Old jdbc chestnut

Question

Hi
Have been happily developing struts apps with Netbeans 4 recently. Today something exploded with an out of memory error and despite system restarts and reinstallations none of my web applications can find the jdbc drivers!
I have put these in common/lib as per tomcat 5 instructions and used the following xml snippets..
context xml
<Resource name="jdbc/researchDB" auth="Container" type="javax.sql.DataSource"/>
<ResourceParams name="jdbc/researchDB">
<parameter>
<name>factory</name>
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>oracle.jdbc.OracleDriver</value>
</parameter>
<parameter>
<name>username</name>
<value>****</value>
</parameter>
<parameter>
<name>password</name>
<value>*****</value>
</parameter>
<parameter>
<name>url</name>
<value>jdbc:oracle:thin:@127.0.0.1:1521:research</value>
</parameter>
<parameter>
<name>maxActive</name>
<value>20</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>10</value>
</parameter>
<parameter>
<name>maxWait</name>
<value>10000</value>
</parameter>
</ResourceParams>
web.xml
<resource-ref>
<description>Research DB connection</description>
<res-ref-name>jdbc/researchDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
protected Connection getConnectionFromDataSource(DataSource dataSource) throws SQLException
Connection connection = dataSource.getConnection();**exception thrown here
if( connection == null )
throw new SQLException("DataSource not initialised.");
return connection;
The context seems to be setup okay - in the code snippet above the exception reads
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
     at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:780)
     at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
     at AbstractRelationalDAO.getConnectionFromDataSource(AbstractRelationalDAO.java:33)
     at UserDAO.getUser(OracleEmisUserDAO.java:26)
     at actions.LogonAction.execute(LogonAction.java:46)
     at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
     at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
"cannot create jdbc connection"...emm, seems very odd how working code can transform, maybe Netbeans 4 is to be avoided :-)
anyway above suggests that my xml entries aren't being picked up - anyone any ideas why this should be?
many thanks
Stephen

Answer 1

Emm, got things working again by reinstalling. Seems that there is a more sinster problem with Tomcat 5.5. I noticed that my web.xml file is not correct against the schema and similarly for context.xml.
Will investigate further and try to get Tomcat 5.5 version running. Maybe it is a problem with the servlet spec levels?
Anyway watch out for Netbeans 4 - I found someone else with a similar problem - after a crash the internal tomcat can behave differently - for example by requesting the manager uname/pwd when running the internal tomcat.
Stephen
Hi
Have been happily developing struts apps with
Netbeans 4 recently. Today something exploded with an
out of memory error and despite system restarts and
reinstallations none of my web applications can find
the jdbc drivers!