我想确保我能做到这一切。我从索引页开始。
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ page import="java.util.ArrayList" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Add a Customer/Pet</title>
</head>
<body>
<form method="get" action="customerServlet">
<a href="customerServlet?action=addCustomer">Add Customer</a>
<br/>
<a href="customerServlet?action=addPet">Add Pet</a>
</form>
</body>
</html>
在索引页面之后，如果该人选择添加宠物链接，它会将它们重定向到servlet，然后将它们带到pets.jsp页面，该页面工作正常。如果该人选择添加客户，则会将他们带到customerManagement.jsp页面，该页面应该使用 JSTL，我不知道如果我正确地做了
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ page import="java.util.ArrayList" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Customer Management</title>
</head>
<body>
<form action="customerServlet" method="post">
<c:set var="customer" scope="session" >
First Name:<br>
<input type="text" name="firstName" value="${customer.setFirstName() }"/><br>
Last Name:<br>
<input type="text" name="lastName" value="${customer.setLastName() }"/><br>
Email:<br>
<input type="text" name="email" value="${customer.setEmail() }"/><br>
Phone Number:<br>
<input type="text" name="phone" value="${customer.setPhone() }"/><br>
Phone Type:<br>
<select name="thePhones" id="selectPhones">
<option selected value="choose">
Select a Phone
</option>
<c:forEach items="${sessionScope.phones}" var="current" >
<option>${current.getPhoneName()}</option>
</c:forEach>
</select><br>
Street Address:<br>
<input type="text" name="streetAddress" value="${customer.setAddress() }"/><br>
City:<br>
<input type="text" name="city" value="${customer.setCity() }"/><br>
State:<br>
<select name="states" id="states">
<option selected value="Wisconsin">
Select a State
</option>
<c:forEach items="${sessionScope.states}" var="current" >
<option>${current.getStates()}</option>
</c:forEach>
</select>
<input type="submit" value="submit">
</c:set>
</form>
</body>
</html>
毕竟，这个人应该能够点击提交再次定向到servlet，
package edu.witc.Assignment03.controller;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//import javax.servlet.annotation.WebServlet;
//import javax.servlet.http.HttpServlet;
//import javax.servlet.http.HttpServletRequest;
//import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import edu.witc.Assignment03.model.Customer;
import edu.witc.Assignment03.model.Phone;
import edu.witc.Assignment03.model.States;
@WebServlet(description = "servlet to get act as controller between form and models", urlPatterns = { "/customerServlet","/addCustomer","/addPet", "/customerManagement" })
public class CustomerServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public CustomerServlet() {
super();
}
private List<edu.witc.Assignment03.model.Customer> customers = new ArrayList<Customer>();
private void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
HttpSession session = request.getSession();
Phone phone = new Phone();
States state = new States();
Collection<Phone> phones = phone.getPhoneCollection();
Collection<States> states = state.getStateCollection();
session.setAttribute("phones", phones);
session.setAttribute("states", states);
}
private void addCustomer(HttpServletResponse response, HttpServletRequest request)//redirect to form
throws IOException, ServletException {
String url = "/customerManagement.jsp";
processRequest(request, response);
request.getRequestDispatcher(url).forward(request,response);
}
private void addPet(HttpServletResponse response, HttpServletRequest request)//redirect to pet page
throws IOException, ServletException {
String url = "/pets.jsp";
request.getRequestDispatcher(url).forward(request,response);
}
private Customer getCustomer(int customerId) {
for (Customer customer : customers) {
if (customer.getCustomerId() == customerId) {
return customer;
}
}
return null;
}
private void makeCustomerReceipt(HttpServletRequest request,
HttpServletResponse response) throws IOException, ServletException {
String url = "/receipt.jsp";
request.setAttribute("customers", customers);
request.getRequestDispatcher(url).forward(request,response);
}
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
String action = request.getParameter("action");
if("addCustomer".equals(action)) {
addCustomer(response, request);
}
else if("addPet".equals(action)) {
addPet(response, request);
}
}
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
// update customer
int customerId = 0;
Customer testCustomer = new Customer();
testCustomer.setCustomerId(1);
testCustomer.setFirstName("Test");
customers.add(testCustomer);
try {
customerId =
Integer.parseInt(request.getParameter("id"));
} catch (NumberFormatException e) {
response.getWriter().write("Error: Customer ID could not be parsed to a number");
}
Customer customer = getCustomer(customerId);
if (customer != null) {
customer.setFirstName(request.getParameter("firstName"));
customer.setLastName(request.getParameter("lastName"));
customer.setEmail(request.getParameter("email"));
customer.setPhone(request.getParameter("phone"));
customer.setAddress(request.getParameter("address"));
customer.setCity(request.getParameter("city"));
customer.setZip(request.getParameter("zip"));
makeCustomerReceipt(request, response);
}
else
{
response.getWriter().write("Error: customer is null");
}
}
}
然后转到收据页面，向他们显示他们刚刚输入的信息。 （我认为这是你使用JARTL需要帮助的地方）
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%String firstName =request.getParameter("firstName"); %>
<%=firstName %>
</body>
</html>
我非常新，而且我已经走到了这一步。我想解释一下我做错了什么，并向我们展示如何纠正它。对不起，这个问题太长了，但我真的想弄明白我被卡住了。如果还需要添加其他内容，请告诉我们。