Bonjour;

j'essaye de créer une extension java sur GVsig en se basant sur le tutorial suivant :
mais lors de l'exécution Gvsig m'affiche le message suivant :
Erreur non capturée par l'utilisateur
java.lang.NullPointerException: null
com.iver.andami.ui.mdiFrame.MDIFrame.actionPerform ed(MDIFrame.java:673) javax.swing.AbstractButton.fireActionPerformed(Unk nown Source) javax.swing.AbstractButton$Handler.actionPerformed (Unknown Source) javax.swing.DefaultButtonModel.fireActionPerformed (Unknown Source)
javax.swing.DefaultButtonModel.setPressed(Unknown Source)
javax.swing.AbstractButton.doClick(Unknown Source)
javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unk nown Source) javax.swing.plaf.basic.BasicMenuItemUI$Handler.mou seReleased(Unknown Source) java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
java.awt.Component.processMouseEvent(Unknown Source)
javax.swing.JComponent.processMouseEvent(Unknown Source)
java.awt.Component.processEvent(Unknown Source)
java.awt.Container.processEvent(Unknown Source)
java.awt.Component.dispatchEventImpl(Unknown Source)
java.awt.Container.dispatchEventImpl(Unknown Source)
java.awt.Component.dispatchEvent(Unknown Source)
java.awt.LightweightDispatcher.retargetMouseEvent( Unknown Source) java.awt.LightweightDispatcher.processMouseEvent(U nknown Source)
java.awt.LightweightDispatcher.dispatchEvent(Unkno wn Source)
java.awt.Container.dispatchEventImpl(Unknown Source)
java.awt.Component.dispatchEvent(Unknown Source)
java.awt.EventQueue.dispatchEvent(Unknown Source) com.iver.andami.ui.AndamiEventQueue.dispatchEvent( AndamiEventQueue.java:58) java.awt.EventDispatchThread.pumpOneEventForHierar chy(Unknown Source) java.awt.EventDispatchThread.pumpEventsForHierarch y(Unknown Source) java.awt.EventDispatchThread.pumpEvents(Unknown Source)
java.awt.EventDispatchThread.pumpEvents(Unknown Source)
java.awt.EventDispatchThread.run(Unknown Source)
je vous serais très reconnaissante pour votre aide