写一个这样的class
class myListCellRenderer extends DefaultListCellRenderer
 {       public myListCellRenderer() {
       
}
       public Component getListCellRendererComponent( JList list,
                  Object value,int index,
                  boolean isSelected,boolean cellHasFocus ) {              super.getListCellRendererComponent(list,value,index,isSelected,cellHasFocus);              setText( value.toString() );
              setToolTipText(value.toString());
              setOpaque( true );              return this;
       }
}然后myListCellRenderer mycell=new myListCellRenderer();
   
    list.setCellRenderer(mycell);