My last post dealt with Websphere configuration for Hibernate with a Datasource for MySQL. I also mentioned how I typically use Apache Tomcat to do a lot of my testing before deploying to Websphere. Smart readers will know that the types of applications I am referring to do not include JMS or EJBs but are straight Servlet or Web Services type apps. Development and Testing for full J2EE based applications should take place using other Application Servers, and or development environments.
With that said, I thought I would post the steps I went through to configure Tomcat for a Datasource, and what I had to do to configure my Hibernate configuration file for that source.
First off, I made no changes to my hibernate.cfg.xml from the one I deployed to Websphere. So the following configuration parameters are still the same.
<property name=”current_session_context_class”>thread</property>
<property name=”hibernate.bytecode.use_reflection_optimizer”>false</property>
<property name=”hibernate.connection.datasource”>java:comp/env/jdbc/mysqlblogpostdataref</property>
<property name=”show_sql”>true</property>
<property name=”dialect”>org.hibernate.dialect.MySQLDialect</property>
<property name=”hibernate.bytecode.use_reflection_optimizer”>false</property>
<property name=”hibernate.connection.datasource”>java:comp/env/jdbc/mysqlblogpostdataref</property>
<property name=”show_sql”>true</property>
<property name=”dialect”>org.hibernate.dialect.MySQLDialect</property>
I also kept my web.xml the same as my deployment to Websphere.
<resource-ref>
<description>My Blog DataSource</description>
<res-ref-name>jdbc/mysqlblogpostdataref</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
Now edit your context.xml file stored in the $CATALINA_HOME/conf directory and add a Resource entry.
<Context path="/DBTest" docBase="DBTest"
debug="5" reloadable="true" crossContext="true">
<!-- maxActive: Maximum number of dB connections in pool. Make sure you
configure your mysqld max_connections large enough to handle
all of your db connections. Set to -1 for no limit.
-->
<!-- maxIdle: Maximum number of idle dB connections to retain in pool.
Set to -1 for no limit. See also the DBCP documentation on this
and the minEvictableIdleTimeMillis configuration parameter.
-->
<!-- maxWait: Maximum time to wait for a dB connection to become available
in ms, in this example 10 seconds. An Exception is thrown if
this timeout is exceeded. Set to -1 to wait indefinitely.
-->
<!-- username and password: MySQL dB username and password for dB connections -->
<!-- driverClassName: Class name for the old mm.mysql JDBC driver is
org.gjt.mm.mysql.Driver - we recommend using Connector/J though.
Class name for the official MySQL Connector/J driver is com.mysql.jdbc.Driver.
-->
<!-- url: The JDBC connection url for connecting to your MySQL dB.
-->
<Resource name="jdbc/mysqlblogpostdataref" auth="Container" type="javax.sql.DataSource"
maxActive="100" maxIdle="30" maxWait="10000"
username="dbuser" password="yourpassword" driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/yourdatabase"/>
</Context>
The key here is to make sure your resource name in the context.xml matches your reference name in the web.xml, this is the only way Tomcat environments know how to map resources from your deployment descriptor to the context.xml.
