我有一个使用.jsps和servlet的项目。我在两个文件之间转发请求时遇到困难：注册表单（jsp）和注册servlet。 servlet验证通过表单接收的数据，并处理用户创建。如果在注册期间发生任何错误，servlet还应通知.jsp。我试图使用JSTL标签来执行此操作，但在注册时，用户不会被重定向，也不会被servlet通知。
register.jsp
<%@ page language="java" session="true"contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Register</title>
<link href="style/style.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div class="container">
...
<div class="content">
<h2 class="form">Register</h2>
<form action="Register" method="post">
<p>
User name: <br /> <input type="text" name="username" /> <b> <c:out
value="${messages['userName']}" />
</b> <br /> First Name: <br /> <input type="text" name="fist_name" />
<b> <c:out value="${messages['firstName']}" />
</b> <br /> Last Name: <br /> <input type="text" name="last_name" />
<b> <c:out value="${messages['lastName']}" />
</b> <br /> Email Address: <br /> <input type="text" name="email" />
<b> <c:out value="${messages['email']}" />
</b> <br /> Password: <br /> <input type="password" name="password" />
<b> <c:out value="${messages['password']}" />
</b> <br /> Retype password: <br /> <input type="password"
name="password2" /> <b> <c:out
value="${messages['password2']}" />
</b> <br /> <b> <c:out value="${messages['password3']}" />
</b> <br /> <input type="submit" value="Register" />
</p>
</form>
<!-- end .content -->
</div>
<div class="footer">
<p align="center">© Books Point 2013</p>
<div align="center">
<!-- end .footer -->
</div>
</div>
<!-- end .container -->
</div>
</body>
</html>
servlet如下：
Register.java
import books.pointejb.User;
import books.pointejb.UserViewBean;
/**
* Servlet implementation class ValidateLoginServlet
*/
@WebServlet(description = "Validate Register Servlet", urlPatterns = {
"/Register", "/Register.do" })
public class Register extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final int MAX_LEN = 30;
private static final int MIN_LEN = 6;
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// get request parameters for username and password
String user = request.getParameter("username");
String firstName = request.getParameter("first_name");
String lastName = request.getParameter("last_name");
String email = request.getParameter("email");
String pwd = request.getParameter("password");
String pwd2 = request.getParameter("password2");
boolean ok = true;
// Validate parameters and forward them to the ejb
Map<String, String> messages = new HashMap<String, String>();
if (user != null) {
// Validate user name
if (user.trim().isEmpty()) {
messages.put("userName", "Please enter username");
ok = false;
} else if (!user.matches("^[a-zA-Z0-9]$")) {
messages.put("userName",
"Invalid username. The username should contain only aplhanumerical values");
ok = false;
} else if (user.length() > MAX_LEN) {
messages.put("userName",
"Invalid username. Username should not be more than "
+ MAX_LEN + " characters");
ok = false;
}
}
if (firstName != null) {
// Validate first name
if (firstName.trim().isEmpty()) {
messages.put("firstName", "Please enter your first name");
ok = false;
} else if (!firstName.matches("^[a-zA-Z]$")) {
messages.put("firstName",
"Invalid name. Use alpha values only.");
ok = false;
} else if (firstName.length() > MAX_LEN) {
messages.put("firstName",
"Invalid name. Name should be at most " + MAX_LEN
+ " characters long");
ok = false;
}
}
if (lastName != null) {
// Validate last name
if (lastName.trim().isEmpty()) {
messages.put("lastName", "Please enter your last name");
ok = false;
} else if (!lastName.matches("^[a-zA-Z]$")) {
messages.put("lastName", "Invalid name. Use alpha values only.");
ok = false;
} else if (lastName.length() > MAX_LEN) {
messages.put("lastName",
"Invalid name. Name should be at most " + MAX_LEN
+ " characters long");
ok = false;
}
}
if (email != null) {
// Email is specified as request parameter, do the business logic
// here.
if (email.trim().isEmpty()) {
messages.put("email", "Please enter email");
ok = false;
} else if (!email
.matches("([^.@]+)(\\.[^.@]+)*@([^.@]+\\.)+([^.@]+)")) {
messages.put("email", "Invalid email, please try again.");
ok = false;
}
}
if (pwd != null) {
// Validate password
if (pwd.trim().isEmpty()) {
messages.put("password", "Please enter password");
ok = false;
} else if (pwd.length() < MIN_LEN && pwd.length() > MAX_LEN) {
messages.put("password",
"Invalid password. It must have at least " + MIN_LEN
+ " characters, but not more than " + MAX_LEN);
ok = false;
}
if (pwd2 != null) {
// Validate password
if (pwd2.trim().isEmpty()) {
messages.put("password2", "Please enter password");
ok = false;
} else if (pwd2.length() < MIN_LEN && pwd2.length() > MAX_LEN) {
messages.put("password2",
"Invalid password. It must have at least "
+ MIN_LEN
+ " characters, but not more than "
+ MAX_LEN);
ok = false;
} else if (!pwd2.equals(pwd)) {
messages.put("password3", "Passwords do not match");
ok = false;
}
}
if (!ok) {
// Put messages in request scope so that it's accessible in EL
// by
// ${messages}.
request.setAttribute("messages", messages);
// Forward request to JSP for display.
request.getRequestDispatcher("/register.jsp").forward(request,
response);
} else {
// Send data to ejb
UserViewBean userBean = Lookup.doLookupUser();
User registerUser = new User();
// Set the username
registerUser.setUsername(user);
// Set the first name
registerUser.setFirstName(firstName);
// Set last name
registerUser.setLastName(lastName);
// Set email
registerUser.setEmail(email);
// Set the password(the bean computes the hash as well)
registerUser.setPassword(pwd);
// Now we try to register the new user. Additionally we log him in.
if (userBean.register(registerUser)) {
// Add a session variable based on the local date, remote
// address,
// remote port
// and username if the provided credentials(user/pass) are
// valid
String sessionData = now();
sessionData = sessionData + " " + request.getRemoteAddr();
sessionData = sessionData + " " + request.getRemotePort();
sessionData = sessionData + " " + user;
String generatedSession = null;
try {
// Create MessageDigest instance for MD5
MessageDigest md = MessageDigest.getInstance("SHA-512");
// Add password bytes to digest
md.update(sessionData.getBytes());
// Get the hash's bytes
byte[] bytes = md.digest();
// This bytes[] has bytes in decimal format;
// Convert it to hexadecimal format
StringBuilder sb = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
sb.append(Integer.toString(
(bytes[i] & 0xff) + 0x100, 16).substring(1));
}
// Get complete hashed password in hex format
generatedSession = sb.toString();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
// Get the request session and set new variables
request.getSession().setAttribute(cookieid,
generatedSession);
// Also store cookie in a safe place(the cookie jar)
CookieJar.userCookie = generatedSession;
// Send the request back with the session set
request.getRequestDispatcher("/register.jsp").forward(request,
response);
} else {
// Code to be executed if registration goes wrong
}
}
}
}
private static final String DATE_FORMAT_NOW = "yyyy-MM-dd HH:mm:ss";
private static final String cookieid = "CookieId";
...
}
虽然servlet设置属性并将它们转发给register.jsp，但页面在输入无效时不显示错误消息。
修改
import books.pointejb.User;
import books.pointejb.UserViewBean;
/**
* Servlet implementation class ValidateLoginServlet
*/
@WebServlet(description = "Validate Register Servlet", urlPatterns = {
"/Register", "/Register.do" })
public class Register extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final int MAX_LEN = 30;
private static final int MIN_LEN = 6;
private static final boolean DEBUG = true;
private static final String LOG = "books_point_log.txt";
private PrintWriter logThis = null;
private void InitLog() {
try {
logThis = new PrintWriter(LOG, "UTF-8");
} catch (FileNotFoundException e) {
System.out.println("[I] Exception " + e.toString() + " \n Stacktrace: ");
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
System.out.println("[I] Exception " + e.toString() + " \n Stacktrace: ");
e.printStackTrace();
}
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// get request parameters for username and password
String user = request.getParameter("username");
String firstName = request.getParameter("first_name");
String lastName = request.getParameter("last_name");
String email = request.getParameter("email");
String pwd = request.getParameter("password");
String pwd2 = request.getParameter("password2");
boolean ok = true;
// Validate parameters and forward them to the ejb
Map<String, String> messages = new HashMap<String, String>();
// Initialize output file
if(DEBUG) {
InitLog();
}
if (user != null) {
// Validate user name
if (user.trim().isEmpty()) {
messages.put("userName", "Please enter username");
if(DEBUG) {
logThis.println("userName Please enter username");
}
ok = false;
} else if (!user.matches("^[a-zA-Z0-9]$")) {
messages.put("userName",
"Invalid username. The username should contain only aplhanumerical values");
if(DEBUG) {
logThis.println("userName Invalid username. The username should contain only aplhanumerical values");
}
ok = false;
} else if (user.length() > MAX_LEN) {
messages.put("userName",
"Invalid username. Username should not be more than "
+ MAX_LEN + " characters");
if(DEBUG) {
logThis.println("userName Invalid username. Username should not be more than "
+ MAX_LEN + " characters");
}
ok = false;
}
} else {
ok = false;
}
if (firstName != null) {
// Validate first name
if (firstName.trim().isEmpty()) {
messages.put("firstName", "Please enter your first name");
if(DEBUG) {
logThis.println("firstName Please enter your first name");
}
ok = false;
} else if (!firstName.matches("^[a-zA-Z]$")) {
messages.put("firstName",
"Invalid name. Use alpha values only.");
if(DEBUG) {
logThis.println("firstName Invalid name. Use alpha values only.");
}
ok = false;
} else if (firstName.length() > MAX_LEN) {
messages.put("firstName",
"Invalid name. Name should be at most " + MAX_LEN
+ " characters long");
if(DEBUG) {
logThis.println("firstName Invalid name. Name should be at most " + MAX_LEN
+ " characters long");
}
ok = false;
}
} else {
ok = false;
}
if (lastName != null) {
// Validate last name
if (lastName.trim().isEmpty()) {
messages.put("lastName", "Please enter your last name");
if(DEBUG) {
logThis.println("lastName Please enter your last name");
}
ok = false;
} else if (!lastName.matches("^[a-zA-Z]$")) {
messages.put("lastName", "Invalid name. Use alpha values only.");
if(DEBUG) {
logThis.println("lastName Invalid name. Use alpha values only.");
}
ok = false;
} else if (lastName.length() > MAX_LEN) {
messages.put("lastName",
"Invalid name. Name should be at most " + MAX_LEN
+ " characters long");
if(DEBUG) {
logThis.println("lastName Invalid name. Name should be at most " + MAX_LEN
+ " characters long");
}
ok = false;
}
} else {
ok = false;
}
if (email != null) {
// Email is specified as request parameter, do the business logic
// here.
if (email.trim().isEmpty()) {
messages.put("email", "Please enter email");
if(DEBUG) {
logThis.println("email Please enter email");
}
ok = false;
} else if (!email
.matches("([^.@]+)(\\.[^.@]+)*@([^.@]+\\.)+([^.@]+)")) {
messages.put("email", "Invalid email, please try again.");
if(DEBUG) {
logThis.println("email Invalid email, please try again.");
}
ok = false;
}
} else {
ok = false;
}
if (pwd != null) {
// Validate password
if (pwd.trim().isEmpty()) {
messages.put("password", "Please enter password");
if(DEBUG) {
logThis.println("password Please enter password");
}
ok = false;
} else if (pwd.length() < MIN_LEN || pwd.length() > MAX_LEN) {
messages.put("password",
"Invalid password. It must have at least " + MIN_LEN
+ " characters, but not more than " + MAX_LEN);
if(DEBUG) {
logThis.println("password Invalid password. It must have at least " + MIN_LEN
+ " characters, but not more than " + MAX_LEN);
}
ok = false;
}
} else {
ok = false;
}
if (pwd2 != null) {
// Validate password
if (pwd2.trim().isEmpty()) {
messages.put("password2", "Please enter password");
if(DEBUG) {
logThis.println("password2 Please enter password2");
}
ok = false;
} else if (pwd2.length() < MIN_LEN || pwd2.length() > MAX_LEN) {
messages.put("password2",
"Invalid password. It must have at least " + MIN_LEN
+ " characters, but not more than " + MAX_LEN);
if(DEBUG) {
logThis.println("password2 Invalid password. It must have at least " + MIN_LEN
+ " characters, but not more than " + MAX_LEN);
}
ok = false;
} else if (!pwd2.equals(pwd)) {
messages.put("password3", "Passwords do not match");
if(DEBUG) {
logThis.println("password3 Passwords do not match");
}
ok = false;
}
} else {
ok = false;
}
if (!ok) {
// Put messages in request scope so that it's accessible in EL
// by
// ${messages}.
request.setAttribute("messages", messages);
// Forward request to JSP for display.
request.getRequestDispatcher("/register.jsp").forward(request,
response);
} else {
// Send data to ejb
UserViewBean userBean = Lookup.doLookupUser();
User registerUser = new User();
// Set the username
registerUser.setUsername(user);
// Set the first name
registerUser.setFirstName(firstName);
// Set last name
registerUser.setLastName(lastName);
// Set email
registerUser.setEmail(email);
// Set the password(the bean computes the hash as well)
registerUser.setPassword(pwd);
// Now we try to register the new user. Additionally we log him in.
if (userBean.register(registerUser)) {
// Add a session variable based on the local date, remote
// address,
// remote port
// and username if the provided credentials(user/pass) are
// valid
String sessionData = now();
sessionData = sessionData + " " + request.getRemoteAddr();
sessionData = sessionData + " " + request.getRemotePort();
sessionData = sessionData + " " + user;
String generatedSession = null;
try {
// Create MessageDigest instance for MD5
MessageDigest md = MessageDigest.getInstance("SHA-512");
// Add password bytes to digest
md.update(sessionData.getBytes());
// Get the hash's bytes
byte[] bytes = md.digest();
// This bytes[] has bytes in decimal format;
// Convert it to hexadecimal format
StringBuilder sb = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
sb.append(Integer.toString((bytes[i] & 0xff) + 0x100,
16).substring(1));
}
// Get complete hashed password in hex format
generatedSession = sb.toString();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
// Add log operation to log file
if(DEBUG) {
logThis.println("User " + registerUser.getUsername() + " successfully registered");
}
// Get the request session and set new variables
request.getSession().setAttribute(cookieid, generatedSession);
// Also store cookie in a safe place(the cookie jar)
CookieJar.userCookie = generatedSession;
// Send the request back with the session set
request.getRequestDispatcher("/register.jsp").forward(request,
response);
} else {
// Code to be executed if registration goes wrong
if(DEBUG) {
logThis.println("Failed to register user " + registerUser.getUsername());
}
}
}
// close logfile
if(DEBUG) {
logThis.close();
}
}
答案 0 :(得分：1)
你的
if (!ok) {
似乎在
之内if (pwd != null) {
块。
所以它只会在pwd != null时执行。
答案 1 :(得分：0)
我注意到 getServletConfig 方法只是一个存根。删除/评论此方法
public ServletConfig getServletConfig() {
// TODO Auto-generated method stub
return null;
}
解决了这个问题。