tomcat7, hibernate 4, struts 2, No suitable driver found again

Question

I'm using hibernate 4.1.2 in a project based on struts framework 2.3.3 with tomcat 7.0.26. I'm also using mysql (and postgres) for my tests. This is my hibernate.cfg.xml with MySql:

<session-factory>

  <property name="c3p0.min_size">5</property>
  <property name="c3p0.max_size">20</property>
  <property name="c3p0.timeout">300</property>
  <property name="c3p0.max_statements">50</property>
  <property name="c3p0.idle_text_period">3000</property>

  <property name="show_sql">true</property>

  <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="connection.url">jdbc:mysql://localhost/struts2</property>
  <property name="connection.username">semperEst</property>
  <property name="connection.password">*******</property>
  <property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>

  <!-- Enable Hibernate's automatic session context management -->
  <property name="current_session_context_class">thread</property>

  <!-- Disable the second-level cache -->
  <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

  <!-- Drop and re-create the database schema on startup -->
  <property name="hbm2ddl.auto">create-drop</property>

  <mapping class="firstname.secondname.lesson2.User"/>

</session-factory>

My WEB-INF/lib contains:

antlr-2.7.7.jar

asm-3.3.jar

asm-commons-3.3.jar

asm-tree-3.3.jar

commons-fileupload-1.2.2.jar

commons-io-2.0.1.jar

commons-lang-2.4.jar

commons-lang3-3.1.jar

dom4j-1.6.1.jar

freemarker-2.3.19.jar

hibernate-commons-annotations-4.0.1.Final.jar 

hibernate-core-4.1.2.Final.jar

hibernate-jpa-2.0-api-1.0.1.Final.jar

javassist-3.11.0.GA.jar

javassist-3.15.0-GA.jar

jboss-logging-3.1.0.GA.jar

jboss-transaction-api_1.1_spec-1.0.0.Final.jar

log4j-1.2.16.jar

mysql-connector-java-5.1.20-bin.jar

ognl-3.0.5.jar

postgresql-9.1-902.jdbc4.jar

slf4j-api-1.6.4-sources.jar

slf4j-log4j12-1.6.4.jar

struts2-core-2.3.3.jar

xwork-core-2.3.3.jar

*I've already added mysql-connector-java-5.1.20-bin.jar in $CATALINA_HOME/lib*

but I still have this exception:

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/struts2 at java.sql.DriverManager.getConnection(DriverManager.java:604)

    at java.sql.DriverManager.getConnection(DriverManager.java:190)

    at  org.hibernate.service.jdbc.connections.internal.
       DriverManagerConnectionProviderImpl.
       getConnection(DriverManagerConnectionProviderImpl.java:192) 

    at org.hibernate.internal.
       AbstractSessionImpl$NonContextualJdbcConnectionAccess.
       obtainConnection(AbstractSessionImpl.java:278)

    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.
       obtainConnection(LogicalConnectionImpl.java:297)

    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.
       getConnection(LogicalConnectionImpl.java:169)

    at org.hibernate.engine.transaction.internal.
       jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67)

    at org.hibernate.engine.transaction.spi.
       AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)

    at org.hibernate.internal.SessionImpl.
       beginTransaction(SessionImpl.java:1363)

    at firstname.lastname.lesson2.
       PortfolioService.usernameExists(PortfolioService.java:122)

    at firstname.lastname.lesson2.CreateUser.validate(CreateUser.java:255)

    at com.opensymphony.xwork2.validator.ValidationInterceptor.
       doBeforeInvocation(ValidationInterceptor.java:251)

    at com.opensymphony.xwork2.validator.ValidationInterceptor.
       doIntercept(ValidationInterceptor.java:263)

    at org.apache.struts2.interceptor.validation.
       AnnotationValidationInterceptor.
       doIntercept(AnnotationValidationInterceptor.java:68)
at 
     .
     .
     .(struts activation frame...)
     .
     at org.apache.catalina.core.ApplicationFilterChain.
        internalDoFilter(ApplicationFilterChain.java:243)

     at org.apache.catalina.core.ApplicationFilterChain.
        doFilter(ApplicationFilterChain.java:210)

     at org.apache.catalina.core.StandardWrapperValve.
       invoke(StandardWrapperValve.java:224)

     at org.apache.catalina.core.StandardContextValve.
        invoke(StandardContextValve.java:169)

      at org.apache.catalina.authenticator.AuthenticatorBase.
        invoke(AuthenticatorBase.java:472)

      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)

      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)

      at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)

      at org.apache.catalina.core.StandardEngineValve.
         invoke(StandardEngineValve.java:118)

      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)

      at org.apache.coyote.http11.AbstractHttp11Processor.
          process(AbstractHttp11Processor.java:987)

      at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.
         process(AbstractProtocol.java:579)

      at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.
         run(JIoEndpoint.java:307)

      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)

      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)

      at java.lang.Thread.run(Thread.java:722)

With postgres, same problem. All works in a standalone application, without struts and tomcat.

Thanks in advance

Answer 1

The usual problem when this kind of thing happens ("No suitable driver found") is that your JDBC library is either in the wrong place (depends upon your requirements) or in too many places (such as in WEB-INF/lib as well as in the container's lib/ directory).

Which component is actually creating your JDBC connection pool? If it's Tomcat (which does not seem to be the case), then your mysql.jar needs to be in Tomcat's lib/ directory (and specifically NOT in your webapp's WEB-INF/lib). If you are doing everything within your webapp, then you probably want mysql.jar to be in WEB-INF/lib in your webapp and /not/ in Tomcat's lib directory.

If you have multiple webapps and some of them are using Tomcat's DataSource configuration, then it's best to put mysql.jar into Tomcat's lib/ directory and remove it from all webapps' WEB-INF/lib directories.