调用TreeSelectionListener接口后报错,请指点(在线等)
代码如下: 
 ------------------------------------- 
 import   java.awt.*; 
 import   java.awt.event.*; 
 import   javax.swing.*; 
 import   javax.swing.event.*; 
 import   javax.swing.tree.*;     
 public   class   EventFrame   extends   JFrame   implements   TreeSelectionListener{ 
       JPanel   contentPane; 
       JSplitPane   jSplitPane1   =   new   JSplitPane(); 
       JTree   jTree1   =   new   JTree(); 
 ……………… 
 _________________________________________________________________________ 
 现在报错如下: 
  "EventFrame.java ":   moneymanager.EventFrame   should   be   declared   abstract;   it   does   not   define   valueChanged(javax.swing.event.TreeSelectionEvent)   in   moneymanager.EventFrame   at   line   19,   column   1。   19行就是上面public   class……   那一行。请指点一下。谢谢
------解决方案--------------------你要实现valueChanged 
 这个方法。