用 jsp 编写了一个对于 mysql 数据库中的数据进行删除的代码，但报错，大神指点一下啊，3Q ！！！ - 编程论坛

registerform.jsp

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<html>
<head>
<title>表单</title>
</head>
<body>
<center>
<form action="registerform1.jsp" method="post">
<table align="center">
<tr>
   <td colspan="2">用户删除</td>
</tr>
<tr>
<td>用户名:</td>
<td><input type="text" name="username"/></td>
</tr>
<tr>
<td>用户ID:</td>
<td><input type="text" name="userid"/></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="删除"/> <input type="reset" value="重置"/></td>
</tr>
</table>
</form>
</center>
</body>
</html>

registerform1.jsp
<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<%@ page import="java.sql.*" %>
<html>
<head>
<title>数据库操作</title>
</head>
<body>
<%
request.setCharacterEncoding("gbk");
String userid1=request.getParameter("userid");
String username1=request.getParameter("username");
%>
<%
  Connection conn=null;
  PreparedStatement pre=null;
  String url="jdbc:mysql://localhost:3306/javaweb";
  String user="root";
  String password="504979454";
  try{
  Class.forName("com.mysql.jdbc.Driver");
  conn=DriverManager.getConnection(url,user,password);
  }catch(ClassNotFoundException e){
     out.println("加载JDBC失败");
  }catch(SQLException e){
     out.println("数据库加载失败");
  }%>
  <%try{
  String adduser="delete from customers where ID=? and NAME=?";
  pre=conn.prepareStatement(adduser);
  pre.setString(1,userid1);
  pre.setString(2,username1);
   int number=pre.executeUpdate();
      if(number==0){
      %>
   <jsp:forward page="registerform.jsp"/><%} %>
<%} %>
  <%catch(SQLException e){
  out.println("删除数据失败");
  e.printStackTrace();
  }
  try{
    if(pre!=null){
    pre.close();
    pre=null;
    }
    if(conn!=null){
    conn.close();
    conn=null;
    }
  }catch(SQLException e){
       out.println("数据库关闭失败");
  }
%>
</body>
</html>

执行结果：
HTTP Status 500 - org.apache.jasper.JasperException: Unable to load class for JSP

--------------------------------------------------------------------------------

type Exception report

message org.apache.jasper.JasperException: Unable to load class for JSP

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

exception

数据库：
ID      NAME    AGE
1    leili    24
2    leilxxi    22
3    james    21