very thorough analysis hopefully quick question on location of mysql libraries
Tomcat managed database connections: Requires the MySQL connectors to be in $CATALINA_HOME/lib Hibernate managed database connections: Based on the above, you'll need to place the MySQL connection jar in your WEB-INF/lib directory. any reason why Tomcat managed DB connection would not read mysql jars located in WEB-INF/lib? thanks again Martin Gainty ______________________________________________ Verzicht und Vertraulichkeitanmerkung/Note de déni et de confidentialité Diese Nachricht ist vertraulich. Sollten Sie nicht der vorgesehene Empfaenger sein, so bitten wir hoeflich um eine Mitteilung. Jede unbefugte Weiterleitung oder Fertigung einer Kopie ist unzulaessig. Diese Nachricht dient lediglich dem Austausch von Informationen und entfaltet keine rechtliche Bindungswirkung. Aufgrund der leichten Manipulierbarkeit von E-Mails koennen wir keine Haftung fuer den Inhalt uebernehmen. Ce message est confidentiel et peut être privilégié. 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Étant donné que les email peuvent facilement être sujets à la manipulation, nous ne pouvons accepter aucune responsabilité pour le contenu fourni. > Date: Mon, 20 Jul 2009 19:56:32 -0700 > From: its_toas...@yahoo.com > Subject: Re: Seeking the right solution to java.lang.ClassNotFoundException: > com.mysql.jdbc.Driver > To: users@tomcat.apache.org > > > --- On Mon, 7/20/09, David Smith <d...@cornell.edu> wrote: > > > From: David Smith <d...@cornell.edu> > > Subject: Re: Seeking the right solution to > > java.lang.ClassNotFoundException: com.mysql.jdbc.Driver > > To: "Tomcat Users List" <users@tomcat.apache.org> > > Date: Monday, July 20, 2009, 6:16 PM > > Caldarale, Charles R wrote: > > >> From: David Smith [mailto:d...@cornell.edu] > > >> Subject: Re: Seeking the right solution to > > >> java.lang.ClassNotFoundException: > > com.mysql.jdbc.Driver > > >> > > >> This configuration is using a tomcat managed > > database pool. Put your > > >> mysql jar file in tomcat's lib folder and you'll > > see the error go away. > > >> > > > > > > But the stated intent is to use C3P0 pooling, rather > > than Tomcat's pooling; in that case, the <Resource> > > element must be removed and instead configured via whatever > > mechanism C3P0 wants. Can't have both. > > > > > > - Chuck > > > > > > > > > > > No argument here. I'm just diagnosing the current > > issue. If the OP > > wants help with C3PO, that should be the configuration we > > are given. > > > > --David > > Late to the thread, and this is probably overkill. > > This is my understanding concerning how the Tomcat / Hibernate / database > environment works. Your mileage may vary, and I will probably be corrected > by some people on the list. > > Please note that I've only used Tomcat managed database pooling. > > Tomcat Managed Database Pooling > =============================== > > Anyway, here is my environment. > > OS - Fedora 10 > =================== > jdk/jre - 1.6.0_14 > Tomcat - 6.0.20 > MySQL - 5.0.77-1 > IDE - NetBeans 6.7 > Hibernate - 3.2.5.ga (provided with NetBeans) > > OS - Windows/XP Professional SP 3 > =================== > jdk/jre - 1.6.0_14 > Tomcat - 6.0.20 > MySQL - 5.1.31 > IDE - NetBeans 6.7 > Hibernate - 3.2.5.ga (provided with NetBeans) > > I've chosen to use Tomcat's database pooling for the NetBeans DVD Store > tutorial sample application. This necessitates several changes in how the > application is configured. > > Basics > ====== > > 1. Per Tomcat documentation, I've placed > mysql-connector-java-5.0.8-bin.jar in Tomcat's lib directory. This > makes it available to Tomcat in order to set up database pooling > > 2. All Hibernate jars are located in WEB-INF/lib. NetBeans builds the > war file correctly, so I don't have to copy any jar files around. > > Web Application > =============== > > This also follows the Tomcat documentation for creating Tomcat-managed > connection pooling. > > 1. In META-INF/context.xml: > > <?xml version="1.0" encoding="UTF-8"?> > <Context antiJARLocking="true" path="/DVDStore"> > <Resource auth="Container" > driverClassName="com.mysql.jdbc.Driver" > maxActive="30" maxIdle="10" > maxWait="10000" name="jdbc/sakila" > password="*****" > type="javax.sql.DataSource" > url="jdbc:mysql://localhost/sakila" > username="*****"/> > </Context> > > Obviously, replace the asterisks with the appropriate username and > password. Replace the database url with your appropriate database. > > 2. In WEB-INF/web.xml: > > <resource-ref> > <description>This is a MySQL database connection</description> > <res-ref-name>jdbc/sakila</res-ref-name> > <res-type>javax.sql.DataSource</res-type> > <res-auth>Container</res-auth> > </resource-ref> > > Hibernate Configuration > ======================= > > So far, this has all been more or less boilerplate Tomcat > configuration. The next step is to get Hibernate to talk to Tomcat's > database connection pool as opposed to its own connection pool or a > direct connection. > > After searching a bit on the Internet, I found that the following > connection information works. > > 1. In hibernate.cfg.xml located in WEB-INF/: > > <!-- using container-managed JNDI --> > <propertyname="hibernate.connection.datasource"> > java:comp/env/jdbc/sakila > </property> > > Note that jdbc/sakila matches the web.xml resource-ref-name, which > matches the name attribute in context.xml. java:comp/env/ is the > namespace to look up the jdbc reference. > > No other connection or pooling information should be present in your > hibernate.cfg.xml file. > > Application Code > > ================ > > Since Hibernate hides a lot of the details for connection management, > this code should not have to change. In particular: > > 1. Creating the SessionFactory > > // SessionFactory from standard hibernate.cfg.xml file > > try { > sessionFactory = > new AnnotationConfiguration().configure().buildSessionFactory(); > } catch (Throwable ex) { > // Log the exception. > log.fatal("Initial SessionFactory creation failed.", ex); > throw new ExceptionInInitializerError(ex); > } > > 2. Getting the SessionFactory > > public static SessionFactory getSessionFactory() { > return sessionFactory; > } > > For my application, both of these code snippets live in > HibernateUtil.java. My code also creates an mbean for monitoring > Hibernate. > > You can then wrap this code up in a servlet context listener, which > should then create the session factory (which connects to the Tomcat - > provided connection pool) at application startup. It's also handy for > cleaning up resources when the application is shut down. In my case, > I use this to unregister the monitoring mbean. > > Other Notes > =========== > > If you look at your logs, you may see the following warning: > > INFO SessionFactoryObjectFactory:82 - > Not binding factory to JNDI, no JNDI name configured > > This is due to the fact that Hibernate can bind a session factory to a > JNDI name, but none is configured. This is not the JDBC resource. > This facility probably exists to make sharing session factories > easier, and to clean up calls like the following: > > Session session = HibernateUtil.getSessionFactory().openSession(); > > Tomcat provides a read-only InitialContext, while Hibernate requires > read-write. Tomcat is apparently following the specification for > unmanaged containers. If you want to bind the session factory to a > JNDI object, you'll either have to move to a managed server > (Glassfish, JBoss, etc.), or search on the Internet for some posted > work-arounds. > > The recommendation from the Hibernate documentation is to just leave > out the hibernate.session_factory_name property when working with > Tomcat to not try binding to JNDI. > > > Hibernate Managed Database Pooling > ================================== > > I've not tried this, since I always rely on container managed database > connections. However, after reading the documentation, I gather that > this is what needs to be done. > > Web Application Configuration > ============================= > > 1. Remove the <Resource></Resource> element from the context.xml > file. Tomcat is not going to be managing the database connection. > > 2. Remove the <resource-ref></resource-ref> element the web.xml file. > Tomcat is not going to be managing the database connection. > > Jar Files > ========= > > According to the Tomcat classloader documentation, Tomcat makes jar > files available to your application in the following order: > > * Bootstrap classes of your JVM > * System class loader classses (described above) > * /WEB-INF/classes of your web application > * /WEB-INF/lib/*.jar of your web application > * $CATALINA_HOME/lib > * $CATALINA_HOME/lib/*.jar > > In particular, the following two pieces of information should be > noted. > > 1. The jar files in lib/ are made available to both your application > and to Tomcat. Database connection jars are placed here if you > will be relying on Tomcat to manage connection pooling. > > 2. In general, application-specific jars (such as Hibernate's > connection pooling jars) should NOT be placed in the lib/ directory > of Tomcat. > > Based on the above, you'll need to place the MySQL connection jar in > your WEB-INF/lib directory. Hibernate ships with the CP30 connection > pooling classes, so as long as the Hibernate jars are in your > WEB-INF/lib directory (which they should be), you'll be fine. > > Hibernate Application Configuration > =================================== > > Since Hibernate will be managing both the connection and the database > pooling, you'll have to configure Hibernate with that information. > > In hibernate.cfg.xml, you'll need both connection information and > connection pooling information. Here are the snippets of that file > > <!-- connection information --> > <property name="hibernate.connection.driver_class"> > com.mysql.jdbc.Driver > </property> > <property name="hibernate.connection.url"> > jdbc:mysql://localhost/sakila > </property> > <property name="hibernate.connection.username">******</property> > <property name="hibernate.connection.password">******</property> > > <!-- database pooling information --> > <property name="connection_provider_class"> > org.hibernate.connection.CP30ConnectionProvider > </property> > <property name="c3p0.minPoolSize"> > 5 > </property> > <property name="c3p0.timeout"> > 1000 > </property> > > There are probably other properties to configure, but that should get > things up and running. As always, change the database properties to > reflect your particular application. > > Summary > ======= > > Tomcat managed database connections: > > 1. Requires META-INF/context.xml information > 2. Requires WEB-INF/web.xml information > 3. Requires a simple JNDI configuration referencing the connection > 4. Requires the MySQL connectors to be in $CATALINA_HOME/lib > 5. Requires the Hibernate jars to be in WEB-INF/lib > > Hibernate managed database connections: > > 1. Requires NO META-INF/context.xml information > 2. Requires NO WEB-INF/web.xml information > 3. Requires connection information to be in hibernate.cfg.xml > 4. Requires pooling information to be in hibernate.cfg.xml > 5. Requires MySQL connectors to be in WEB-INF/lib (ideally) > 6. Requires the Hibernate jars to be in WEB-INF/lib > > Hope this helps. > > /mde/ > > PS - I just hacked together the Hibernate-controlled database connection / > pooling on a freshly installed Tomcat 6.0.20. It works as advertised. > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > _________________________________________________________________ Windows Live™ Hotmail®: Celebrate the moment with your favorite sports pics. Check it out. http://www.windowslive.com/Online/Hotmail/Campaign/QuickAdd?ocid=TXT_TAGLM_WL_QA_HM_sports_photos_072009&cat=sports
