Java Server Pages (JSP) - J2EE, Web-. JSP Web- , .
, , Java-, HTTP-, HTTP- , HTML. , , / , .
:
- , ;
- , ;
- , ;
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- .
, . javax.servlet.Filter, :
- void init (FilterConfig config) throws ServletException;
- void destroy();
- void doFilter (ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException;
init , , . doFilter . , init , , doFilter , . , , destroy.
package common;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class FilterConnect implements Filter{
private FilterConfig config = null;
private boolean active = false;
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
public void init (FilterConfig config) throws ServletException{
this.config = config;
String act = config.getInitParameter("active");
if (act!= null)
active = (act.toUpperCase().equals("TRUE"));
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
public void doFilter (ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException{
if (active){
//
@WebFilter @WebInitParam. web.xml:
<filter>
<filter-name>encodingfilter</filter-name>
<filter-class>by.bsu.sample.filter.EncodingFilter</filter-class>
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<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingfilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
- . : cookies .
Cookie - , . , cookie - - , . HTTP , . , . cookie , , getCookies() HttpServletRequest:
Cookie cookies[] = request.getCookies();
cookie getName() getValue().
cookie :
Cookie theCookie = new Cookie( cookie, cookie);
response.setContentType = "test/html";
response.addCookie(theCookie);
. , HttpServlet , HTTP. - HTTP , . . , , , getSession():
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletRequest {
HttpSession session = request.getSession(true);
...
, , . cookie, - . , cookie - (String), (Object). , , putValue getValue. :
private static final String SUM_KEY = "sum";
Integer count = 100;
session.putValue (SUM_KEY, count);
...
Integer sum = (Integer) session.getAttribute (SUM_KEY);
, HttpSession, Serializable. - , web . setAttribute() getAttribute(). , valueBound() valueUnbound().
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, HTTP . , , - .
-, .
1. BSAC. web.xml.
2. SessionFilter.
3. . .
<filter>
<filter-name>SessionFilter</filter-name>
<filter-class>by.bsac.session.SessionFilter</filter-class>
<init-param>
<param-name>ignore- urls </param-name>
<param-value>/BSAC/login,/BSAC/LoginController,/BSAC/error-login.jsp</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>SessionFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
: filter-name - ;
filter-class - , ;
init-param , ;
param-value ;
filter-mapping urla ;
url-pattern urla.
.. /* ( url).
web.xml :
<?xml version= "1.0" encoding= "UTF-8"?>
<web-app xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance" xmlns= "http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation= "http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version= "3.1" >
<display-name>BSAC</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>SessionFilter</filter-name>
<filter-class>by.bsac.session.SessionFilter</filter-class>
<init-param>
<param-name>ignore- urls </param-name>
<param-value>/BSAC/login,/BSAC/LoginController,/BSAC/error-login.jsp</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>SessionFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<description></description>
<display-name>LoginController</display-name>
<servlet-name>LoginController</servlet-name>
<servlet-class>by.bsac.profile.LoginController</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginController</servlet-name>
<url-pattern>/login</url-pattern>
<url-pattern>/logout</url-pattern>
</servlet-mapping>
</web-app>
4. :
package by.bsac.session;
import java.io.IOException;
import java.util.ArrayList;
import java.util.StringTokenizer;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
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import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import by.bsac.profile.ProfileTools;
public class SessionFilter implements Filter {
private ArrayList<String> ignoredUrlList;
/**
* @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
// uri
String requestUri = req.getRequestURI();
boolean shouldBeIgnored = isIgnoredUrl(requestUri);
// " url, ?"
// url ,
// login.jsp
if (!shouldBeIgnored &&!ProfileTools.isLoggedIn(req)) {
res.sendRedirect(req.getContextPath() + "/login.jsp");
} else {
// pass the request along the filter chain
chain.doFilter(request, response); //
}
}
/**
*
* @see Filter#init(FilterConfig)
*/
public void init(FilterConfig fConfig) throws ServletException {
// web.xml ignore-urls
ignoredUrlList = new ArrayList<String>();
// fConfig , init-param
String urls = fConfig.getInitParameter("ignore-urls");
// urlList
StringTokenizer token = new StringTokenizer(urls, ",");
while (token.hasMoreTokens()) {
ignoredUrlList.add(token.nextToken());
}
}
/**
* url url
* @param url - url
*/
private boolean isIgnoredUrl(String url) {
for (String ignoredUrl: getIgnoredUrlList()) {
if (url.startsWith(ignoredUrl)) {
return true;
}
}
return false;
}
public ArrayList<String> getIgnoredUrlList() {
return ignoredUrlList;
}
public void setIgnoredUrlList(ArrayList<String> urlList) {
this.ignoredUrlList = urlList;
}
@Override
public void destroy() {
// TODO Auto-generated method stub
}
}
5. ProfileTools:
package by.bsac.profile;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
public class ProfileTools {
public static String SESSION_LOGGEDIN_ATTRIBUTE_NAME = "user";
/* true ,
* . - false*/
public static boolean isLoggedIn(HttpServletRequest request) {
HttpSession session = request.getSession(false);
return session!= null && session.getAttribute(SESSION_LOGGEDIN_ATTRIBUTE_NAME)!= null;
}
}
6. login.jsp
1. <%@ page language= "java" contentType= "text/html; charset=UTF-8"
2. pageEncoding= "UTF-8" %>
3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4. <html>
5. <head>
6. <meta http-equiv= "Content-Type" content= "text/html; charset=UTF-8" >
7. <title>Login</title>
8. </head>
9. <body>
10. <form action= "login" method= "post" >
11. <input type= "hidden" name= "authAction" value= "login" >
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12. <p>Please login by
13. <label for= "email" >Email</label>
14. <input type= "radio" name= "authType" value= "email" id= "email" checked/>
15. or
16. <label for= "userName" >User name</label>
17. <input type= "radio" name= "authType" value= "userName" id= "userName" />
18. <input type= "text" name= "loginValue" >
19. </p>
20. <label for= "psw" >Password</label>
21. <input type= "password" name= "psw" id= "psw" >
22. <p>The characters in a password field are masked (shown as asterisks or circles).</p>
23.
24. <input type= "submit" value= "Submit" />
25. </form>
26. </body>
27. </html>
7. LoginController
package by.bsac.profile;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
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;
/**
* Servlet implementation class LoginController
*/
public class LoginController extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public LoginController() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.sendRedirect("login.jsp");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String authAction = request.getParameter("authAction");
if (authAction.equals("login")){
login(request, response);
} else if (authAction.equals("logout")){
logout(request, response);
} else {
}
}
private void logout(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session = request.getSession(false);
if (session!=null) {
session.invalidate();
}
response.sendRedirect("login.jsp");
}
private void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String authTypeParam = request.getParameter("authType");
Authenticator authenticator = new AuthenticatorImpl();
boolean isAuthentificated = false;
String password = request.getParameter("psw");
String authValue = request.getParameter("loginValue");
if (authTypeParam.equals("email")) {
isAuthentificated = authenticator.authenticateByUserEmail(authValue, password);
} else {
isAuthentificated = authenticator.authenticateByUserName(authValue, password);
}
if (isAuthentificated) {
HttpSession session=request.getSession();
session.setAttribute(ProfileTools.SESSION_LOGGEDIN_ATTRIBUTE_NAME, authValue);
response.sendRedirect("home.jsp");
}
else{
response.sendRedirect("error-login.jsp");
}
}
}
8. Authenticator:
package by.bsac.profile;
public interface Authenticator {
public boolean authenticateByUserName(String username, String password);
public boolean authenticateByUserEmail(String email, String password);
}
9. AuthenticatorImpl, :
package by.bsac.profile;
public class AuthenticatorImpl implements Authenticator {
private String username = "user";
private String password = "password";
private String email = "[email protected]";
@Override
public boolean authenticateByUserName(String username, String password) {
if ((getUsername().equalsIgnoreCase(username))
&& (getPassword().equals(password))) {
return true;
} else {
return false;
}
}
@Override
public boolean authenticateByUserEmail(String email, String password) {
if ((getEmail().equalsIgnoreCase(email))
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&& (getPassword().equals(password))) {
return true;
} else {
return false;
}
}
public String getPassword() {
return password;
}
public String getUsername() {
return username;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this. email = email;
}
}
10. error-login.jsp
<%@ page language= "java" contentType= "text/html; charset=UTF-8"
pageEncoding= "UTF-8" %>
<!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=UTF-8" >
<title>Login failed</title>
</head>
<body>
Login failed, please <a href= "/BSAC/login.jsp" >try again</a>.
</body>
</html>
11. home.jsp
<%@ page language= "java" contentType= "text/html; charset=UTF-8"
pageEncoding= "UTF-8" %>
<!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=UTF-8" >
<title>Home</title>
</head>
<body>
<h1>
Hello, <%= session.getAttribute("user") %>
</h1>
<form action= "logout" method= "post" >
<input type= "hidden" name= "authAction" value= "logout" >
<input type= "submit" value= "Logout" />
</form></body>
</html>
12. url. login.jsp. / email , home.jsp.
:
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2. . , HTML-, cookie, .
3. , , . ? cookie.
4. cookie , .
5. . cookie, .
6. . cookie, . : , .
7. , , , , . cookie , . : .
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