request.getParameter returns null in JSP
Form.jsp
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | <!DOCTYPE HTML PUBLIC"-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> Form <body bgcolor="#FFFFFF" text="#000000"> Please enter your details <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)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 | 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); } } } |
如标题所示，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。