Hello -
I have a DB2-backed legacy app on a legacy platform that I'm trying to
modernize. My objective is to modernize the platform underneath the app
(Gentoo Linux for now, Tomcat 6.0.26, Sun JDK 1.6.0.20) and do so in a
way that a longtime Java/Tomcat integrator would readily recognize (I'm
not one). App uses Hibernate and c3p0; Hibernate is packaged in the
app's war but c3p0 is not; I've installed c3p0 through Gentoo's usual
package management system. I've also brought in the jar for the proper
version of IBM DB2 JDBC driver and its corresponding "license jar" to
match the DB2 instance version (versioning between DB2 and JDBC driver
are tightly coupled).
On the legacy Tomcat 5.0 / JDK 1.5 platform, the database connection
configuration info is handled in a seemingly customized way - something
to do with virtual hosts. At the top of the Tomcat-instance-wide
server.xml file is this structure:
<!DOCTYPE web-app[
<!ENTITY vhosts SYSTEM "vhosts.xml">
]>
But for now, I'm not interested in dealing with any kind of virtual host
arrangement. The impetus behind that was so that users can run two
independent sessions of the app in two separate browser tabs or windows .
In the vhosts.xml file is info that looks like it ought to belong in the
app's context.xml file. I understand that how context sections are
written have changed since 5.0 and I *think* I've got that worked out.
The app's original MANIFEST.MF file has this in it:
Classpath: WEB-INF/classes/mycapp/resource
WEB-INF/classes/myapp/resource
/tld WEB-INF/classes/elms/resource/hbm/MYAPP
So: given a working platform and after deploying the app war that I've
been given (let's call it "myapp.war"), here are the post-deploy steps
I've worked out so far:
* Create a symlink for $CATALINA_BASE/webapps/myapp/WEB-INF/lib/c3p0.jar
to where the package manager has put c3p0.jar
* Create symlinks for db2jcc.jar and db2jcc_license_cu.jar in
$CATALINA_BASE/webapps/myapp/WEB-INF/lib to where I've put them under
/usr/src
* Generate a new $CATALINA_BASE/webapps/myapp/META-INF/context.xml (see
below) and symlink $CATALINA_BASE/conf/Catalina/localhost/myapp.xml to it
* Add the following to $CATALINA_BASE/webapps/myapp/WEB-INF/web.xml,
before the closing "</web-app>":
<resource-ref>
<description>DB connection pool for MYAPP</description>
<res-ref-name>jdbc/myappqa</res-ref-name>
<res-type>com.mchange.v2.c3p0.ComboPooledDataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
I've created a context.xml that looks like:
<Context docBase="${catalina.home}/webapps/myapp" path=""
reloadable="false">
<Resource name="jdbc/myappqa"
description = "MYAPP connection pool"
auth="Container"
type="com.mchange.v2.c3p0.ComboPooledDataSource"
username="myappuser"
password="myapppassword"
driverClass="com.ibm.db2.jcc.DB2Driver"
url="jdbc:db2://mydb2server:50000/TESTDATA"
factory="org.apache.naming.factory.BeanFactory"
minPoolSize="15"
.
. <scissors of brevity applied - more parameters set>
.
/>
</Context>
I've been able to browse to the app and get a login page, but things
explode at login attempt, i.e., first attempt to access the data source.
Question 1: For this to work, do I need to add "WEB-INF/lib" to the
"Classpath:" list? There are about 80 jar files (including log4j,
ftpbean, Hibernate) in there aside from the symlinks I've added for the
c3p0, JDBC driver, and license jar files.
Question 2: In my context.xml, is that one parameter supposed to be
"driverClass" or "driverClassName"? I've seen both used seemingly for
the same purpose.
Question 3: Some customization has been done involving
hibernate.properties which I don't think is necessarily causing a
problem (its "meat" has been replaced by a reference to another file
much like server.xml), but in there I've noticed this:
<property name="hibernate.connection.pool_size">15</property>
As I understand it, setting this parameter activates Hibernate's own
connection pooler and further that Hibernate's own connection pooler is
not supposed to be used in any capacity other than learning and
testing. Does having this setting be in here mean that this app was
built (intentionally or not - likely not) to use Hibernate's connection
pooler and c3p0 end-to-end?
Thanks in advance for your opinions/assistance.
