源代码:(只复制了一部分)
String iden = (String) identityBox.getSelectedItem();
if( tool.getConnection(userName,password,iden)){
if("用户".equals(iden)) {
错误:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at UserEnter.EnterFrame.loginActionPerformed(EnterFrame.java:192)
at UserEnter.EnterFrame$3.actionPerformed(EnterFrame.java:87)
要怎么修改啊