Map<String, HttpSession> map=(Map<String, HttpSession>) getServletContext().getAttribute("users");

最新推荐文章于 2023-05-05 20:25:45 发布
最新推荐文章于 2023-05-05 20:25:45 发布 · 237 阅读 · 0
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#java

本文介绍了一个简单的Servlet实现，用于从服务器会话中踢出指定用户名的用户。通过获取请求参数中的用户名，从服务器上下文获取用户会话映射，并移除对应的会话。
package com.tfy.heima.servlet;


import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;


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


public class KickServlet extends HttpServlet {


public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {


response.setContentType("text/html;charset=UTF-8");
PrintWriter out=response.getWriter();
String username=request.getParameter("username");

username=new String(username.getBytes("ISO-8859-1"),"UTF-8");
Map<String, HttpSession> map=(Map<String, HttpSession>) getServletContext().getAttribute("users");

HttpSession session=map.get(username);
if(session!=null){
session.removeAttribute("user");
map.remove(username);
}
out.write("踢出成功");
}


public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {


doGet(request, response);
}


}
iteye_4515
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<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>登录页面</title> <style> .login-box { width: 300px; margin: 100px auto; padding: 20px; border: 1px solid #eee; border-radius: 8px; } input { width: 100%; padding: 8px; margin: 8px 0; box-sizing: border-box; } .btn { background: #0084ff; color: white; border: none; border-radius: 4px; cursor: pointer; } .error { color: red; text-align: center; } </style> </head> <body> <div class="login-box"> <form action="loginCheck.jsp" method="post"> 用户名: <input type="text" name="username" required placeholder="请输入用户名"><br> 密码: <input type="password" name="password" required placeholder="请输入密码"><br> <input type="submit" class="btn" value="登录"> <% String error = request.getParameter("error"); %> <% if (error != null && "1".equals(error)) { %> <div class="error">用户名或密码错误</div> <% } %> </form> </div> </body> </html><%@ page contentType="text/html;charset=UTF-8" language="java" %> <%@ page import="java.sql.*" %> <%@ page import="org.mindrot.jbcrypt.BCrypt" %> <% request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); String username = request.getParameter("username"); String password = request.getParameter("password"); if (username == null || username.trim().isEmpty() || password == null || password.trim().isEmpty()) { response.sendRedirect("login.jsp?error=1"); return; } username = username.trim(); password = password.trim(); // ########## 请修改这里的数据库配置（改为你的 MySQL 信息）########## String driver = "com.mysql.cj.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/yourdb?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true"; String dbUser = "root"; // 你的 MySQL 用户名（默认 root） String dbPwd = "123456"; // 你的 MySQL 密码（安装时设置的） // ########################################################### Connection conn = null; PreparedStatement ps = null; ResultSet rs = null; try { Class.forName(driver); conn = DriverManager.getConnection(url, dbUser, dbPwd); String sql = "SELECT password FROM users WHERE username = ?"; ps = conn.prepareStatement(sql); ps.setString(1, username); rs = ps.executeQuery(); if (rs.next()) { String dbPwdHash = rs.getString("password"); if (BCrypt.checkpw(password, dbPwdHash)) { session.setAttribute("username", username); session.setMaxInactiveInterval(30 * 60); response.sendRedirect("welcome.jsp"); } else { response.sendRedirect("login.jsp?error=1"); } } else { response.sendRedirect("login.jsp?error=1"); } } catch (ClassNotFoundException e) { System.err.println("数据库驱动加载失败：" + e.getMessage()); response.sendRedirect("login.jsp?error=1"); } catch (SQLException e) { System.err.println("数据库错误：" + e.getMessage()); response.sendRedirect("login.jsp?error=1"); } catch (Exception e) { System.err.println("系统错误：" + e.getMessage()); response.sendRedirect("login.jsp?error=1"); } finally { if (rs != null) try { rs.close(); } catch (SQLException e) {} if (ps != null) try { ps.close(); } catch (SQLException e) {} if (conn != null) try { conn.close(); } catch (SQLException e) {} } %><%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>欢迎页面</title> <style> .welcome { text-align: center; margin-top: 100px; } a { color: #0084ff; text-decoration: none; } a:hover { text-decoration: underline; } </style> </head> <body> <% String username = (String) session.getAttribute("username"); if (username == null || username.trim().isEmpty()) { response.sendRedirect("login.jsp"); return; } %> <div class="welcome"> <h1>欢迎回来，<%= username %>！</h1> <br> <a href="logout.jsp">安全注销</a> </div> </body> </html><%@ page contentType="text/html;charset=UTF-8" language="java" %> <% session.invalidate(); response.sendRedirect("login.jsp"); %>
最新发布
11-25
<style>...</style> </head> <body> <div class="login-box"> <form action="loginCheck.jsp" method="post"> 用户名: <input type="text" name="username" required placeholder="请输入用户名"><br> 密码: ...
package com.kuls.controller.admin; import com.github.pagehelper.PageHelper; import com.github.pagehelper.PageInfo; import com.kuls.po.Blog; import com.kuls.po.User; import com.kuls.service.admin.BlogService; import com.kuls.service.admin.TagService; import com.kuls.service.admin.TypeService; import com.kuls.vo.BlogQuery; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.*; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.servlet.mvc.support.RedirectAttributes; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import java.io.File; import java.util.HashMap; import java.util.List; import java.util.Map; //这个控制器类提供了后台博客管理的一系列功能，包括博客列表展示、搜索、编辑、保存、更新、删除以及图片上传等操作。 @Controller//Spring MVC 的控制器类，用于处理与博客管理相关的请求 @RequestMapping("/admin")//所有路径以/admin开头 public class BlogAdminController { @Autowired private BlogService blogService; @Autowired private TypeService typeService; @Autowired private TagService tagService; /** * 后台显示博客列表 * * @param pageNum 显示第几页 * @param pageSize 每页展示的数量 * @param model 前端model * @return */ @GetMapping("/blogs") public String toBlogs(@RequestParam(defaultValue = "1") int pageNum, @RequestParam(defaultValue = "5") int pageSize, Model model) { PageHelper.startPage(pageNum, pageSize);//使用PageHelper进行分页 //传递一个空对象即可 BlogQuery blog = new BlogQuery(); List<Blog> lists = blogService.listBlog(blog); PageInfo<Blog> blogPageInfo = new PageInfo<>(lists); model.addAttribute("blogs", blogPageInfo); model.addAttribute("types", typeService.listType()); // mybatis plus return "admin/blogs"; } /** * 后台博客搜索功能 * * @param pageNum * @param pageSize * @param blog * @param model * @return */ @PostMapping("/blogs/search") public String search(@RequestParam(defaultValue = "1") int pageNum, @RequestParam(defaultValue = "5") int pageSize, BlogQuery blog, Model model) { PageHelper.startPage(pageNum, pageSize); // 根据BlogQuery对象的属性来进行查询 List<Blog> lists = blogService.listBlog(blog); PageInfo<Blog> blogPageInfo = new PageInfo<>(lists); model.addAttribute("blogs", blogPageInfo); model.addAttribute("types", typeService.listType()); return "admin/blogs :: blogList"; } /** * 博客编辑和发表 * * @param model * @return */ @GetMapping("/blogs/input") public String input(Model model) { model.addAttribute("types", typeService.listType()); model.addAttribute("tags", tagService.listTag()); model.addAttribute("blog", new Blog());//所有博客类型和标签添加到Model中，并添加一个空的Blog对象，用于在视图中初始化表单。 return "admin/blogs-input"; } /** * 更新编辑博客 * * @param id 指定博客的id * @param model * @return */ @GetMapping("/blogs/{id}/update") public String editBlog(@PathVariable long id, Model model) { model.addAttribute("types", typeService.listType()); model.addAttribute("tags", tagService.listTag()); Blog blog = blogService.getBlogByID(id); model.addAttribute("blog", blog); return "admin/blogs-input"; } /** * 保存或者发布博客 * * @param blog * @param session * @param attributes * @return */ @PostMapping("/blogs/save") public String save(Blog blog, HttpSession session, RedirectAttributes attributes) { User user = (User) session.getAttribute("user"); // 获取当前用户 if (user != null){ blog.setUser(user); blog.setType(typeService.getType(blog.getType().getId())); blog.setTages(tagService.listTag(blog.getTagIds())); int save = blogService.save(blog); if (save > 0) { attributes.addFlashAttribute("msg", "操作成功"); } else { attributes.addFlashAttribute("errormsg", "操作失败"); } return "redirect:/admin/blogs"; }else { return "redirect:/admin/index"; } } /** * 更新博客 * * @param blog * @param session * @param attributes * @return */ @PostMapping("/updateBlogs") public String updateBlogs(Blog blog, HttpSession session, RedirectAttributes attributes) { blog.setUser((User) session.getAttribute("user")); blog.setType(typeService.getType(blog.getType().getId())); blog.setTages(tagService.listTag(blog.getTagIds())); int update = blogService.updateBlog(blog); if (update > 0) { attributes.addFlashAttribute("msg", "操作成功"); } else { attributes.addFlashAttribute("errormsg", "操作失败"); } return "redirect:/admin/blogs"; } /** * 删除博客 * * @param id * @param redirectAttributes * @return */ @GetMapping("/blogs/{id}/delete") public String deleteBlog(@PathVariable Long id, RedirectAttributes redirectAttributes) { int i = blogService.deleteBlog(id); if (i > 0) { redirectAttributes.addFlashAttribute("msg", "删除成功！"); } else { redirectAttributes.addFlashAttribute("errormsg", "删除失败！"); } return "redirect:/admin/blogs"; } /** * 博客内容中插入的图片 * @param file * @param request * @return */ @PostMapping(value = "/uploadfile") @ResponseBody public Map<String,Object> demo(@RequestParam(value = "editormd-image-file", required = false) MultipartFile file, HttpServletRequest request) { Map<String,Object> resultMap = new HashMap<String,Object>(); //保存 try { File imageFolder= new File(request.getServletContext().getRealPath("img/upload/blog/")); File targetFile = new File(imageFolder,file.getOriginalFilename()); if(!targetFile.getParentFile().exists()){ targetFile.mkdirs(); } // 将文件写入targetFile中 file.transferTo(targetFile); resultMap.put("success", 1); resultMap.put("message", "上传成功！"); resultMap.put("url","/img/upload/blog/"+file.getOriginalFilename()); } catch (Exception e) { resultMap.put("success", 0); resultMap.put("message", "上传失败！"); e.printStackTrace(); } return resultMap; } } package com.kuls.controller.front; import com.kuls.exception.BlogNotFoundException; import com.kuls.mapper.BlogTagMapper; import com.kuls.po.Blog; import com.kuls.service.CommentService; import com.kuls.service.admin.BlogService; import com.kuls.service.admin.LinkService; import com.kuls.service.admin.TagService; import com.kuls.service.admin.TypeService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class BlogFrontController { @Autowired private BlogService blogService; @Autowired private TagService tagService; @Autowired private BlogTagMapper blogTagMapper; @Autowired private LinkService linkService; /** * 显示指定博客详情信息 * * @param id * @param model * @return */ @GetMapping({"/blog/{id}"}) public String blogDetail( @PathVariable long id, Model model) { Blog blog = blogService.getBlogOnfront(id); if (blog == null){ throw new BlogNotFoundException("很抱歉，这篇博客不存在~"); } blogService.incView(id); model.addAttribute("blog", blog); model.addAttribute("tags", tagService.listTag(blogTagMapper.selectByBlogId(id))); model.addAttribute("links", linkService.listAllOnFront()); return "blog"; } } package com.kuls.mapper; import com.kuls.po.Blog; import com.kuls.vo.BlogQuery; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Param; import org.springframework.stereotype.Repository; import java.util.List; //接口部分：利用Mybatis框架对数据库表进行增删改查等操作 @Mapper//对MyBatis框架的注解，用于标记该接口为 MyBatis 的 Mapper 接口，Spring 会自动扫描并为其生成代理实现，使得接口方法能够与 SQL 语句进行绑定，从而实现对数据库的操作。 @Repository//Spring 框架的注解，用于将该接口标记为数据访问组件。它主要用于将数据访问层的异常转换为 Spring 统一的数据访问异常体系，同时便于将该组件纳入 Spring 的依赖注入和事务管理体系。 public interface BlogMapper { Blog getBlogByID(Long id);//根据传入的博客id获取博客信息 //查出所有博客 List<Blog> listBlog(BlogQuery blog); //查出所有博客显示在前端页面 List<Blog> listBlogOnFront(BlogQuery blog); //热门文章查询 List<Blog> listBlogOnFrontHot(BlogQuery blog); //实现博客阅读数的增加 int incView(Blog blog); //实现博客喜欢数的增加 int incLikes(Blog blog); int save(Blog blog);//保存博客 int updateBlog(Blog blog);//修改、更新博客 int deleteBlog(@Param("id") Long id);//删除博客 } package com.kuls.po; import com.fasterxml.jackson.annotation.JsonFormat; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; import org.springframework.format.annotation.DateTimeFormat; import java.util.Date; import java.util.List; //Blog 类是一个 Java POJO（Plain Old Java Object），用于表示博客系统中的博客实体。 // 它包含了博客的各种属性，如基本信息、发布状态、时间戳、关联的类型、标签、用户以及评论等，通过这些属性全面地描述了一个博客的相关信息，为博客系统的业务逻辑和数据传输提供了数据载体。 @Data @AllArgsConstructor @NoArgsConstructor public class Blog { private Long id; private String title; private String content; private String firstPicture; private String flag; private Integer view; private Integer likes; private String description; private boolean appreciation; private boolean shareStatement; private boolean commentabled; private boolean published; private boolean recommend; @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")//使用 @JsonFormat 注解确保在序列化时按照指定格式和时区展示。 private Date createTime; private Date updateTime; private Type type; private List<Tag> tages; //tagIds不会进入数据库 private String tagIds; private User user; private List<Comment> comments; } package com.kuls.service.admin.impl; import com.kuls.exception.BlogNotFoundException; import com.kuls.mapper.BlogMapper; import com.kuls.mapper.BlogTagMapper; import com.kuls.mapper.TagMapper; import com.kuls.po.Blog; import com.kuls.po.Tag; import com.kuls.service.RedisService; import com.kuls.service.admin.BlogService; import com.kuls.service.admin.TagService; import com.kuls.util.MarkdownUtils; import com.kuls.util.MyBeanUtils; import com.kuls.vo.BlogLikedCount; import com.kuls.vo.BlogQuery; import com.kuls.vo.BlogViewCount; import io.lettuce.core.ScriptOutputType; import org.springframework.beans.BeanUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; import java.util.Date; import java.util.List; @Service public class BlogServiceImpl implements BlogService { @Autowired private BlogMapper blogMapper; @Autowired private TagService tagService; @Autowired private BlogTagMapper blogTagMapper; @Autowired private TagMapper tagMapper; @Autowired private RedisService redisService; @Transactional @Override public Blog getBlogByID(Long id) { Blog blog = blogMapper.getBlogByID(id); List<Long> longList = blogTagMapper.selectByBlogId(id); List<Tag> tags = tagMapper.listTag1(longList); String s = tagsToIds(tags); blog.setTagIds(s); return blog; } @Override public Blog getBlogOnfront(Long id) { Blog blog = blogMapper.getBlogByID(id); if (blog == null) { throw new BlogNotFoundException("博客不存在！"); } Blog blog1 = new Blog(); BeanUtils.copyProperties(blog, blog1); String content = blog1.getContent(); blog1.setContent(MarkdownUtils.markdownToHtmlExtensions(content)); return blog1; } //1,2,3 private String tagsToIds(List<Tag> tags) { if (!tags.isEmpty()) { StringBuffer ids = new StringBuffer(); boolean flag = false; for (Tag tag : tags) { if (flag) { ids.append(","); } else { flag = true; } ids.append(tag.getId()); } return ids.toString(); } else { return null; } } @Transactional @Override public int save(Blog blog) { blog.setCreateTime(new Date()); blog.setUpdateTime(new Date()); blog.setLikes(1); blog.setView(1); int save = blogMapper.save(blog); handlerBlogTag(blog.getId(), blog.getTages()); return save; } void handlerBlogTag(Long blogId, List<Tag> tags) { for (Tag tag : tags) { blogTagMapper.insertBlogTag(blogId, tag.getId()); } } @Transactional @Override public List<Blog> listBlog(BlogQuery blog) { return blogMapper.listBlog(blog); } @Transactional @Override public List<Blog> listBlogOnFront(BlogQuery blog) { return blogMapper.listBlogOnFront(blog); } @Override public List<Blog> listBlogOnFrontHot(BlogQuery blog) { return blogMapper.listBlogOnFrontHot(blog); } @Transactional @Override public int incView(long id) { Blog blog = new Blog(); blog.setId(id); return blogMapper.incView(blog); } @Transactional @Override public int incLikes() { List<BlogLikedCount> likedCountsList = redisService.getLikedCountFromRedis(); for (BlogLikedCount count : likedCountsList) { Blog blog = new Blog(); Integer blogId = count.getBlogId(); long l = blogId.longValue(); blog.setId(l); blog.setLikes(count.getAddLikedCount()); System.out.println("这里是like的值：" + count.getAddLikedCount()); blogMapper.incLikes(blog); } return 1; } @Transactional @Override public int updateBlog(Blog blog) { Blog blog1 = blogMapper.getBlogByID(blog.getId()); BeanUtils.copyProperties(blog, blog1, MyBeanUtils.getNullPropertyNames(blog)); blog1.setUpdateTime(new Date()); int update = blogMapper.updateBlog(blog1); //删除所有标签（之后优化） blogTagMapper.delete(blog.getId()); //插入新的标签 handlerBlogTag(blog.getId(), blog.getTages()); return update; } @Transactional @Override public int deleteBlog(Long id) { return blogMapper.deleteBlog(id); } } package com.kuls.service.admin; import com.kuls.po.Blog; import com.kuls.vo.BlogQuery; import java.util.List; public interface BlogService { Blog getBlogByID(Long id); Blog getBlogOnfront(Long id); int save(Blog blog); //查出所有博客 List<Blog> listBlog(BlogQuery blog); List<Blog> listBlogOnFront(BlogQuery blog); //热门文章 List<Blog> listBlogOnFrontHot(BlogQuery blog); //实现博客阅读数的增加 int incView(long id); //批量增加博客喜欢数 int incLikes(); int updateBlog(Blog blog); int deleteBlog(Long id); } <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <!--指定该映射文件对应的接口--> <mapper namespace="com.kuls.mapper.BlogMapper"> <!--根据id获取文章 paramaterType 指定传入参数为long类型的博客ID，resultMap指定使用BlogMap进行结果映射--> <select id="getBlogByID" parameterType="long" resultMap="BlogMap"> select id,title,content,first_picture,likes, flag,view,description,appreciation,share_statement,commentabled,published, recommend, create_time ,update_time ,type_id from t_blog where id=#{id}; </select> <!--给前端页面显示的博客文章:已发布的--> <select id="listBlogOnFront" resultMap="BlogMap"> select id,title,content,first_picture,likes, flag,view,description,appreciation,share_statement,commentabled,published, recommend, create_time ,update_time ,type_id from t_blog -- 选择已经发布的博客，其中标题模糊查询、推荐状态精准查询、类型id精准查询 <where> and published = true <if test="title != null and title != ''"> and title like concat('%',#{title},'%') </if> <if test="recommend != null and recommend != ''"> and recommend = #{recommend} </if> <if test="typeId != null and typeId != ''"> and type_id = #{typeId} </if> </where> order by update_time DESC </select> <!--给前端页面显示的博客文章:热门的前五--> <select id="listBlogOnFrontHot" resultMap="BlogMap"> select id,title,content,first_picture,likes, flag,view,description,appreciation,share_statement,commentabled,published, recommend, create_time ,update_time ,type_id from t_blog <where> and published = true </where> order by view DESC limit 0,5<!--降序排序，显示前5条--> </select> <!--后台获取博客信息、用于后台管理--> <select id="listBlog" resultMap="BlogMap"> select id,title,content,first_picture,likes, flag,view,description,appreciation,share_statement,commentabled,published, recommend, create_time ,update_time ,type_id from t_blog <where> <if test="title != null and title != ''"> and title like concat('%',#{title},'%')<!--标题模糊查询--> </if> <if test="recommend != null and recommend != ''"> and recommend = #{recommend}<!--推荐状态精准查询--> </if> <if test="typeId != null and typeId != ''"> and type_id = #{typeId}<!--//类型id精准查询--> </if> </where> order by update_time DESC </select> <!--使用id分别获取博客类型和用户信息--> <select id="getType" resultType="Type"> select * from t_type where id=#{id}; </select> <select id="getUser" resultType="User"> select * from t_user where id=#{id}; </select> <!--BlogMap结果映射--> <resultMap id="BlogMap" type="Blog"> <result property="id" column="id"/> <result property="title" column="title"/> <result property="content" column="content"/> <result property="firstPicture" column="first_picture"/> <result property="flag" column="flag"/> <result property="view" column="view"/> <result property="appreciation" column="appreciation"/> <result property="shareStatement" column="share_statement"/> <result property="commentabled" column="commentabled"/> <result property="published" column="published"/> <result property="recommend" column="recommend"/> <result property="createTime" column="create_time"/> <result property="updateTime" column="update_time"/> <result property="description" column="description"/> <result property="likes" column="likes"/> <association property="type" column="type_id" javaType="Type" select="getType"> <result property="name" column="tname"/> </association> </resultMap> <!--useGeneratedKeys="true" keyProperty="id" 这两个属性会返回id主键的值--> <!--通过 MyBatis 实现了将一个新的博客记录插入到t_blog表中， 并在插入成功后获取数据库自动生成的主键值填充到传入的Blog对象的id属性中--> <insert id="save" parameterType="Blog" useGeneratedKeys="true" keyProperty="id"> insert into t_blog(id,title,content,first_picture,likes, flag,view,description,appreciation,share_statement,commentabled,published, recommend,create_time,update_time,type_id,user_id) values (#{id}, #{title},#{content},#{firstPicture},#{likes},#{flag},#{view},#{description},#{appreciation},#{shareStatement}, #{commentabled},#{published},#{recommend},#{createTime},#{updateTime},#{type.id},#{user.id} ); 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