Filter过滤器自动登入

使用Servlet实现自动登入

form表单

<form class="form-horizontal" action="${pageContext.request.contextPath }/login" method="post">
						<div class="form-group">
							<label for="username" class="col-sm-2 control-label">用户名</label>
							<div class="col-sm-6">
								<input type="text" class="form-control" id="username" name="username"
									placeholder="请输入用户名">
							</div>
						</div>
						<div class="form-group">
							<label for="inputPassword3" class="col-sm-2 control-label">密码</label>
							<div class="col-sm-6">
								<input type="password" class="form-control" id="inputPassword3" name="password"
									placeholder="请输入密码">
							</div>
						</div>
						<div class="form-group">
							<label for="inputPassword3" class="col-sm-2 control-label">验证码</label>
							<div class="col-sm-3">
								<input type="text" class="form-control" id="inputPassword3"
									placeholder="请输入验证码">
							</div>
							<div class="col-sm-3">
								<img src="./image/captcha.jhtml" />
							</div>
						</div>
						<div class="form-group">
							<div class="col-sm-offset-2 col-sm-10">
								<div class="checkbox">
									<label> <input type="checkbox" name="autoLogin" value="autoLogin"> 自动登录
									</label>      <label> <input
										type="checkbox"> 记住用户名
									</label>
								</div>
							</div>
						</div>
						<div class="form-group">
							<div class="col-sm-offset-2 col-sm-10">
								<input type="submit" width="100" value="登录" name="submit"
									style="background: url('./images/login.gif') no-repeat scroll 0 0 rgba(0, 0, 0, 0); height: 35px; width: 100px; color: white;">
							</div>
						</div>
					</form>

跳转index.jsp显示用户

                       <c:if test="${empty user }">
				<li><a href="login.jsp">登录</a></li>
				<li><a href="register.jsp">注册</a></li>
			</c:if>
			<c:if test="${!empty user }">
				<li>欢迎您,${user.username }</li>
				<li><a href="#">退出</a></li>
			</c:if>

 web层

package com.ithiema.web.servlet;

import java.io.IOException;
import java.net.URLEncoder;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.ithiema.domain.User;
import com.ithiema.service.UserService;

public class LoginServlet extends HttpServlet {

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		request.setCharacterEncoding("UTF-8");
		
		HttpSession session = request.getSession();
		
		//获取数据
		String username = request.getParameter("username");//中文 张三
		String password = request.getParameter("password");
		
		UserService service = new UserService();
		User user = null;
		try {
			user = service.login(username,password);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		
		
		if(user!=null){
			//登录成功
			//判断用户是否勾选自动登录
			String autoLogin = request.getParameter("autoLogin");
			if(autoLogin!=null){
				
				//对中文张三进行编码
				String username_code = URLEncoder.encode(username, "UTF-8");// %AE4%kfj
				
				Cookie cookie_username = new Cookie("cookie_username",username_code);
				Cookie cookie_password = new Cookie("cookie_password",password);
				//设置cookie的持久化时间
				cookie_username.setMaxAge(60*60);
				cookie_password.setMaxAge(60*60);
				//设置cookie的携带路径
				cookie_username.setPath(request.getContextPath());
				cookie_password.setPath(request.getContextPath());
				//发送cookie
				response.addCookie(cookie_username);
				response.addCookie(cookie_password);
			}
			
			//将登录的用户的user对象存到session中
			session.setAttribute("user", user);
			//重定向到首页
			response.sendRedirect(request.getContextPath());
			
		}else{
			//失败 转发到登录页面 提出提示信息
			request.setAttribute("loginInfo", "用户名或密码错误");
			request.getRequestDispatcher("/login.jsp").forward(request, response);
		}
		
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}

service层

package com.ithiema.service;

import java.sql.SQLException;

import com.ithiema.dao.UserDao;
import com.ithiema.domain.User;

public class UserService {

	public User login(String username, String password) throws SQLException {
		UserDao dao = new UserDao();
		return dao.login(username,password);
	}

}

Dao层

package com.ithiema.dao;

import java.sql.SQLException;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;

import com.ithiema.domain.User;
import com.ithiema.utils.DataSourceUtils;

public class UserDao {

	public User login(String username, String password) throws SQLException {
		
		QueryRunner runner = new QueryRunner(DataSourceUtils.getDataSource());
		String sql = "select * from user where username=? and password=?";
		return runner.query(sql, new BeanHandler<User>(User.class), username,password);
		
	}

}

 Filter层

package com.ithiema.web.filter;

import java.io.IOException;
import java.net.URLDecoder;
import java.sql.SQLException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.ithiema.domain.User;
import com.ithiema.service.UserService;

public class AutoLoginFilter implements Filter{

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		HttpSession session = req.getSession();
		
		//获得cookie中用户名和密码 进行登录的操作
		//定义cookie_username
		String cookie_username = null;
		//定义cookie_password
		String cookie_password = null;
		//获得cookie
		Cookie[] cookies = req.getCookies();
		if(cookies!=null){
			for(Cookie cookie : cookies){
				//获得名字是cookie_username和cookie_password
				if("cookie_username".equals(cookie.getName())){
					cookie_username = cookie.getValue();
					//恢复中文用户名
					cookie_username = URLDecoder.decode(cookie_username, "UTF-8");
				}
				if("cookie_password".equals(cookie.getName())){
					cookie_password = cookie.getValue();
				}
			}
		}
		
		//判断username和password是否是null
		if(cookie_username!=null&&cookie_password!=null){
			//登录的代码
			UserService service = new UserService();
			User user = null;
			try {
				user = service.login(cookie_username,cookie_password);
			} catch (SQLException e) {
				e.printStackTrace();
			}
			//将登录的用户的user对象存到session中
			session.setAttribute("user", user);
		}
		
		//放行
		chain.doFilter(req, resp);
		
	}
	
	
	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		
	}

	@Override
	public void destroy() {
		
	}

	
	
}

在web.xml中配置Filter

  <!-- 自动登录的filter -->
 <filter>
  	<filter-name>AutoLoginFilter</filter-name>
  	<filter-class>com.ithiema.web.filter.AutoLoginFilter</filter-class>
  </filter>
  <filter-mapping>
  	<filter-name>AutoLoginFilter</filter-name>
  	<url-pattern>/*</url-pattern>
  </filter-mapping>

User实体类

package com.ithiema.domain;

public class User {

	private int id;
	private String username;
	private String password;
	private String email;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	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;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	
	
	
}