Te adjunto el log del error
Cita: run:
Conexion establecida
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Acciones.AccionBotones.CargarRefrescoLimon(AccionB otones.java:37)
at Vistas_Botones.PanelBebidas.btnLimonActionPerforme d(PanelBebidas.java:315)
at Vistas_Botones.PanelBebidas.access$000(PanelBebida s.java:10)
at Vistas_Botones.PanelBebidas$1.actionPerformed(Pane lBebidas.java:68)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.jav a:6516)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3320)
at java.awt.Component.processEvent(Component.java:628 1)
at java.awt.Container.processEvent(Container.java:222 9)
at java.awt.Component.dispatchEventImpl(Component.jav a:4872)
at java.awt.Container.dispatchEventImpl(Container.jav a:2287)
at java.awt.Component.dispatchEvent(Component.java:46 98)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4422)
at java.awt.Container.dispatchEventImpl(Container.jav a:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719 )
at java.awt.Component.dispatchEvent(Component.java:46 98)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.j ava:735)
at java.awt.EventQueue.access$200(EventQueue.java:103 )
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPri vilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPri vilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPri vilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 705)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:91)
BUILD SUCCESSFUL (total time: 19 seconds)
Esta vez, el error empieza cuando le doy un valor al txtProductoId, linea 37 (panel.txtProducto.setText("401"); según entiendo en el log.