Tomcat7 MySQL connector inconsistency

Question

This is a bit of a weird one question and I cannot for the life of figure out what's going on. I have two applications (WARS) running on a Tomcat7 instance. Both of them connect to a database and get that connection using JNDI. The datasource reference specified in the tomcat context.xml file as follows.

Tomcat7/conf/context.xml

<Resource name="jdbc/dataSourceOne" auth="Container" type="javax.sql.DataSource" maxActive="100" maxIdle="30" maxWait="10000" username="user" password="pass" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost/databaseone" />

<Resource name="jdbc/dataSourceTwo" auth="Container" type="javax.sql.DataSource" maxActive="100" maxIdle="30" maxWait="10000" username="user" password="pass" driverClassName="com.mysql.jdbc.Driver"  url="jdbc:mysql://localhost/databasetwo" />

WEB-INF/lib

Both applications have a copy of the mysql connector jar in their lib folders.

• mysql-connector-java-5.1.34.jar

Now here's where it gets weird, application 1 works straight out of the box. I just need to deploy the WAR on my tomcat instance and it's all systems go. It gets its datasource and can connect to it's database with absolutely no problems.

However, when I try and deploy application 2, I get a MySQL class not found exception. Now the fix for this is to add the above mysql connector jar to the tomcat7/lib folder.

My question is why do I need only need to add this for my second application? If tomcat7 requires the mysql connector jar why does my first application work without any modification to the tomcat7 setup at all?

It just doesn't make sense that one application will work but the other won't without the modification.

Any help would be greatly appreciated folks.

Answer 1

@Gimby - Turns out you were right, application 1 wasn't actually using the datasource defined in tomcats context.xml file. Thanks for the input, really appreciate the help.