Where do I have to place the JDBC driver for Tomcat’s connection pool?

by

The JDBC driver has to be visible to the same classloader as the data source factory itself. The data source factory library is placed in Tomcat’s own /lib folder and thus loaded by Tomcat’s “common” classloader.

Your problem sounds much like that you dropped the JDBC driver in webapp’s /WEB-INF/lib. The webapp’s /WEB-INF/lib is invisible to the “common” classloader. So technically, you have to place the JDBC driver in Tomcat’s own /lib folder (or, at least, in a configurable path as specified by common.loader setting in /conf/catalina.properties) in order to make it visible to the data source factory.

Or, as you attempted, copying the data source factory into /WEB-INF/lib will also fix it. The webapp’s /WEB-INF/lib has namely higher precedence in classloading than Tomcat’s /lib folder. So if the data source factory is found in /WEB-INF/lib, it will be loaded from there. As the JDBC driver is also there, it will be seen. This is however not the right solution to your concrete problem, this is more a workaround, so you shouldn’t do this.

There isn’t exactly documentation which is specifically targeted to this issue. The Tomcat Class Loader HOW-TO will however help in understanding the class loading hierarchy in Tomcat.

screen shot showing Tomcat folder with nested "lib" folder with nested JDBC driver .jar file

See also:

More Related Contents:

  1. How to establish a connection pool in JDBC?
  2. To prevent a memory leak, the JDBC Driver has been forcibly unregistered
  3. MySQL JDBC Driver 5.1.33 – Time Zone Issue
  4. Connection pooling options with JDBC: DBCP vs C3P0 [closed]
  5. JDBC MySql connection pooling practices to avoid exhausted connection pool
  6. Closing JDBC Connections in Pool
  7. Can I connect to SQL Server using Windows Authentication from Java EE webapp?
  8. How to configure Tomcat to connect with MySQL
  9. Native Library sqljdbc_auth.dll already loaded in another classloader
  10. com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
  11. Show JDBC ResultSet in HTML in JSP page using MVC and DAO pattern
  12. Solving a “communications link failure” with JDBC and MySQL [duplicate]
  13. Deploying my application at the root in Tomcat
  14. java.sql.SQLException: – ORA-01000: maximum open cursors exceeded
  15. Cannot issue data manipulation statements with executeQuery()
  16. How to use JNDI DataSource provided by Tomcat in Spring?
  17. Increase HTTP Post maxPostSize in Spring Boot
  18. Java JDBC Access denied for user [closed]
  19. Why does autoReconnect=true not seem to work?
  20. How does Class.forName() work?
  21. Tomcat vs Weblogic JNDI Lookup
  22. JDBC returning MySQLSyntaxError Exception with correct statement
  23. Can I create a custom classpath on a per application basis in Tomcat
  24. Adding jdbc driver to classpath
  25. com.mysql.jdbc.PacketTooBigException
  26. Whitelist security constraint in web.xml
  27. Oracle’s RETURNING INTO usage in Java (JDBC, Prepared Statement)
  28. Connection cannot be cast to oracle.jdbc.OracleConnection
  29. Iterating a ResultSet using the JDBC for Oracle takes a lot of time about 16s?
  30. How to use JTA support in Tomcat 6 for Hibernate?

Leave a Comment