
>
>In my opinion a null should never be returned by a dao, at most a vo
>containing a null but this seldom makes sense.
>
>-- 
>Daan


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