birt报表错误，org.eclipse.birt.report.data.oda.jdbc.JDBCException:

警告: Failed to load JDBC driver class: com.mysql.jdbc.Driver
2010-6-3 14:40:39 org.eclipse.birt.data.engine.odaconsumer.ConnectionManager openConnection
严重: Cannot open connection.
org.eclipse.birt.report.data.oda.jdbc.JDBCException: Cannot load JDBC Driver class: com.mysql.jdbc.Driver.
at org.eclipse.birt.report.data.oda.jdbc.JDBCDriverManager.findDriver(JDBCDriverManager.java:682)
at org.eclipse.birt.report.data.oda.jdbc.JDBCDriverManager.loadAndRegisterDriver(JDBCDriverManager.java:790)
at org.eclipse.birt.report.data.oda.jdbc.JDBCDriverManager.doConnect(JDBCDriverManager.java:202)
at org.eclipse.birt.report.data.oda.jdbc.JDBCDriverManager.getConnection(JDBCDriverManager.java:168)
at org.eclipse.birt.report.data.oda.jdbc.Connection.connectByUrl(Connection.java:166)
at org.eclipse.birt.report.data.oda.jdbc.Connection.open(Connection.java:123)
at org.eclipse.datatools.connectivity.oda.consumer.helper.OdaConnection.open(OdaConnection.java:235)
at org.eclipse.birt.data.engine.odaconsumer.ConnectionManager.openConnection(ConnectionManager.java:157)
at org.eclipse.birt.data.engine.executor.DataSource.newConnection(DataSource.java:210)
at org.eclipse.birt.data.engine.executor.DataSource.open(DataSource.java:197)
at org.eclipse.birt.data.engine.impl.DataSourceRuntime.openOdiDataSource(DataSourceRuntime.java:214)
at org.eclipse.birt.data.engine.impl.QueryExecutor.openDataSource(QueryExecutor.java:280)
at org.eclipse.birt.data.engine.impl.QueryExecutor.prepareExecution(QueryExecutor.java:224)
at org.eclipse.birt.data.engine.impl.PreparedQuery.doPrepare(PreparedQuery.java:508)
at org.eclipse.birt.data.engine.impl.PreparedDataSourceQuery.produceQueryResults(PreparedDataSourceQuery.java:189)
at org.eclipse.birt.data.engine.impl.PreparedDataSourceQuery.execute(PreparedDataSourceQuery.java:177)
at org.eclipse.birt.data.engine.impl.PreparedOdaDSQuery.execute(PreparedOdaDSQuery.java:143)
at org.eclipse.birt.report.data.adapter.impl.DataRequestSessionImpl.execute(DataRequestSessionImpl.java:470)
at org.eclipse.birt.report.engine.data.dte.DteDataEngine.doExecuteQuery(DteDataEngine.java:114)
at org.eclipse.birt.report.engine.data.dte.DataGenerationEngine.doExecuteQuery(DataGenerationEngine.java:79)
at org.eclipse.birt.report.engine.data.dte.AbstractDataEngine.execute(AbstractDataEngine.java:248)
at org.eclipse.birt.report.engine.executor.ExecutionContext.executeQuery(ExecutionContext.java:1676)
at org.eclipse.birt.report.engine.executor.QueryItemExecutor.executeQuery(QueryItemExecutor.java:77)
at org.eclipse.birt.report.engine.executor.TableItemExecutor.execute(TableItemExecutor.java:62)
at org.eclipse.birt.report.engine.internal.executor.wrap.WrappedReportItemExecutor.execute(WrappedReportItemExecutor.java:45)
at org.eclipse.birt.report.engine.internal.executor.emitter.ReportItemEmitterExecutor.execute(ReportItemEmitterExecutor.java:45)
at org.eclipse.birt.report.engine.internal.executor.dup.SuppressDuplicateItemExecutor.execute(SuppressDuplicateItemExecutor.java:42)
at org.eclipse.birt.report.engine.layout.html.HTMLBlockStackingLM.layoutNodes(HTMLBlockStackingLM.java:63)
at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layout(HTMLPageLM.java:90)
at org.eclipse.birt.report.engine.layout.html.HTMLReportLayoutEngine.layout(HTMLReportLayoutEngine.java:101)
at org.eclipse.birt.report.engine.presentation.ReportDocumentBuilder.build(ReportDocumentBuilder.java:195)
at org.eclipse.birt.report.engine.api.impl.RunTask.doRun(RunTask.java:228)
at org.eclipse.birt.report.engine.api.impl.RunTask.run(RunTask.java:89)
at org.eclipse.birt.report.service.ReportEngineService.runReport(ReportEngineService.java:1117)
at org.eclipse.birt.report.service.BirtViewerReportService.runReport(BirtViewerReportService.java:146)
at org.eclipse.birt.report.service.actionhandler.BirtRunReportActionHandler.__execute(BirtRunReportActionHandler.java:78)
at org.eclipse.birt.report.service.actionhandler.BirtGetPageActionHandler.__checkDocumentExists(BirtGetPageActionHandler.java:58)
at org.eclipse.birt.report.service.actionhandler.AbstractGetPageActionHandler.prepareParameters(AbstractGetPageActionHandler.java:119)
at org.eclipse.birt.report.service.actionhandler.AbstractGetPageActionHandler.__execute(AbstractGetPageActionHandler.java:104)
at org.eclipse.birt.report.service.actionhandler.AbstractBaseActionHandler.execute(AbstractBaseActionHandler.java:89)
at org.eclipse.birt.report.soapengine.processor.AbstractBaseDocumentProcessor.__executeAction(AbstractBaseDocumentProcessor.java:47)
at org.eclipse.birt.report.soapengine.processor.AbstractBaseComponentProcessor.executeAction(AbstractBaseComponentProcessor.java:159)
at org.eclipse.birt.report.soapengine.processor.BirtDocumentProcessor.handleGetPage(BirtDocumentProcessor.java:87)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.birt.report.soapengine.processor.AbstractBaseComponentProcessor.process(AbstractBaseComponentProcessor.java:111)
at org.eclipse.birt.report.soapengine.endpoint.BirtSoapBindingImpl.getUpdatedObjects(BirtSoapBindingImpl.java:66)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.axis.providers.java.RPCProvider.invokeMethod(RPCProvider.java:397)
at org.apache.axis.providers.java.RPCProvider.processMessage(RPCProvider.java:186)
at org.apache.axis.providers.java.JavaProvider.invoke(JavaProvider.java:323)
at org.apache.axis.strategies.InvocationStrategy.visit(InvocationStrategy.java:32)
at org.apache.axis.SimpleChain.doVisiting(SimpleChain.java:118)
at org.apache.axis.SimpleChain.invoke(SimpleChain.java:83)
at org.apache.axis.handlers.soap.SOAPService.invoke(SOAPService.java:454)
at org.apache.axis.server.AxisServer.invoke(AxisServer.java:281)
at org.apache.axis.transport.http.AxisServlet.doPost(AxisServlet.java:699)
at org.eclipse.birt.report.servlet.BirtSoapMessageDispatcherServlet.doPost(BirtSoapMessageDispatcherServlet.java:225)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:327)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.eclipse.birt.report.servlet.BirtSoapMessageDispatcherServlet.service(BirtSoapMessageDispatcherServlet.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.eclipse.birt.report.filter.ViewerFilter.doFilter(ViewerFilter.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
特别声明：不是mysql的驱动找不到，因为我在自己程序里写了一个demo，测试数据库的，测试成功，所以肯定不是mysql的驱动有问题，希望高手帮忙解决，谢谢！！！