JS第十一次1作业

1>cookie,实现登录的时候，记住我

2>filter：实现编码过滤器。

​ 思考 如何实现访问servlet的时候，必须登录后才能访问。

1.

serverIn.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


    用户信息
<%
    Cookie[] cookies = request.getCookies();
    if (cookies != null){
        System.out.println(cookies.length);
        for (int i = 0; i < cookies.length; i++){
            if (cookies[i].getName() != null &&cookies[i].getValue() != null);
            response.sendRedirect("serverShow.do");
        }
    }


%>

loginServer.java:

package action;


import dao.UsersDao;
import impl.UsersDaoImpl;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


@WebServlet(urlPatterns = "/login.do")
public class loginServer extends HttpServlet {
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

    }

    protected  void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
        req.setCharacterEncoding("UTF-8");
        String name = req.getParameter("user_name");
        String password = req.getParameter("password");
        String re = req.getParameter("remember");
        if (re != null){
            Cookie cookie_N = new Cookie("name",name);
            Cookie cookie_P = new Cookie("name",password);
            cookie_N.setMaxAge(60);
            cookie_P.setMaxAge(60);
            resp.addCookie(cookie_N);
            resp.addCookie(cookie_P);
        }

        UsersDao usersDao = new UsersDaoImpl();
        boolean yn = usersDao.find(name, password);
        if (yn){
            resp.sendRedirect("serverShow.do");
        }else {
            req.setAttribute("wrong", "用户名或密码错误");
            req.getRequestDispatcher("serverLogin.jsp").forward(req, resp);
        }
        req.setAttribute("user",yn);
    }
}

2.

CodeFilter.java:

package utils;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

public class CodeFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        request.setCharacterEncoding("UTF-8");
        filterChain.doFilter(servletRequest, servletResponse);
    }
    public void init(FilterConfig filterConfig) throws ServletException{

    }
}

MyFilter.java:

package utils;

import javax.servlet.*;
import java.io.IOException;

public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
    }
}

选中“自动登录”后可跳过登陆界面：