MySQL

[GiorgioG]

I\'m trying to use MySQL as a database backend while I teach myself the ins & outs of Websphere. At the moment I\'m deploying to Tomcat 4.0. Using the JDBC MySQL driver available from MySQL\'s web site I get a ClassNotFoundException error on this line of code:

Class.forName(\"org.gjt.mm.mysql.Driver\").newInstance();

in a java source file.

What\'s really weird is that the exact same code works in a .jsp page.

I\'ve added the .jar (and also tried unjar\'ing it) in all the lib folders, (tomcat\'s common/lib), websphere\'s own jre/lib & jdk/lib folder, etc. I\'m still getting the same problem and I have no idea why.

Code Snippet:

Class.forName(\"org.gjt.mm.mysql.Driver\").newInstance();
java.sql.Connection conn;
conn=java.sql.DriverManager.getConnection(\"jdbc:mysql://localhost/ContentHive?user=root&password=\");
java.sql.Statement Stmt = conn.createStatement();
java.sql.ResultSet RS = Stmt.executeQuery(\"SELECT * from menus\");

Does anyone have any idea why this is happening?

[billylo]

The short answer is to put your MySQL driver in your WAR file (under WEB-INF/lib).

The long answer: there are a few different ways to achieve this. WebSphere or other J2EE servers uses their own classloaders to achieve dynamic reload (updating code while the server is still up). For a WebSphere ClassLoader 101 discussion, see this article on WSDD.

http://www7b.boulder.ibm.com/wsdd/library/techarticles/0112_deboer/deboer.html