Error Connecting to database

Hi ,
I am a new Pentaho user. I am trying to connect to Oracle database and I am receiving this error message:
- I have already added the data source entry in my simple-jndi\defualtproperties file . and
-copied my database driver into \lib\jdbc driver in report designer folder.
Do you think there is a problem with the oracle db connection ?

Error connecting to database [XXX] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occured while trying to connect to the database


javax.naming.NamingException: Invalid data source:'XXX'
Invalid data source:'XXX'




org.pentaho.di.core.exception.KettleDatabaseException:
Error occured while trying to connect to the database


javax.naming.NamingException: Invalid data source:'XXX'
Invalid data source:'XXX'




at org.pentaho.di.core.database.Database.normalConnect(Database.java:366)
at org.pentaho.di.core.database.Database.connect(Database.java:315)
at org.pentaho.di.core.database.Database.connect(Database.java:277)
at org.pentaho.di.core.database.Database.connect(Database.java:267)
at org.pentaho.di.core.database.DatabaseFactory.getConnectionTestReport(DatabaseFactory.java:86)
at org.pentaho.di.core.database.DatabaseMeta.testConnection(DatabaseMeta.java:2464)
at org.pentaho.ui.database.event.DataHandler.testDatabaseConnection(DataHandler.java:533)
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.pentaho.ui.xul.impl.AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:329)
at org.pentaho.ui.xul.swing.tags.SwingButton$OnClickRunnable.run(SwingButton.java:58)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.Dialog$1.run(Unknown Source)
at java.awt.Dialog$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Dialog.show(Unknown Source)
at java.awt.Component.show(Unknown Source)
at java.awt.Component.setVisible(Unknown Source)
at java.awt.Window.setVisible(Unknown Source)
at java.awt.Dialog.setVisible(Unknown Source)
at org.pentaho.ui.xul.swing.tags.SwingDialog.show(SwingDialog.java:234)
at org.pentaho.reporting.ui.datasources.jdbc.ui.XulDatabaseDialog.open(XulDatabaseDialog.java:256)
at org.pentaho.reporting.ui.datasources.jdbc.ui.ConnectionPanel$EditDataSourceAction.actionPerformed(ConnectionPanel.java:159)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.Dialog$1.run(Unknown Source)
at java.awt.Dialog$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Dialog.show(Unknown Source)
at java.awt.Component.show(Unknown Source)
at java.awt.Component.setVisible(Unknown Source)
at java.awt.Window.setVisible(Unknown Source)
at java.awt.Dialog.setVisible(Unknown Source)
at org.pentaho.reporting.libraries.designtime.swing.CommonDialog.performEdit(CommonDialog.java:156)
at org.pentaho.reporting.ui.datasources.jdbc.ui.JdbcDataSourceDialog.performConfiguration(JdbcDataSourceDialog.java:759)
at org.pentaho.reporting.ui.datasources.jdbc.JdbcDataSourcePlugin.performEdit(JdbcDataSourcePlugin.java:67)
at org.pentaho.reporting.designer.core.actions.report.EditQueryAction.performEdit(EditQueryAction.java:150)
at org.pentaho.reporting.designer.core.editor.structuretree.StructureTreePanel$ReportTreeContextMenuHandler.mouseClicked(StructureTreePanel.java:140)
at java.awt.AWTEventMulticaster.mouseClicked(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.pentaho.di.core.database.DataSourceNamingException:
javax.naming.NamingException: Invalid data source:'XXX'
Invalid data source:'XXX'


at org.pentaho.di.core.database.util.DatabaseUtil.getNamedDataSource(DatabaseUtil.java:58)
at org.pentaho.di.core.database.Database.initWithNamedDataSource(Database.java:379)
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:405)
at org.pentaho.di.core.database.Database.normalConnect(Database.java:350)
... 86 more
Caused by: javax.naming.NamingException: Invalid data source:'XXX'
at org.pentaho.di.core.database.util.DatabaseUtil.getDataSourceFromJndi(DatabaseUtil.java:143)
at org.pentaho.di.core.database.util.DatabaseUtil.getNamedDataSource(DatabaseUtil.java:56)
... 89 more


JNDI Name : XXX