Alan
What you are doing is singleton pattern, it makes sure
that there is only one instance of SqlMapClient
through out your application.
Ashish
--- Alan Chandler <[EMAIL PROTECTED]> wrote:
> On Monday 24 Oct 2005 16:50, Ashish Kulkarni wrote:
> > Hello
> > What is the best way to get SqlMapClient in a web
> > application
> > 1 , Define a singleton pattern class, and create a
> > instance of SqlMapClient to use by all classes
> which
> > need to access data.
> >
> > 2, Define a AbstractClass and put method to get
> > SqlMapClient in constructor of this class, and
> then
> > each class which needs to get data extends this
> class
> >
> >
> > 3, Create Instance of SqlMapClient in one of the
> init
> > servlets, and store this SqlMapClient in
> > ServletContext and pass it as one of the
> parameters to
> > all data classes
> >
> > 4, or any other method
>
> I have been following this thread without really
> understanding it.
>
> I would be interested in any comments on what I do,
> which I think is point 1
> (but I am new to Java and I am not sure I understand
> what a singleton is
> properly). In particular, I am not sure I
> understand what the potential
> Gotcha's are. Why doesn't everybody do it this way,
> it seems so SIMPLE.
>
> The reason I do this is that I am attempting to
> avoid creating a session to
> early in my application - but this has not been
> commented on in the thread at
> all.
>
> This is my basic class:
>
> package uk.org.chandlerfamily.sqlmap.famtree;
>
> import com.ibatis.common.resources.Resources;
> import com.ibatis.sqlmap.client.*;
> import java.io.Reader;
>
> public class FamtreeMap {
> private static final SqlMapClient sqlMap;
> static {
> try {
> String resource =
>
"uk/org/chandlerfamily/sqlmap/famtree/SqlMapConfig.xml";
> Reader reader = Resources.getResourceAsReader
> (resource);
> sqlMap =
> SqlMapClientBuilder.buildSqlMapClient(reader);
> } catch (Exception e) {
> e.printStackTrace();
> throw new RuntimeException ("Error
> initializing DataMap class. Cause: "
> + e);
> }
> }
> public static SqlMapClient getSqlMapInstance () {
> return sqlMap;
> }
>
> }
>
>
>
> and then whenever I want to do something with my
> database I do
>
> SqlMapClient map=FamtreeMap.getSqlMapInstance();
> try {
> map.startTransaction();
> ...
> ...
>
> --
> Alan Chandler
> http://www.chandlerfamily.org.uk
> Open Source. It's the difference between trust and
> antitrust.
>
__________________________________
Yahoo! FareChase: Search multiple travel sites in one click.
http://farechase.yahoo.com
