I'm developing my first ever servlet for Tomcat 6.0.18 under Mac OS X
10.5.6 with Java 1.5.0_16. I've used Tomcat a lot with Cocoon and I
know Java reasonably well.
I'd like to extend the standard WebdavServlet that comes with Tomcat
to access data from a relational database using JDBC. I've started to
write a DirContext (called DBDirContext) to do this. I've written a
test servlet
public class DBServlet extends WebdavServlet {...}
and filled it with methods which print out a message and invoke their
super methods:
... xxx(...) {
System.out.println("some text");
super.xxx(...);
}
i.e. I just want a trace on standard output of what WebDAV calls so I
know what bits of DBDirContext to develop next.
My Tomcat is as installed by NetBeans 6.5, that is with a separate
CATALINA_HOME and CATALINA_BASE. I have discovered that my
DBDirContext and supporting database stuff is not found if I include
it in the WAR file deployed into $CATALINA_BASE/webapps, so I modified
$CATALINA_BASE/conf/catalina.properties to make common.loader look
also in $CATALINA_BASE/common/lib and I put DBDirContext and
supporting cast into there.
If I put the following file into META-INF/context.xml, I can call
DBServlet over an HTTP session and successfully mount a WebDAV disk
using the filesystem:
<Context>
<Resource name="jdbc/xwdb" auth="Container"
type="javax.sql.DataSource"
driverClassName="org.postgresql.Driver"
url="..."
username="..." password="..." maxActive="20" maxIdle="10"
maxWait="-1"/>
</Context>
All of my output to standard output appears in the log.
However, when I include <Resources... /> to pull in DBDirContext as
follows, WebDAV gets as far as an initial OPTIONS method and gives up:
<Context>
<Resources className="org.vimia.xw.db.dircontext.DBDirContext" />
<Resource name="jdbc/xwdb" auth="Container"
type="javax.sql.DataSource"
driverClassName="org.postgresql.Driver"
url="..."
username="..." password="..." maxActive="20" maxIdle="10"
maxWait="-1"/>
</Context>
The trace I built in does not appear on standard output in this case.
Examining the response to the OPTIONS method, I see that WebDAV
generates a response from doOptions in HttpServlet and not from the
overriding one in WebdavServlet.
So WebdavServlet and my DBServlet seem to be being ignored. I don't
understand why and I'd be grateful if someone could give me some
pointers. The Tomcat documentation suggests that changing the
<Resources .../> to something other than the filesystem results in
Tomcat not being able to read files it needs: does this include my JAR
files? If so, do I have to make a hybrid DBDirContext that gets the
files Tomcat needs from the filesystem and the data I want from the
database?
Steve
