Groups > comp.lang.java.programmer > #10658

Re: Comparator?

Path	csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail
NNTP-Posting-Date	Sun, 11 Dec 2011 20:16:32 -0600
Date	Sun, 11 Dec 2011 18:16:31 -0800
From	Patricia Shanahan <pats@acm.org>
User-Agent	Thunderbird 1.5.0.2 (Windows/20060308)
MIME-Version	1.0
Newsgroups	comp.lang.java.programmer
Subject	Re: Comparator?
References	<jc3l8r$rj6$1@dont-email.me>
In-Reply-To	<jc3l8r$rj6$1@dont-email.me>
Content-Type	text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding	7bit
Message-ID	<8NGdnTnFTOyd-XjTnZ2dnUVZ_uGdnZ2d@earthlink.com> (permalink)
Lines	44
X-Usenet-Provider	http://www.giganews.com
NNTP-Posting-Host	70.230.194.31
X-Trace	sv3-UDSnaIYQlYJb+0GTK2qCgIO6eTESNR0d85FVSxgU1FuUM1NLkLSFMFL90xOw7AwH912dV/chNgQFY0d!3/cCWdwSp7MSrjj+0rtNARFr6gaV3y8enA5JttFY9S2qTLVkA6yGZyWZYNMMv+YtAXe3C4+TE6jV!+84CVewaS0XdmJbvmd88jQxpBBYQVVa84oStLYFT42s8hg==
X-Abuse-and-DMCA-Info	Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info	Otherwise we will be unable to process your complaint properly
X-Postfilter	1.3.40
X-Original-Bytes	2346
Xref	x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:10658

Show key headers only | View raw

Knute Johnson wrote:
> I've got a question about how to create a Comparator that I can use to 
> keep a sorted list of objects.  The sort fields would be a code that is 
> not something to be sorted directly and a String that I would want 
> alphabetical.  I would have a list of the codes and that list would be 
> in the sorted order.  What I want to do is put the data in order 
> according to the list of codes and the other String.
> 
> The codes are actually going to be a 3 letter String.  For example the 
> codes could be;
> 
> XAB
> AJC
> BQP
> RST
> 
> and the data would be a code String and another String to sort 
> alphabetically.
> 
> XAB San Francisco
> BQP Alabama
> XAB Houston
> AJC Montreal
> 
> I want the data sorted in this order:
> 
> XAB Houston
> XAB San Francisco
> AJC Montreal
> BQP Alabama
> 
> Any simple ideas on how to design the Comparator?
> 
> Thanks,
> 

I would deal with the codes by creating a Map<String,Integer>, and
initializing it to map each code to its index in the original list.

In the compare method, first compare the results of looking up the codes
in the map. If that gives equality, then compare the city name strings
to resolve the comparison.

Patricia

Thread

Comparator? Knute Johnson <nospam@knutejohnson.com> - 2011-12-11 17:26 -0800
  Re: Comparator? Patricia Shanahan <pats@acm.org> - 2011-12-11 18:16 -0800
    Re: Comparator? Knute Johnson <nospam@knutejohnson.com> - 2011-12-12 07:27 -0800
  Re: Comparator? Roedy Green <see_website@mindprod.com.invalid> - 2011-12-12 01:05 -0800
    Re: Comparator? Knute Johnson <nospam@knutejohnson.com> - 2011-12-12 07:28 -0800

csiph-web