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java - JSP解析时出错

转载 作者：行者123 更新时间：2023-11-29 07:58:25 30 4
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我正在尝试在 MySql 数据库中存储一些值。该值是从jsp页面获取的。但是解析似乎存在一些问题，我无法弄清楚。这是我的代码

JSP

<%@page import="register.register"%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>PenguinSoft(India)</title>
<meta name="keywords" content="" />
<meta name="description" content="" />
<link href="default.css" rel="stylesheet" type="text/css" />
</head>
<body>

        <%//**The Problem is Somewhere in this part of code**
                        String stdname = request.getParameter("student");
                        String batch = request.getParameter("batch");
                                                String email = request.getParameter("email");
                                                String contact = request.getParameter("contact");
                        String msg;
                                                String fees=request.getParameter("fees");
                        int stdcontact=Integer.parseInt(contact);
                                                int stdfees=Integer.parseInt(fees);
                        if (stdname!= null ) {
                            register objadd = new register();
                            boolean flag = objadd.InsertNew(stdname,batch,email,stdcontact,stdfees);
                            if (flag) {
                                request.getRequestDispatcher("success.jsp").forward(request, response);
                            } else {
                                msg = "Invalid data entered!";
                            }
                        }
                    %>
<form action="Register.jsp" method="POST">

<div id="header">
    <div id="logo">
        <h1><a href="#"></a></h1>
        <h3><a href="#">PenguinSoft</a></h3>
    </div>
    <div id="menu">
        <ul>
            <li class="first"><a href="#" title="">New Batch</a></li>
            <li><a href="Login.jsp" title="">Register Student</a></li>
            <li><a href="AddEmployeeData.jsp" title="">Fees Record</a></li>
            <li><a href="AddKeywords.jsp" title="">Manage Student</a></li>
            <li><a href="StopWordDetectionForm.jsp" title="">All Details</a></li>
        </ul>
    </div>
    <div id="ad468x60"><a href="#"><img src="images/spam1.gif" alt="" width="468" height="60" /></a></div>
</div>
<div id="page">
    <div id="content">
        <div class="boxed">
            <h1 class="heading">Welcome to SPAM Management</h1>
            <div class="content">
                <img src="images/no-spam-2x.gif" alt="" width="122" height="123" class="left" />
                <p></p>
                <p></p>



<blockquote>


<p align="left"><font size="3">Student Name&nbsp;
</font>
<input type="text" name="student" size="26" style="font-family: Tahoma; font-size: 10pt" onBlur="return one(this.form)"/></p>
<p align="left"><font size="3">Batch<select name="batch">
            <option>Java</option>
            <option>PHP</option>
            <option>Framework</option>
            <option>Android</option>
            </select>
</font>
</p>
<p align="left"><font size="3">Email ID&nbsp;
</font>
<input type="text" name="email" size="26" style="font-family: Tahoma; font-size: 10pt" onBlur="return one(this.form)"/></p>
<p align="left"><font size="3">Contact No.&nbsp;
</font>
<input type="text" name="contact" size="26" style="font-family: Tahoma; font-size: 10pt" onBlur="return one(this.form)"/></p>
 <p align="left"><font size="3">Fees&nbsp;
</font>
<input type="text" name="fees" size="26" style="font-family: Tahoma; font-size: 10pt" onBlur="return one(this.form)"/></p>   
<p align="left">
</p><br>
<input type="submit" value="Register Student"name="submit" align="center"/>
</form>
            </div>
        </div>
    </div>
    <!-- end #content -->
    <div id="sidebar">
        <div class="boxed">
            <h2 class="heading">Key Features: </h2>
            <div class="content">
                <ul>
                    <li>PenguinSoft(India) is one of the major leading training institute in Software Development in India.</li>
                    <li>Training provided in Java,PHP,Android,database,etc</li>
                    <li>Live project development is also provided</li>
                </ul>
            </div>
        </div>
    </div>
    <!-- end #sidebar -->
</div>
<!-- end #page -->
<div style="clear: both;">&nbsp;</div>
<div id="footer">
    <p id="legal">Copyright &copy; PenguinSoft(India) All Rights Reserved.</p>
    <p id="links"><a href="#">Privacy Policy</a> | <a href="#">Terms of Use</a></p>*/
</div>
</body>
</html>

Java 类

package register;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author asus
 */
public class register {


    public boolean InsertNew(String stdname,String stdbatch,String email,int contact,int fees){
          boolean flag = false;
          Connection con = null;
          String connectionURL = "jdbc:mysql://localhost:3306/penguinsoft";

        Connection connection = null;
        ResultSet rs;       

        try {
            // Load the database driver
            Class.forName("com.mysql.jdbc.Driver");
            // Get a Connection to the database
            connection = DriverManager.getConnection(connectionURL, "root", "");
            //Add the data into the database

            //String sql = "insert into sample values(?,?)";

            PreparedStatement pst = connection.prepareStatement("INSERT into alldetails VALUES(?,?,?,?,?,?)");

            pst.setString(1,null);
            pst.setString(2,stdname);
            pst.setString(3,email);
            pst.setInt(4,contact);
            pst.setString(5,stdbatch);
            pst.setInt(6,fees);


            int numRowsChanged = pst.executeUpdate();
            if(numRowsChanged!=0){
                System.err.println("Successfull execution");
            }
            else{
                            System.err.println("Problem with the insertion query");
            }
            pst.close();
            }
            catch(ClassNotFoundException e){
                            e.printStackTrace();
            }
            catch(SQLException e){
                            e.printStackTrace();
            }
            catch (Exception e){
                            e.printStackTrace();
            }
            finally {
            // Always close the database connection.
            try {
            if (connection != null) connection.close();
            }
            catch (SQLException ignored){
            }
            }

           return true;
         }


}

错误

HTTP Status 500 - An exception occurred processing JSP page /Register.jsp at line 21

type Exception report

message An exception occurred processing JSP page /Register.jsp at line 21

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

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /Register.jsp at line 21

18:                                                 String contact = request.getParameter("contact");
19:                         String msg;
20:                                                 String fees=request.getParameter("fees");
21:                         int stdcontact=Integer.parseInt(contact);
22:                                                 int stdfees=Integer.parseInt(fees);
23:                         if (stdname!= null ) {
24:                             register objadd = new register();


Stacktrace:
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)

root cause

java.lang.NumberFormatException: null
    java.lang.Integer.parseInt(Integer.java:454)
    java.lang.Integer.parseInt(Integer.java:527)
    org.apache.jsp.Register_jsp._jspService(Register_jsp.java:84)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.41 logs.

问题似乎出在 JSP 文件中...请帮我解决

最佳答案

堆栈跟踪清楚地告诉异常

NumberFormatException

在行

int stdcontact=Integer.parseInt(contact);

其中联系人为null

parseInt()

抛出:

NumberFormatException - if the string does not contain a parsable integer.

在您的情况下，它是 null ，不可解析。

用 try/catch 包围您的代码，并添加 null 检查。

关于java - JSP解析时出错，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24512166/

30 4 0
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