Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.java.programmer > #18437

Question about HashMap and Map.Entry ...

From Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at>
Newsgroups comp.lang.java.programmer
Subject Question about HashMap and Map.Entry ...
Date 2012-08-30 17:39 +0000
Organization A noiseless patient Spider
Message-ID <slrnk3v9ba.u9l.avl@gamma.logic.tuwien.ac.at> (permalink)

Show all headers | View raw


Given a (Hash)Map<Long,Long> map and two Long values k and v,
Some task is to see if k is already in the map, and only if so,
then update the value in the map based on previous value and v.

Of course, that is trivial, and I've already implemented
it with containsKey(), get() and put().

It's just, that it seems to me that my piece of code
could be a bit *clearer*, if I could obtain the Map.Entry
for "k", and (if that isn't null) do getValue() and
setValue(...) on the Entry.

What I'm missing, however, is:
  How would I get the Entry for a given key?
(apart from scanning all through the entrySet())

PS: using 1.6, but also interested in future (i.e. 1.7 or 
   even newer) prospects, and also in (any) explicit reasons
   for *not* having some map.getEntry(K k).
   Also, such an Entry should be tied to the Map just like
   those in the entrySet().  NavigableMap has methods that
   return Entries with "snapshot"-semantics, which is *not*
   what I'm looking for.

Back to comp.lang.java.programmer | Previous | NextNext in thread | Find similar | Unroll thread


Thread

Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-30 17:39 +0000
  Re: Question about HashMap and Map.Entry ... markspace <-@.> - 2012-08-30 10:46 -0700
    Re: Question about HashMap and Map.Entry ... Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-08-30 11:15 -0700
      Re: Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-30 19:24 +0000
        Re: Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-30 19:32 +0000
          Re: Question about HashMap and Map.Entry ... Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-08-30 13:08 -0700
            Re: Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-30 21:55 +0000
              Re: Question about HashMap and Map.Entry ... Robert Klemme <shortcutter@googlemail.com> - 2012-08-31 07:27 +0200
                Re: Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-31 10:26 +0000
                Re: Question about HashMap and Map.Entry ... Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-08-31 11:22 -0700
                Re: Question about HashMap and Map.Entry ... Robert Klemme <shortcutter@googlemail.com> - 2012-09-01 11:06 +0200
        Re: Question about HashMap and Map.Entry ... markspace <-@.> - 2012-08-30 14:30 -0700
          Re: Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-30 22:42 +0000
        Re: Question about HashMap and Map.Entry ... markspace <-@.> - 2012-08-30 14:34 -0700
  Re: Question about HashMap and Map.Entry ... Lew <lewbloch@gmail.com> - 2012-08-30 13:42 -0700
    Re: Question about HashMap and Map.Entry ... Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-08-30 22:34 +0000

csiph-web