Question

我有一个简单的Web应用程序，可以在其中预订房间。如果我去预订的房间，我会列出我已预订的房间。现在，我想实现一个简单的按钮来删除特定的保留。在我的数据库中，我有：

hotel_booking

具有以下参数：

cid，cname，电子邮件，到达日期，离开日期，人，房间，type_room，评论，状态，uid。

现在我创建了：

cancel.jsp

这是代码：

<%@page contentType="text/html" pageEncoding="UTF-8"%>
 <%@ page import ="java.sql.*" %>
 <%
int id;
int person;
int room;



id = Integer.parseInt(request.getParameter("id"));
//  out.println(id);
String cname  = request.getParameter("cname");
 // out.println(cname);
String email  = request.getParameter("email");
String arrival  = request.getParameter("arrival_date");
String departure  = request.getParameter("departure_date");
person = Integer.parseInt(request.getParameter("person"));
room = Integer.parseInt(request.getParameter("room"));

  String type_room = request.getParameter("type_room");

Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/HotelReservation","root" ,"123456789");

String del = "delete from hotel_booking where id='" + Integer.parseInt(request.getParameter("id")) + "'AND cname='" + request.getParameter(cname) + "'AND emal='" + request.getParameter(email) + "'";

java.sql.Statement st = con.createStatement();

int rowNum = st.executeUpdate(del);
response.sendRedirect("home.jsp");
st.close();
%>

在booked.jsp中，我为取消按钮插入了此表单：

<form action='cancel.jsp'>
             <input type='submit' name='cancel' value='Cancel Reservation'>
             <input type="hidden" name="id" value=\""+id+"\">
            </form>
           </div>

但是我收到这种错误：

HTTP Status 500 – Internal Server Error

Type Exception Report

Message An exception occurred processing [/cancel.jsp] at line [10]

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.apache.jasper.JasperException: An exception occurred processing [/cancel.jsp] at line [10]

7: 
8: 
9: 
10: id = Integer.parseInt(request.getParameter("id"));
11: //  out.println(id);
12: String cname  = request.getParameter("cname");
13:  // out.println(cname);


Stacktrace:
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:593)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:482)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause

java.lang.NumberFormatException: For input string: "\""+id+"\""
    java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    java.lang.Integer.parseInt(Integer.java:580)
    java.lang.Integer.parseInt(Integer.java:615)
    org.apache.jsp.cancel_jsp._jspService(cancel_jsp.java:128)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:444)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Note The full stack trace of the root cause is available in the server logs.

我该如何解决？每当有人预订房间时，我的数据库中的cid参数就会自动增加一个。谢谢大家

Answer 1

尝试以下代码

<form action='cancel.jsp'>
 <input type="hidden" name="id" value="<%=id%>">
 <input type='submit' name='cancel' value='Cancel Reservation'>             
 </form>
</div>

因为id的值以“ \”“ + id +” \“”的形式传递。但是在您的代码中，您试图解析包含非数字值的字符串，因为Integer引发NumberFormatException。

取消对JAVA JSP的预订

1 个答案: