Unfortunately, my host doesn't support it. Next time I will if I ever get this finished! ----- Original Message ----- From: "V. Cekvenich" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, September 29, 2002 9:59 PM Subject: Re: JDBC Connection pool sample code; was Re: Best practices for Tomcat and server load
> OT: > Conside postgreSQL! It is FREE, ansi SQL compliat, etc. etc. > > Bill Blackmon wrote: > > Thanks - all of the DAO classes are static. I don't think that is the > > immediate problem. I'm having > > a concurrent list modification that occurs on a single record. Since there > > are no nested select statement > > in MySQL, I'm having to use a lot of list and select statements. It really > > sucks.....I just have to track down > > the bug and re-evaluate some other things. Quickly....:) > > ----- Original Message ----- > > From: "V. Cekvenich" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Sunday, September 29, 2002 8:49 PM > > Subject: JDBC Connection pool sample code; was Re: Best practices for Tomcat > > and server load > > > > > > > >>A FAQ is what is good practice for JDBC connection pooling and how to > >>use it with Java Beans. > >> > >>My Ans, with working source code: > >> > >>(A good practices is: a property that has a getter/setter in a bean, and > >>a bean has a DAO it delegates to.) > >> > >>You could have a DAO with a class/static initialize that gets the data > >>source/connection pool > >>I do not like philosophical answers so here is a code sample, note use > >>of static, hence done once to get a handle on the data source/connection > >>pool: > >> > > > > http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/basicPortal_07/sr > > c/org/commons/DAO/BasicDAOImpl.java?rev=1.1.1.1&content-type=text/vnd.viewcv > > s-markup > > > >>It uses DBCP from Jakarta commons connection pool, but you get the point > >>of how to use a static class initialize to get a handle to a data source > >>so you can look up the data source once, and then just dish out > > > > connection. > > > >>Also I use rowset over resultset, which makes it very easy to close, and > >>destroy, unlike resultset. (con.close,rs.close, stmnt.close in finaly, > >>plus it loses data on a connection disconect) > >>Rowset also does reduces need for GC generated by VO/DTO and > >>collections, since a disconnected rowset has the values. I use an open > >>source rowset from sourceforge called jxutil. > >> > >>hth, > >>V. > >> > >>ps: Consider doing MVC, hence each layer is unit testable, such as a > >>bean that delegates to DAO interface, which above also enables, as well > >>as enabling you to change the implemenentation of the DAO. > >> > >>ps2: Answer to what is the most popular hands on training class and who > >>teaches it? > >>http://www.mail-archive.com/mvc-programmers%40basebeans.com/msg00242.html > >> > >>Also, at basicPortal.sf.net you can download for free a 350 page book a > >>bit more advanced that talks about db quite a bit. > >> > >> > >> > >>Bill Blackmon wrote: > >> > >>>I'm getting complaints from my host about excessive CPU usage in my web > >> > > app. > > > >>>I'm unable to use > >>>connection pooling in the servers environment so I'm using a new > >> > > connection > > > >>>for each DB call (and > >>>there are quite a few). The connections are promptly closed afterwards. > >> > > Is > > > >>>it a better idea to use a > >>>connection for each session and check to see if its still valid each > >> > > time it > > > >>>is needed? There are many lookup lists > >>>maintained in sessions as ArrayLists. Should those be made > >>>application-level? I also have a number of static > >>>factory classes that perform database/business logic. Should those be > >> > > made > > > >>>into Singletons? What is a good monitoring tool > >>>for development on Win2000? The server is Linux but I have no way of > >> > > seeing > > > >>>how big the load is....any help > >>>would be greatly appreciated. > >>> > >>>Thanks, > >>>Bill > >> > >> > >> > >> > >>-- > >>To unsubscribe, e-mail: > > > > <mailto:[EMAIL PROTECTED]> > > > >>For additional commands, e-mail: > > > > <mailto:[EMAIL PROTECTED]> > > > > > > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
