package cn.itcast.login;
public class User{
private String username;
private String password;
public User() {
super();
// TODO Auto-generated constructor stub
}
public User(String username, String password) {
super();
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}package cn.itcast.login;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//处理登陆请求
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//request.getAttribute("username"); //从域中取username
String username = request.getParameter("username");
String password = request.getParameter("password");
//检测用户名和密码在数据库中是否存在
List<User> list = DB.getAll();
for(User user : list){
if(user.getUsername().equals(username) && user.getPassword().equals(password)){
//从数据库中找到匹配用户，让用户登陆成功
request.getSession().setAttribute("user", user);
response.sendRedirect("/day07/index.jsp");
return;
}
}
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
response.getWriter().write("用户名或密码错误！！");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
class DB{
private static List<User> list = new ArrayList();
static{
list.add(new User("aaa","123"));
list.add(new User("bbb","123"));
list.add(new User("ccc","123"));
list.add(new User("ddd","123"));
}
public static List getAll(){
return list;
}
}
package cn.itcast.login;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//注销登陆用户
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession(false);
if(session!=null){
session.removeAttribute("user");
}
response.sendRedirect("/day07/index.jsp");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
<form action="/day07/servlet/LoginServlet" method="post"> 用户名：<input type="text" name="username"><br/> 密码：<input type="password" name="password"><br/> <input type="submit" value="登陆"> </form>
<body>
欢迎您：
<%
User user = (User)session.getAttribute("user");
if(user!=null)
out.write(user.getUsername());
%>
<a href="/day07/servlet/LogoutServlet">注销</a>
</body>原文地址：http://blog.csdn.net/u010590318/article/details/40756959
