java - Reasons to change JPA implementation? -


i've heard people during careers have changed jpa implementation in projects, reasons?
jpa interface, , primitive, compared hibernate or toplink's own interfaces.
persistence used in daos , of stuff hidden in genericdao, whenever want switch jpa implementation, thing necessary change genericdao , use custom extensions.
why people using raw jpa implementation instead of using more comfortable interfaces of hibernate or toplink? profit changeability of implementation - right?
sorry weird questions i'm new persistence stuff.

some reasons change jpa implementation :

interesting vendor-specific features

most jpa vendors implement vendor-specific features outside jpa spec developers find convenient enough use in vendor-specific way. (ex: delete-orphan longtime hibernate-only). reason choose particular vendor, or migrate vendor.

compatiblity issues

sometimes might forced change jpa implementation due compatiblity issues.

  • for example, when migrating different java ee appserver, may find jpa implementation isn't compliant be, causing issues when configured on java ee server, forcing use built-in jpa implementation of java ee server. after all, once management has decided buy entire stack oracle or ibm, , favorite open source jpa implementation doesn't seem work on stack, bet know doing migrating :)
  • even within project, might run compatbility issues. jboss seam example integrates hibernate, , requires little setup. although possible & running toplink, can guarantee you spend more time debugging issues, , run lot more problems.

company guidelines / policies

some companies strict when comes application architecture.

it might

  • you forced use specific vendor (ex: toplink when working in oracle environment)
  • the company has policy against using open-source or non-approved libraries.

vendor and/or community support

another important 1 amount of support you'll able get, either vendor or community. implementation can have big community behind it, or commercial vendor can offer great support.

jpa spec, , in ideal world, should transparent, , shouldn't care underlying implementation being used, there vendor-specific features or issues need take account.


Comments

Post a Comment

Popular posts from this blog

Add email recipient to all new Trac tickets -

is there configuration change can made trac send notification email address upon creation of new tickets? if can't done through config, plugin second best option, source code modification last resort. note: setting smtp_always_cc in notification section of tracini send messages on updates. i'm in need of email notifications only on creation of new ticket. does have email notification? 1 option have create query list ten (or many) recently-created tickets. when looking @ results of query, use "rss feed" button @ bottom of page subscribe feed notify whenever results of query updated.
Read more

400 Bad Request on Apache/PHP AddHandler wrapper -

i'm trying create wrapper/handler called on apache server whenever requests php script inside of directory. way can authorize users entire directory or write other stuff called when directory called. this best configuration i've been able come with... <directory "/srv/http/innov/public_html"> options -indexes allowoverride order allow,deny allow directoryindex index.php </directory> then in /srv/http/innov/public_html/kb/ have .htaccess file... options -indexes addhandler auth_handler .php action auth_handler ../auth_handler.php then in /srv/http/innov/public_html/kb/auth_handler.php follows... <?php $file = $_server['path_translated']; echo $file; ?> access log: - - [02/dec/2010:17:43:15 -0500] "get /kb/index.php http/1.1" 400 590 error log: [thu dec 02 17:50:19 2010] [error] [client xxx.xxx.xxx.xxx] invalid uri in request /kb/ http/1.1 i've checked browser , seems making proper request...
Read more

php - Change action and image src url's with jQuery -

i parsing form 1 of sites using php proxy. working fine form action , img src of submit button url's relative. how can prepend full http//www.domain.com/ in front of each of url's in form? edit: here's form code once fed through new domain: <div style="display: none;" id="subscribeform" class="newform"> <h5>subscribe our newsletter</h5> <form action="/campaignprocess.aspx?listid=27057" method="post" onsubmit="return checkwholeform93426(this)" name="catemaillistform93426"> <div class="form"> <div class="item"> <label for="clfullname">full name</label> <br /> <input type="text" maxlength="255" id="clfullname" name="fullname" class="cat_textbox_small" st...
Read more