jsp要如何直接显示数据库里信息
想用java做电影推荐网站，网站首页是jsp，想在首页显示数据库里的电影信息，应该怎么操作？
是用servlet吗，我在servlet写了个读取数据库电影信息并输出，存到了list，然后jsp里怎么转到servlet并显示信息呀
想要实现成主页大概是这个样子
这有个案例，流程就是读取数据库中的数据显示到jsp页面，很简单
- 这有个类似的问题, 你可以参考下: https://ask.csdn.net/questions/768870
- 这篇博客也不错, 你可以看下【初学JavaEE】jsp、servlet如何实现页面跳转
- 除此之外, 这篇博客: 列表查询，添加功能---JSP，servlet中的 9.编写查询后的list.jsp页面 部分也许能够解决你的问题, 你可以仔细阅读以下内容或跳转源博客中阅读:
将查询的数据库所有用户信息封装到user中，存储到request域中
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html> <!-- 网页使用的语言 --> <html lang="zh-CN"> <head> <!-- 指定字符集 --> <meta charset="utf-8"> <!-- 使用Edge最新的浏览器的渲染方式 --> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。 width: 默认宽度与设备的宽度相同 initial-scale: 初始的缩放比，为1:1 --> <meta name="viewport" content="width=device-width, initial-scale=1"> <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ --> <title>用户信息管理系统</title> <!-- 1. 导入CSS的全局样式 --> <link href="css/bootstrap.min.css" rel="stylesheet"> <!-- 2. jQuery导入，建议使用1.9以上的版本 --> <script src="js/jquery-2.1.0.min.js"></script> <!-- 3. 导入bootstrap的js文件 --> <script src="js/bootstrap.min.js"></script> <style type="text/css"> td, th { text-align: center; } </style> <script type="text/javascript"> function deluser(i) { //用户安全提示 if(confirm("您确定需要删除吗?")){ location.href="${pageContext.request.contextPath }/delUserServlet?id="+i; } } </script> </head> <body> <div class="container"> <h3 style="text-align: center">用户信息列表</h3> <div style="float: left;"> <form class="form-inline"> <div class="form-group"> <label for="exampleInputName2">姓名</label> <input type="text" class="form-control" id="exampleInputName2" > </div> <div class="form-group"> <label for="exampleInputName3">籍贯</label> <input type="text" class="form-control" id="exampleInputName3" > </div> <div class="form-group"> <label for="exampleInputEmail2">邮箱</label> <input type="email" class="form-control" id="exampleInputEmail2" > </div> <button type="submit" class="btn btn-default">查询</button> </form> </div> <div style="float: right; margin: 5px;"> <a class="btn btn-primary" href="${pageContext.request.contextPath }/add.jsp">添加联系人</a> <a class="btn btn-primary" href="delete.jsp">删除选中</a> </div> <table border="1" class="table table-bordered table-hover"> <tr class="success"> <th><input type="checkbox"></th> <th>编号</th> <th>姓名</th> <th>性别</th> <th>年龄</th> <th>籍贯</th> <th>QQ</th> <th>邮箱</th> <th>操作</th> </tr> <c:forEach items="${list}" var="user" varStatus="s"> <tr> <td><input type="checkbox"></td> <td>${s.count}</td> <td>${user.name}</td> <td>${user.gender }</td> <td>${user.age }</td> <td>${user.address }</td> <td>${user.qq }</td> <td>${user.email }</td> <td><a class="btn btn-default btn-sm" href="${pageContext.request.contextPath }/queryupdate?id=${user.id}">修改</a> <a class="btn btn-default btn-sm" href="javascript:deluser(${user.id});" >删除</a></td> </tr> </c:forEach> </table> <div> <nav aria-label="Page navigation"> <ul class="pagination"> <li> <a href="#" aria-label="Previous"> <span aria-hidden="true">«</span> </a> </li> <li><a href="#">1</a></li> <li><a href="#">2</a></li> <li><a href="#">3</a></li> <li><a href="#">4</a></li> <li><a href="#">5</a></li> <li> <a href="#" aria-label="Next"> <span aria-hidden="true">»</span> </a> </li> <span style="font-size: 25px;margin-left: 5px;"> 共16条记录，共4页 </span> </ul> </nav> </div> </div> </body> </html>展示效果：
注意：这里修改，删除，添加功能还没实现，只是单纯显示所有用户这个页面
- 以下回答由chatgpt基于相关博客总结生成:
解决方案：
- 编写一个servlet用于读取数据库中的电影信息并将其存储到一个列表中，具体代码如下：
public class MovieServlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 读取数据库中的电影信息 List<Movie> movies = MovieDao.getMovies(); // 将电影信息存储到request域中 request.setAttribute("movies", movies); // 转发到jsp页面 request.getRequestDispatcher("/index.jsp").forward(request, response); } }- 在jsp页面中调用该servlet，以便将电影信息显示出来，具体代码如下：
<% // 调用MovieServlet获取电影信息 request.getRequestDispatcher("/MovieServlet").include(request, response); // 获取电影信息 List<Movie> movies = (List<Movie>)request.getAttribute("movies"); %> <table> <tr> <th>电影名称</th> <th>类型</th> <th>演员</th> <th>评分</th> </tr> <% for (Movie movie : movies) { %> <tr> <td><%= movie.getName() %></td> <td><%= movie.getType() %></td> <td><%= movie.getActor() %></td> <td><%= movie.getScore() %></td> </tr> <% } %> </table>- 可以在jsp页面中添加分页功能，具体代码如下：
<% // 调用MovieServlet获取电影信息及分页信息 request.getRequestDispatcher("/MovieServlet?page=<%= request.getParameter("page") %>&pageSize=<%= request.getParameter("pageSize") %>").include(request, response); // 获取电影信息和分页信息 List<Movie> movies = (List<Movie>)request.getAttribute("movies"); PageBean pageBean = (PageBean)request.getAttribute("pageBean"); %> <table> <tr> <th>电影名称</th> <th>类型</th> <th>演员</th> <th>评分</th> </tr> <% for (Movie movie : movies) { %> <tr> <td><%= movie.getName() %></td> <td><%= movie.getType() %></td> <td><%= movie.getActor() %></td> <td><%= movie.getScore() %></td> </tr> <% } %> </table> <div> <% if (pageBean.isHasPreviousPage()) { %> <a href="?page=<%= pageBean.getPreviousPage() %>&pageSize=<%= pageBean.getPageSize() %>">上一页</a> <% } %> <% if (pageBean.isHasNextPage()) { %> <a href="?page=<%= pageBean.getNextPage() %>&pageSize=<%= pageBean.getPageSize() %>">下一页</a> <% } %> <% if (pageBean.isHasLastPage()) { %> <a href="?page=<%= pageBean.getLastPage() %>&pageSize=<%= pageBean.getPageSize() %>">末页</a> <% } %> <% if (pageBean.getTotalPages() > 1) { %> <select onchange="location.href='?page=<%= pageBean.getCurrentPage() %>&pageSize='+this.options[this.selectedIndex].value"> <option value="5" <%= pageBean.getPageSize() == 5 ? "selected" : "" %>>每页显示5条</option> <option value="10" <%= pageBean.getPageSize() == 10 ? "selected" : "" %>>每页显示10条</option> <option value="20" <%= pageBean.getPageSize() == 20 ? "selected" : "" %>>每页显示20条</option> </select> <% } %> </div>- 在servlet中新增分页的处理代码，具体代码如下：
public class MovieServlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 获取分页信息 int page = Integer.parseInt(request.getParameter("page")); int pageSize = Integer.parseInt(request.getParameter("pageSize")); // 获取电影信息和分页信息 List<Movie> movies = MovieDao.getMoviesByPage(page, pageSize); int totalCount = MovieDao.getTotalCount(); PageBean pageBean = new PageBean(page, pageSize, totalCount); // 将电影信息和分页信息存储到request域中 request.setAttribute("movies", movies); request.setAttribute("pageBean", pageBean); // 转发到jsp页面 request.getRequestDispatcher("/index.jsp").forward(request, response); } }其中分页的处理可以参考以下代码：
public class MovieDao { public static List<Movie> getMoviesByPage(int page, int pageSize) { Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; List<Movie> movies = new ArrayList<Movie>(); try { conn = DBUtil.getConnection(); String sql = "select * from Movie limit ?, ?"; pstmt = conn.prepareStatement(sql); pstmt.setInt(1, (page - 1) * pageSize); pstmt.setInt(2, pageSize); rs = pstmt.executeQuery(); while (rs.next()) { Movie movie = new Movie(); movie.setId(rs.getInt("id")); movie.setName(rs.getString("name")); movie.setType(rs.getString("type")); movie.setActor(rs.getString("actor")); movie.setScore(rs.getDouble("score")); movies.add(movie); } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(rs, pstmt, conn); } return movies; } public static int getTotalCount() { Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; int totalCount = 0; try { conn = DBUtil.getConnection(); String sql = "select count(*) from Movie"; pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if (rs.next()) { totalCount = rs.getInt(1); } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(rs, pstmt, conn); } return totalCount; } }其中PageBean的实现可以参考以下代码：
public class PageBean implements Serializable { private int currentPage; private int pageSize; private int totalCount; private int totalPages; public PageBean(int currentPage, int pageSize, int totalCount) { this.currentPage = currentPage; this.pageSize = pageSize; this.totalCount = totalCount; if (this.totalCount % this.pageSize == 0) { this.totalPages = this.totalCount / this.pageSize; } else { this.totalPages = this.totalCount / this.pageSize + 1; } if (this.currentPage < 1) { this.currentPage = 1; } else if (this.currentPage > this.totalPages) { this.currentPage = this.totalPages; } } public int getPreviousPage() { return this.currentPage - 1; } public int getNextPage() { return this.currentPage + 1; } public int getLastPage() { return this.totalPages; } public int getCurrentPage() { return this.currentPage; } public int getPageSize() { return this.pageSize; } public int getTotalCount() { return this.totalCount; } public int getTotalPages() { return this.totalPages; } public boolean isHasPreviousPage() { return this.currentPage > 1; } public boolean isHasNextPage() { return this.currentPage < this.totalPages; } public boolean isHasFirstPage() { return this.currentPage != 1; } public boolean isHasLastPage() { return this.currentPage != this.totalPages; } }