I'm attaching my context configuration file (CCF) that I use with Tomcat-4.1.x. It works perfectly for me. If you are using Tomcat-4.1.x, you can put both your context directory and the attached CCF (modified to your needs) in TOMCAT_HOME/webapps. Or, you can add the <Context> inside the CCF to your server.xml if you are using Tomcat-4.0.x. The configuration for your web.xml and the syntax of how you access your datasource using Java code is commented out inside the CCF for your reference.
BTW, make sure you put your DB Driver in TOMCAT_HOME/common/lib because both your server and your app need access to the driver.
Also, if you try using Tomcat-4.1.7, DBCP doesn't seem to work (at least not for me) with the commons-dbcp.jar that comes with it. I copied the commons-dbcp.jar from Tomcat-4.1.3 over the one in 4.1.7 and things started working again. Hopefully that is fixed by the next release.
I can't tell you much about using DBCP with Tomcat-4.0.x. One thing I'd recommend, though, is upgrading to, at least, Tomcat-4.0.4. Many, many important bugs are fixed including some classloading bugs. What I really recommend is moving to Tomcat-4.1.7 and using the DBCP workaround I mentioned above. The DBCP issue was the only thing I've found not working as I expected. It is a very stable release from what I can tell.
Good luck!
Jake
At 03:36 PM 7/12/2002 -0400, you wrote:
Hello -
I'm having problems getting a connection to my database using JNDI and
various pooling mechanisms. I'm using tomcat 4.0.3 standalone on Win2K.
First, let me say that I can access my database (SQL Server 2000) using the
Microsoft JDBC Type 4 driver without any problems if I put the connection
code right in my servlet (Class.forName, etc.). If I do that, no problems.
It's only when I try and move the database connection code up to an
application scope or use pooling that I run into problems. I've setup JNDI
according to the Jakarta-Tomcat HOW-TO.
I've tried DBCP/pool according to this link:
http://marc.theaimsgroup.com/?l=tomcat-user&m=102225547106556&w=2
I also tried the solution from here:
http://developer.java.sun.com/developer/onlineTraining/Programming/JDCBook/c
onpool.html
And I also tried the DBConnectionBroker from javaexchange.com, as well as
the DataSourceWrapper/ConnectionPool classes from the O'Reilly JSP book.
I've even tried setting up DriverName, URL, username, and password as
servlet parameters in web.xml and writing an "init" servlet that would read
them in, create the datasource, and then push the datasource into the
application scope with getServletContext().setAttribute(). That didn't
work, either.
I would definitely appreciate any help or suggestions, I'm going crazy
trying to figure out what is wrong. I don't really even need the pooling,
but what I want to do is get the specific database parameters (username,
password, host, etc.) OUT of the servlets (and beans). I want other
developers to just be able to grab a handle to the datasource, open a
connection, and use it without having to know any specific information about
the database and the parameters.
Here's my server.xml (with the DBCP/pool) setup:
<Resource name="jdbc/MyTestDB" auth="Container" type="javax.sql.DataSource"
/>
<ResourceParams name="jdbc/MyTestDB">
<parameter>
<name>factory</name>
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>
<parameter><name>maxActive</name><value>100</value></parameter>
<parameter><name>maxIdle</name><value>30000</value></parameter>
<parameter><name>maxWait</name><value>100</value></parameter>
<parameter>
<name>user</name>
<value>some_user</value>
</parameter>
<parameter>
<name>password</name>
<value>some_password</value>
</parameter>
<parameter>
<name>databasename</name>
<value>some_db</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>com.microsoft.jdbc.sqlserver.SQLServerDriver</value>
</parameter>
<parameter>
<name>url</name>
<value>jdbc:microsoft:sqlserver://SOMEHOST:1433;User=some_user;Password=some
_password;DatabaseName=some_db</value> -->
</parameter>
</ResourceParams>
Here is my web.xml:
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/MyTestDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
In every case above, regardless of the pooling mechanism, or even just
trying to setup a datasource as an application scope object, I get either an
error message, or null. In the config above, I get null. The code I use
with the config above looks like this:
As a test, I wrote a little JNDI reader servlet that just enumerates over
the JNDI space and lists out the objects:
try {
Context initCtx = new InitialContext();
NamingEnumeration enum = initCtx.listBindings("java:comp/env/jdbc");
while (enum.hasMore()) {
Binding binding = (Binding) enum.next();
out.println("Name: " + binding.getName() + "<br>");
out.println("Type: " + binding.getClassName() + "<br>");
out.println("Value: " + binding.getObject() + "<br>");
out.println();
out.println();
}
} catch (NamingException e) {
out.println("Naming Exception: " + e.getMessage());
}
When I run this servlet, I get output that says:
Name: MyTestDB
Type: org.apache.naming.ResourceRef
Value: Reference Class Name: javax.sql.DataSource Type: description Content:
DB Connection Type: scope Content: Shareable Type: auth Content: Container
Now, I'm no expert by any means, but it seems to me that things are setup
correctly, though I realize my JNDI reader servlet is just reading web.xml.
JNDI knows what's up, or seems to, but for some reason I can't get a valid
DataSource to my database.
Any thoughts? Suggestions? I can't switch databases, and I can't buy
another Type 4 driver (the Microsoft driver is free), nor can I use the
JDBC-ODBC bridge. Any help is appreciated!!
- John
============================================
John Turner
[EMAIL PROTECTED] | 248-488-3466
Advertising Audit Service
http://www.aas.com
- John
============================================
John Turner
[EMAIL PROTECTED] | 248-488-3466
Advertising Audit Service
http://www.aas.com
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