Java JList не отвечает правильно после добавления нового элемента

Question

У меня проблема с JList, и мне нужна ваша помощь! Я застрял в течение дня.

• Это мой JList:

  DefaultListModel lm = new DefaultListModel<>(); 
  
  // add "a", "b", "c" to lm 
  ... 
  
  list = new JList(lm); 
  

• Мой первоначальный JList:

  |a| 
  |b| 
  |c| 
  

• Если пользователь дважды щелкает все детали, я буду создавать новый пункт "d" и добавьте его в JList и обновите дисплей JList

  list.addMouseListener(new MouseAdapter() { 
      public void mouseClicked(MouseEvent evt) { 
       if (evt.getClickCount() == 1) 
       { 
        lm.add(..., ...); 
        list = new JList(lm); 
       } 
  

• Теперь у меня есть свой обновленный JList:

  |a| 
  |b| 
  |c| 
  |d| 
  

• Проблема заключается в том: теперь, когда я дважды щелкните любой элемент а, Ь, с, или г, чтобы добавить новый элемент (например, , добавьте «e» в конец JList), ничего не происходит. Мой JList больше не отвечает.

  Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1 
  at java.util.ArrayList.elementData(Unknown Source) 
  at java.util.ArrayList.get(Unknown Source) 
  at mainprocess.Main$4.valueChanged(Main.java:376) 
  at javax.swing.JList.fireSelectionValueChanged(Unknown Source) 
  at javax.swing.JList$ListSelectionHandler.valueChanged(Unknown Source) 
  at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown Source) 
  at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown Source) 
  at javax.swing.DefaultListSelectionModel.setValueIsAdjusting(Unknown Source) 
  at javax.swing.JList.setValueIsAdjusting(Unknown Source) 
  at javax.swing.plaf.basic.BasicListUI$Handler.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.dispatchEventImpl(Unknown Source) 
  at java.awt.EventQueue.access$500(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.EventDispatchThread.pumpEvents(Unknown Source) 
  at java.awt.EventDispatchThread.run(Unknown Source) 
  Exception in thread "AWT-EventQueue-0"  java.lang.ArrayIndexOutOfBoundsException 
  Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException 
  Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException 
  Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException 
  

Может кто-нибудь помочь?

Answer 1

Вы не должны переназначать list с помощью new JList, просто удалите эту линию.

if (evt.getClickCount() == 1) 
    { 
     lm.add(..., ...); 
    }