Pentaho data intégration

Bonjour,
j'utilise pdi pour me connecter sur ma datawarehouse qui est une base mysql, mais j'arrive pas à me connecter et il m'affiche le message d'erreur suivant:

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

Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Accès refusé pour l'utilisateur: ''@'@localhost' (mot de passe: NON)


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

Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Accès refusé pour l'utilisateur: ''@'@localhost' (mot de passe: NON)


at org.pentaho.di.core.database.Database.normalConnect(Database.java:312)
at org.pentaho.di.core.database.Database.connect(Database.java:261)
at org.pentaho.di.core.database.Database.connect(Database.java:223)
at org.pentaho.di.core.database.Database.connect(Database.java:213)
at org.pentaho.di.core.database.DatabaseFactory.getConnectionTestReport(DatabaseFactory.java:54)
at org.pentaho.di.core.database.DatabaseMeta.testConnection(DatabaseMeta.java:2409)
at org.pentaho.ui.database.event.DataHandler.testDatabaseConnection(DataHandler.java:487)
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:294)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:124)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:112)
at org.pentaho.ui.xul.swt.tags.SwtButton.access$000(SwtButton.java:17)
at org.pentaho.ui.xul.swt.tags.SwtButton$1.widgetSelected(SwtButton.java:77)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:820)
at org.eclipse.jface.window.Window.open(Window.java:796)
at org.pentaho.ui.xul.swt.tags.SwtDialog.show(SwtDialog.java:222)
at org.pentaho.di.ui.core.database.dialog.XulDatabaseDialog.open(XulDatabaseDialog.java:161)
at org.pentaho.di.ui.spoon.delegates.SpoonDBDelegate.editConnection(SpoonDBDelegate.java:79)
at org.pentaho.di.ui.spoon.Spoon.doubleClickedInTree(Spoon.java:2314)
at org.pentaho.di.ui.spoon.Spoon.access$1500(Spoon.java:240)
at org.pentaho.di.ui.spoon.Spoon$25.widgetDefaultSelected(Spoon.java:4006)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.pentaho.di.ui.spoon.Spoon.readAndDispatch(Spoon.java:940)
at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:5495)
at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:407)
Caused by: org.pentaho.di.core.exception.KettleDatabaseException:
Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Accès refusé pour l'utilisateur: ''@'@localhost' (mot de passe: NON)

at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:435)
at org.pentaho.di.core.database.Database.normalConnect(Database.java:296)
... 36 more
Caused by: java.sql.SQLException: Accès refusé pour l'utilisateur: ''@'@localhost' (mot de passe: NON)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2975)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:798)
at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3700)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1203)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2572)
at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:421)
... 37 more

!DatabaseMeta.report.Hostname!
!DatabaseMeta.report.Port!3306
!DatabaseMeta.report.DatabaseName!datawarehouse

est ce que quelqu'un peut m'aider!!!! c très urgent!!!!!!!
merciiii