4.23

过滤器

内容：
1.过滤器
2.正则表达式
3.log4j
4.Servelt
5.多表联合查询

日期：2020.04.23
作者：爱猫狗的小郝_河南济源

package hsy.cool.filter;

import hsy.cool.util.MybatisUtils;
import org.apache.log4j.Logger;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.util.regex.Pattern;

@WebFilter(urlPatterns = "/*",filterName = "SqlSessionFilter")
public class SqlSessionFilter implements Filter {
    String regex="(/\\w+)*/\\w+\\.(jpg|png|mp4|mp3|rm)";
    //日志
    Logger log4j=Logger.getLogger(SqlSessionFilter.class);
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
         servletRequest.setCharacterEncoding("utf-8");
         HttpServletRequest hReq=(HttpServletRequest)servletRequest;
         //https://127.0.0.1:8080/haosiyuan/a.html|a.js|a.jsp|a.jpg  a/b/c/s/sada.jsp
         String path=hReq.getServletPath();
         boolean mattch=Pattern.matches(regex,path);
         log4j.debug(hReq.getRemoteAddr()+"request["+path+"]open SqlSession……");
         if(path!=null&&!mattch){
             try {
                 //1.请求
                 MybatisUtils.open();
                 log4j.debug(hReq.getRemoteAddr()+"request["+path+"]start SqlSession……");
                 //2.目标
                 //放行
                 filterChain.doFilter(servletRequest,servletResponse);
                 log4j.debug(hReq.getRemoteAddr()+"request["+path+"]end SqlSession……");
             }catch (Exception e){
                 MybatisUtils.rollback();
                 log4j.debug(hReq.getRemoteAddr()+"request["+path+"]Exception"+e);
                 throw e;//为何要显示抛一个异常？
             }finally {
                 //3.释放
                 MybatisUtils.close();
                 log4j.debug(hReq.getRemoteAddr()+"request["+path+"]close SqlSession……");
             }

         }else {
             //放行
             filterChain.doFilter(servletRequest,servletResponse);
         }
        log4j.debug(hReq.getRemoteAddr()+"request["+path+"]end!!!!!!!!!!!!!!!!!!!!!!! SqlSession……");



    }

    @Override
    public void destroy() {

    }
}

web

UsersServelt

package hsy.cool.web;

import hsy.cool.bean.Users;
import hsy.cool.dao.UsersMapper;
import hsy.cool.util.MybatisUtils;

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 java.io.IOException;

@WebServlet(urlPatterns = "/user",name = "UsersServelt")
public class UsersServelt extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       req.setCharacterEncoding("utf-8");
       String name=req.getParameter("account");
       String pwd=req.getParameter("pwd");
       Users user=MybatisUtils.getMapper(UsersMapper.class).findByName(name);
       if(user!=null&&user.getPwd().equals(pwd)){
           resp.sendRedirect("/webAC_war_exploded/index.jsp");
       }else {
           resp.sendRedirect("/webAC_war_exploded/login.jsp");
       }
    }
}

NewsServelt

package hsy.cool.web;

import hsy.cool.bean.News;
import hsy.cool.dao.NewsMapper;
import hsy.cool.util.MybatisUtils;

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 java.io.IOException;
import java.util.List;

@WebServlet(urlPatterns = "/list",name = "NewsServelt")
public class NewsServelt extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       req.setCharacterEncoding("utf-8");
       NewsMapper newsDao=MybatisUtils.getMapper(NewsMapper.class);
       List<News> list=newsDao.findAll();
       req.setAttribute("list",list);
       req.getRequestDispatcher("/news/list.jsp").forward(req,resp);
    }
}

日期工具类

package hsy.cool.util;

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateUtils {
    static SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    public static String parse(Date date){
        return df.format(date);
    }
}

Bean

package hsy.cool.bean;




import hsy.cool.util.DateUtils;


import java.util.Date;

public class News {
    private int id;
    private String title;
    private String content;
    private int users_id;
    private int category_id;
    private Date pubtime;
    private String keywords;
    private  int state;
    private int check_users_id;
    private Date check_time;
    private int is_elite;
    private String usersName;
    private String categoryName;
    private String checkUsersName;

    public String getPubtimeString(){
        return DateUtils.parse(pubtime);
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public int getUsers_id() {
        return users_id;
    }

    public void setUsers_id(int users_id) {
        this.users_id = users_id;
    }

    public int getCategory_id() {
        return category_id;
    }

    public void setCategory_id(int category_id) {
        this.category_id = category_id;
    }

    public Date getPubtime() {
        return pubtime;
    }

    public void setPubtime(Date pubtime) {
        this.pubtime = pubtime;
    }

    public String getKeywords() {
        return keywords;
    }

    public void setKeywords(String keywords) {
        this.keywords = keywords;
    }

    public int getState() {
        return state;
    }

    public void setState(int state) {
        this.state = state;
    }

    public int getCheck_users_id() {
        return check_users_id;
    }

    public void setCheck_users_id(int check_users_id) {
        this.check_users_id = check_users_id;
    }

    public Date getCheck_time() {
        return check_time;
    }

    public void setCheck_time(Date check_time) {
        this.check_time = check_time;
    }

    public int getIs_elite() {
        return is_elite;
    }

    public void setIs_elite(int is_elite) {
        this.is_elite = is_elite;
    }

    public String getUsersName() {
        return usersName;
    }

    public void setUsersName(String usersName) {
        this.usersName = usersName;
    }

    public String getCategoryName() {
        return categoryName;
    }

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }

    public String getCheckUsersName() {
        return checkUsersName;
    }

    public void setCheckUsersName(String checkUsersName) {
        this.checkUsersName = checkUsersName;
    }
}

Dao

NewsMapper

package hsy.cool.dao;

import hsy.cool.bean.News;

import java.util.List;

public interface NewsMapper {
    void delete(int id);

    List<News> findAll();
}

NewsMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--!DOCTYPE configuration SYSTEM "mybatis-3-config.dtd" -->
<mapper namespace="hsy.cool.dao.NewsMapper">
    <!--删除-->
    <delete id="delete" parameterType="int">
        delete from n_news where id=#{id}
    </delete>
    <select id="findAll" resultType="hsy.cool.bean.News">
        select
        n.id,
        title,
        content,
        users_id,
        u.nickname usersName,
        category_id,
        c.name categoryName,
        pubtime,
        keywords,
        state,
        check_users_id,
        u1.nickname checkUsersName,
        is_elite
         from n_news n inner join n_users u on n.users_id=u.id
                       inner join n_category c on n.category_id=c.id
                       inner join n_users u1 on n.check_users_id=u1.id

    </select>

</mapper>

jsp页面

index.jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>首页</title>
  </head>
  <body>
    <p>
    <h1>  首页</h1>
    </p>

   <h2>欢迎登录！</h2>
   <ul>
     <li><a href="/webAC_war_exploded/list">新闻</a></li>
   </ul>
  </body>
</html>

login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>登录</title>
  </head>
  <body>
  <h1>登录页面</h1>
  <form action="/webAC_war_exploded/user" method="post">
    <p>
    账号：<input type="text" name="account" />
    </p>
    <p>
      密码： <input type="password" name="pwd">
    </p>
    <p>
      <input type="submit" value="登录">
    </p>
  </form>
  </body>
</html>

list.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>新闻列表</title>
</head>
<body>
<p>首页/新闻</p>
<h1>新闻列表</h1>
  <table width="1000" border="1">
      <tr>
          <th>编号</th>
          <th>标题</th>
          <th>内容</th>
          <th>分类</th>
          <th>作者</th>
          <th>关键字</th>
          <th>发布时间</th>
          <th>审批</th>
      </tr>
      <c:forEach items="${list}" var="news">
      <tr>
          <td>${news.id}</td>
          <td>${news.title}</td>
          <td>${news.content}</td>
          <td>${news.categoryName}</td>
          <td>${news.usersName}</td>
          <td>${news.keywords}</td>
          <td>${news.pubtimeString}</td>
          <td>${news.checkUsersName}</td>
      </tr>
      </c:forEach>

  </table>
</body>
</html>