在JSP中request.getParameter返回null [英] request.getParameter returns null in JSP
本文介绍了在JSP中request.getParameter返回null的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
Form.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Form</title>
<body bgcolor="#FFFFFF" text="#000000">
<h1>Please enter your details</h1>
<form name="RegistrationForm" action="NewUser" method="post">
<table cellspacing="5" cellpadding="5" border="1">
<tr>
<td align="right">First Name:</td>
<td><input type="text" name="NewFirstName"></td>
</tr>
<tr>
<td align="right">Last Name:</td>
<td><input type="text" name="NewLastName"></td>
</tr>
<tr>
<td align="right">Email Address:</td>
<td><input type="text" name="EmailAddress"></td>
</tr>
<tr>
<td align="right">Phone Number:</td>
<td><input type="text" name="Phone Number"></td>
</tr>
<tr>
<td align="right">Semester</td>
<td><input type="text" name="Semester"></td>
</tr>
</table>
<input type="submit" value="Submit">
</form>
</body>
</html>
NewUser.java(Servlet类)
NewUser.java(Servlet Class)
package com.seria.quiz;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class NewUser
*/
@WebServlet("/NewUser")
public class NewUser extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public NewUser() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter pw = response.getWriter();
Connection conn = null;
try {
String FirstName = request.getParameter("firstName");
System.out.println("Your firstname: " + FirstName);
String LastName = request.getParameter("lastName");
System.out.println("Your LastName: " + LastName);
String Emailid = request.getParameter("email");
String PhoneNumber = request.getParameter("phoneNumber");
String Semester = request.getParameter("semester");
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/seriaquiz", "root", "root");
PreparedStatement pst = (PreparedStatement) conn
.prepareStatement("insert into formdetails(firstName,lastName,email,phoneNumber,semester) values(?,?,?,?,?)");// try2
// the
// name
pst.setString(1, FirstName);
System.out.println("Your firstname1: " + FirstName);
pst.setString(2, LastName);
System.out.println("Your LastName1: " + LastName);
pst.setString(3, Emailid);
pst.setString(4, PhoneNumber);
pst.setString(5, Semester);
int i = pst.executeUpdate();
String msg = " ";
if (i != 0) {
msg = "Record has been inserted";
pw.println("<font size='6' color=blue>" + msg + "</font>");
} else {
msg = "failed to insert the data";
pw.println("<font size='6' color=blue>" + msg + "</font>");
}
pst.close();
} catch (Exception e) {
pw.println(e);
}
}
}
正如标题所述，request.getParameter每次都返回null.我将sysout语句放在requestParameter之后，它显示空值.任何帮助将不胜感激.抱歉给您带来不便，我是新来的.
As the title says request.getParameter is returning null every time. I put sysout statements after requestParameter, and it shows null value. Any help will be appreciated. Sorry for any inconvenience, I'm new here.
推荐答案
servlet中的参数名称需要在JSP中与之匹配
The parameter names in servlet need to match them in the JSP
如此
String FirstName = request.getParameter("firstName");
应该是
String FirstName = request.getParameter("NewFirstName");
这篇关于在JSP中request.getParameter返回null的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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