等待高人The server encountered an internal error () that prevented it from fulfilling this request.

The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /admin/login.jsp at line 28

25: try{
26: admin=new Admin(username);
27:
28: int M=admin.login(password,username);
29: out.println(M);
30: switch(M){
31: case 1:


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:398)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

root cause

javax.servlet.ServletException: java.lang.NoClassDefFoundError: hospital/db/DBConnection
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:850)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:779)
org.apache.jsp.admin.login_jsp._jspService(login_jsp.java:207)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

root cause

java.lang.NoClassDefFoundError: hospital/db/DBConnection
housemanager.db.dboperation.Admin.login(Admin.java:44)
org.apache.jsp.admin.login_jsp._jspService(login_jsp.java:113)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.16 logs.

<html>
<head>
<title></title>

</head>
<%
request.setCharacterEncoding("GBK");
String username="";
String password="";
String _login="";
Admin admin=(Admin)session.getAttribute("admin");

if(admin!=null)
_login="已登录";

if(request.getParameter("login")!=null){
username=request.getParameter("username");
password=request.getParameter("password");
//out.println(request.getParameter("login"));
try{
admin=new Admin(username);

int M=admin.login(password,username);
out.println(M);
switch(M){
case 1:
_login="登录成功";
session.setAttribute("admin",admin);
response.sendRedirect("main.jsp");
break;
case -2:
_login="密码错";
break;
case -1:
_login="数据库异常";
break;
case 0:
_login="一般异常";
break;
}
}
catch(InvalidUserException iue){
_login="非法用户名";
}
catch(Exception e){}
}
%>
<body bgcolor="#FFFFFF">
<table width="770" height="423" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#000000">
<tr>
<td height="421" bgcolor="#FFFFFF"><%@ include file = "../include/head.inc" %>
<table width="770" height="290" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<%@ include file="../include/admin.inc" %>
<td width="603" align="center" valign="top">
<table width="100%" height="85%" border="0" cellpadding="3" cellspacing="1" bgcolor="#666666">
<tr>
<td width="488" height="257" align="center" valign="top" bgcolor="E3EDFF">
<br>
<p><%=_login%></p>
<form method="POST" action="login.jsp?login=true">
<p>用户名：<input type="text" name="username"/></p>
<p>密码：<input type="password" name="password"/></p>
<p><input type="submit" value="登录"/>　<input type="reset" value="重填"/></p>
</form>
</td>
</tr>
</table>
</td>
</tr>
</table></td>
</tr>
</table>
</body>
</html>

这是我做提交的时候tomcat提示出现的错误，可是我上午都还能用，登陆都没有问题的，可是下午在登陆就出现这个问题了，请问高手是什么原因啊。是不是tomcat要重装啊，出现了内部错误