java开发中按右键popupMenu弹不出来,与JScrollPane有关

    private JPanel neighborPanel;
    private JList neighborList;
    private JPopupMenu neighborPanelPopupMenu;
    private JScrollPane  scrollPane;     neighborPanel=new JPanel();    
    neighborPanel.addMouseListener(new neighborPanelMouseListener());
    neighborPanelPopupMenu = new JPopupMenu();
    neighborPanelPopupMenu.add(new JMenuItem("好友"));
    neighborPanel.add(neighborPanelPopupMenu);
   scrollPane = new JScrollPane(new JScrollPane   (neighborList,JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));
    neighborPanel.add(scrollPane);//如果不写这句，就能产生MouseEvent,popup菜单就能弹出
    class neighborPanelMouseListener implements MouseListener{
       
         public void mouseClicked(MouseEvent e) {    
         }
         
         public void mouseEntered(MouseEvent e) {
          
         }
         public void mouseExited(MouseEvent e) {
          
         }
         public void mouseReleased(MouseEvent e) { 
          
         }
         public void mousePressed(MouseEvent e) { 
          
          System.out.println("mouse action");
          scrollPane.setOpaque(false);
          if (e.getButton() == 3) {            
         neighborPanelPopupMenu.show(neighborPanel, e.getX(), e.getY()); 
         }
             
         }
    
    
    
    }
以上是相关代码
我觉得jscrollpane的某些属性使鼠标事件无法产生