我试图通过在文本框中输入信息并单击提交按钮来将数据添加到sql数据库。但是，我无法让提交按钮正常工作。我对html并不熟悉，所以我可能做错了。这是一些代码。这是我的jsp页面，带有提交按钮。
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Student Page</title>
</head>
<body>
<table border="1" align="center">
<tr><td>Student ID</td><td>First Name</td><td>Last Name</td><td>Degree Program</td><td>Gender</td></tr>
<%
List<Student> students = (List) request.getAttribute("student");
for (Student student : students) { %>
<tr><td><%=student.getStudentId()%></td><td><%=student.getFirstname()%></td><td><%=student.getLastname()%></td><td><%=student.getDegreeprogram()%></td><td><%=student.getGender()%></td></tr>
<% }
%>
<tr><td> </td><td> </td><td><a href="/myweb">Go To Home Page</a></td><td> </td><td> </td></tr>
</table>
<form name="student" action="process" method="post">
<input type="hidden" name="view" value="addStudent" />
<table>
<tr><td> </td><td><Strong>Add a Student</Strong></td></tr>
<tr><td>Student ID: </td><td><input type="text" name="studentid" id="studentid"/></td></tr>
<tr><td>First Name: </td><td><input type="text" name="firstname" id="firstname"/></td></tr>
<tr><td>Last Name: </td><td><input type="text" name="lastname" id="lastname"/></td></tr>
<tr><td>Degree Program: </td><td><input type="text" name="degreeprogram" id="degreeprogram"/></td></tr>
<tr><td>Gender: </td><td><input type="text" name="gender" id="gender"/></td></tr>
<tr><td> </td><td><input type="submit"/></td></tr>
</table>
</form>
<form name="exit" action="process" method="post">
<input type="hidden" name="view" value="home" />
<p align="center"><input type="button" value="Exit"/></p>
</form>
</body>
</html>
这是我的servlet，其中进行查询以及将数据保存到数据库的位置。
@WebServlet(name="regservlet", urlPatterns={"/registrar"})
public class regservlet extends HttpServlet {
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
try {
String view = request.getParameter("view");
if (view != null) {
String jspName="/index.jsp";
HibernateUtil util = new HibernateUtil();
Session hibernateSession = (Session) util.getHibernateSession();
String tableName = "";
if (view.equalsIgnoreCase("Student")) {
tableName="Student";
Query q = hibernateSession.createQuery("from " + tableName);
List<Student> students = q.list();
jspName="/student.jsp";
request.setAttribute("student", students);
} else if (view.equalsIgnoreCase("Course")) {
tableName="Course";
Query q = hibernateSession.createQuery("from " + tableName);
List<Course> courses = q.list();
request.setAttribute("course", courses);
jspName="/course.jsp";
}
else if (view.equalsIgnoreCase("Enrollment")) {
tableName="Enrollment";
Query q = (Query) hibernateSession.createQuery("from " + tableName);
List<Enrollment> enrollment = q.list();
request.setAttribute("enrollment", enrollment);
jspName="/enrollment.jsp";
}
else if (view.equalsIgnoreCase("addStudent")) {
String studentid = request.getParameter("studentid");
String firstname = request.getParameter("firstname");
String lastname = request.getParameter("lastname");
String degreeprogram = request.getParameter("degreeprogram");
String gender = request.getParameter("gender");
Student myStudent = new Student(studentid, firstname, lastname, degreeprogram, gender);
hibernateSession.saveOrUpdate(myStudent);
Transaction t = hibernateSession.beginTransaction();
t.commit();
jspName="/index.jsp";
}
else if (view.equalsIgnoreCase("addCourse")) {
String courseid = request.getParameter("courseid");
String coursename = request.getParameter("course");
String coursesection = request.getParameter("coursesection");
String instructorId= request.getParameter("instructorid");
Course myCourse = new Course (courseid, coursename, coursesection, instructorId);
hibernateSession.saveOrUpdate(myCourse);
Transaction t = hibernateSession.beginTransaction();
t.commit();
jspName="/index.jsp";
}
else if (view.equalsIgnoreCase("addEnrollment")) {
String enrollmentid = request.getParameter("enrollmentid");
String course = request.getParameter("course");
String student = request.getParameter("student");
String semester= request.getParameter("semester");
Enrollment myEnrollment = new Enrollment(enrollmentid, course, student, semester);
hibernateSession.saveOrUpdate(myEnrollment);
Transaction t = hibernateSession.beginTransaction();
t.commit();
jspName="/index.jsp";
}
else if (view.equalsIgnoreCase("home")) {
jspName="/index.jsp";
}
hibernateSession.close();
System.out.println("JSP NAME "+jspName);
this.getServletContext().getRequestDispatcher(jspName).forward(request, response);
}
}catch (Exception ex) {
ex.printStackTrace();
System.err.println("Initial SessionFactory creation failed." + ex);
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
有什么建议吗？
答案 0 :(得分：2)
您的表单的操作设置为“处理”。您的servlet配置为作为“注册器”调用，因此永远不会被调用。
答案 1 :(得分：0)
HTML表单中的操作是“进程”。 servlet映射到URL“registrar” 这两个应该匹配。否则，应用程序服务器不知道将HTTP请求发送到何处。
首先搜索简单的Servlet教程。它需要15分钟才能阅读，成为servlet的世界级专家。祝你好运！