NullPointerException in Java Table Selecting rows
I am planning to have a table where there is a column that the user will be typing on (the user should enter a number) and everytime he types a number , it will be deducted on the column next to it, say: if I type 2, and the original number is 5, then the column should have 3. But I am having an error. So the first step i thought is to get the selected row.:
this is my FULL exception:
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.trackMouseEnterExit(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.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$200(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.security.P rotectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(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) Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1 at java.util.Vector.elementData(Unknown Source) at java.util.Vector.elementAt(Unknown Source) at javax.swing.table.DefaultTableModel.getValueAt(Unknown Source) at app.ui.Inventory.getSelectedQuanti ty(Inventory.java:363) at app.ui.Inventory$2.mouseEntered(Inventory.java:104) at java.awt.AWTEventMulticaster.mouseEntered(Unknown Source) at java.awt.AWTEventMulticaster.mouseEntered(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.trackMouseEnterExit(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(Un known Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$200(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(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.EventDispatch Thread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1 at java.util.Vector.elementData(Unknown Source) at java.util.Vector.elementAt(Unknown Source) at javax.swing.table.DefaultTableModel.getValueAt(Unknown Source) at app.ui.Inventory.getSelectedQuantity(Inventory.java:363) at app.ui.Inventory$2.mouseEntered(Inventory.java:104) at java.awt.AWTEventMulticaster.mouseEntered(Unknown Source) at java.awt.AWTEventMulticaster.mouseEntered(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.retargetMouseEven t(Unknown Source) at java.awt.LightweightDispatcher.trackMouseEnterExit(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.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$200(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivil ege(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) Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1 at java.util.Vector.elementData(Unknown Source)
MY TABLE IS NOT SORTED. IT IS JUST PLAIN. BUT I CHANGED THE ROW HEIGHT AND THE COLOR OF THE FONT.
This line:
java.lang.ArrayIndexOutOfBoundsException: -1 at java.util.Vector.elementData(Unknown Source)
Suggests there is no selected row when your getQuantity() method is called. Consequently tblInventory.getSelectedRow() will return -1 causing an ArrayOutOfBoundsException at this line:
String ballID = dtm.getValueAt(tblInventory.getSelectedRow(),0).toString();
Make sure there is a row selected when you do this call.
Of-topic
See these lines:
DefaultTableModel dtm = (DefaultTableModel) tblInventory.getModel();
String ballID = dtm.getValueAt(tblInventory.getSelectedRow(),0).toString();
Here tblInventory.getSelectedRow() is the selected row number in the view not the model . If your table is sorted then those indexes will be different causing an unexpected outcome. You have two options:
Request value to the table
//DefaultTableModel dtm = (DefaultTableModel) tblInventory.getModel();
String ballID = tblInventory.getValueAt(tblInventory.getSelectedRow(),0).toString();
Convert view index in its respective model index
int row = tblInventory.getSelectedRow();
int modelIndex = tblInventory.convertRowIndexToModel(row);
DefaultTableModel dtm = (DefaultTableModel) tblInventory.getModel();
String ballID = dtm.getValueAt(modelIndex,0).toString();
See: