On Sep 17, 8:35 pm, "timothy ma and constance lee" <timco...@shaw.ca>
wrote:

Try using a Set (probably HashSet or LinkedHashSet depending).  You'll
have to make sure that your object properly implements hashCode() and
equals(), but that shouldn't be too hard...

Also, please don't top post.

4. It makes it hard to follow the conversation.
3. Why is top-posting bad?
2. Please don't top post.
1. I like to top post.

Good luck,
Daniel.

...

Please refrain from top-posting.  I find it most confusing.
Notice how both Roedy and myself put our comments
directly after anything worth replying to?  In best situations,
we would then trim other parts of earlier messages that
we are not commenting on.  That technique is known as
'in-line with trim' posting - and is much easier to follow.

OK.  So I was wrong in guessing that the Acc./Seq. #
was unique in all cases - they can also be duplicate.

I suspect (without looking at the link Roedy posted)
that sorting the records is one technique that might
identify duplicates, but there are also other ways.

For example, you might iterate the entire original list
and on each iteration of the loop.
- Make an object that uses all the fields as a 'key'
- Use that  key to check if a record with that key
already exists in a HashMap.
- If not..
  - add the object to the HashMap,
..else..
 - discard it as a duplicate.

At the end of the loop, the HashMap should contain
only the unique records.

How do you receive the message?

If your records comes from the SQL database, you may simply achieve your
goal using "SELECT DISTINCT ... " instead of a regular "SELECT ..."
statement.

If there are some additional data being read with an SQL query, there is
usually also possibility to read the rows in order which is consistent
(partially at least) with your uniqueness key.  Because database keys
are usually already indexed, it should cost nothing if you'll choose
your database keys in ORDER BY clause to achieve the right order.
Having even partially sorted records at Java side you may significantly
seed up your process (of course, if it all is really worth of it).

Otherwise, just follow some of the already suggested solutions.

piotr

"timothy ma and constance lee" <timcons1@shaw.ca> wrote in news:_HHHi.194784
$fJ5.28279@pd7urf1no:

Questions:

1.  do you already have a Java object that encapsulates a record of data?  If
not, can you implement one?

2.  does this Java object implement java.lang.Comparable?  If not, can it be
made to do so?

3.  if you have two duplicate records in the sequence of records, would you
rather end up (after you do your processing to remove duplicates) wiht the
first record, or would you rather end up with the last record of the
duplicates?

Suggestion:

use a java.util.Set of objects (that must implement Comparable) to eliminate
duplicates.  When you've added all of your collection of record objects to
the Set, you will end up with a collection with no duplicates.

Regards
GRB