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功能实现
老师角色查看所有学生
获取学生列表和分页
1.修改index.jsp
不能直接跳stuList.jsp，没数据
<%if("teacher".equals(role)){%> <a href="TeaInitModifyServlet?username=<%=username%>">修改信息</a> <a href="GetStuListServlet?curPage=1">查看所有学生</a> <%}%> 2.新增GetStuListServlet
拿数据和分页
@WebServlet("/GetStuListServlet") public class GetStuListServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); //获取当前页数 int curPage = Integer.parseInt(request.getParameter("curPage")); //设置当前页的数据条数 int count = 15; //计算偏移量 int offset = (curPage-1)*count; //计算总页数 int totalPage; try { int allCount = DBUtils.getAllCount("student"); if(allCount % count == 0){ totalPage = allCount/count; }else{ totalPage = allCount/count + 1; } } catch (SQLException e) { throw new RuntimeException(e); } //从数据库获取学生的集合 List<Student> students = null; try { students = DBUtils.commonQueryList(Student.class, "select * from student limit ?,?", offset, count); } catch (SQLException e) { throw new RuntimeException(e); } //处理学生集合 List<StudentDto> studentDtos = DtoUtils.studentDtoListHandler(students); //将数据存入到请求对象中 request.setAttribute("curPage",curPage); request.setAttribute("totalPage",totalPage); request.setAttribute("studentDtos",studentDtos); //request.setAttribute("students",students);直接传 //跳转 request.getRequestDispatcher("stuList.jsp").forward(request,response); } } 修改DBUtils–分页
新增getAllCount()
/** * 获取当前表的总条数 */ public static int getAllCount(String table) throws SQLException { Connection connection = getConnection(); String sql = "select count(1) from " + table; PreparedStatement statement = connection.prepareStatement(sql); ResultSet resultSet = statement.executeQuery(); if(resultSet.next()){ int allCount = resultSet.getInt(1); return allCount; } return 0; } 修改Student–分页
做假数据，在实体类里面可以写main方法，插入操作
//做分页的假数据 public static void main(String[] args) { for (int i = 1; i < 100; i++) { String username = "xiaohei" + i; String password = "123123"; String name = "小黑" + i; String sex = "man"; int age = 23; String[] hobbies = {"football","basketball"}; try { DBUtils.commonUpdate("insert into student(username,password,name,sex,age,hobbies) values(?,?,?,?,?,?)",username,password,name,sex,age, StringUtils.handleArray(hobbies)); } catch (SQLException e) { throw new RuntimeException(e); } } } 新增StudentDto–处理学生信息
分包新增信息处理类，以方便工具类对学生的信息处理
package com.ckl.dto; import com.ckl.pojo.Student; public class StudentDto { private Student student; private String sex; private String hobbies; //自动生成方法略 } 新增DtoUtils --处理学生信息
工具类，处理学生信息提升页面展示效果
public class DtoUtils { public static StudentDto studentDtoHandler(Student student){ //处理学生的性别数据 String sex = student.getSex(); if("man".equals(sex)){ sex = "男"; }else if("woman".equals(sex)){ sex = "女"; } //处理学生的爱好数据 String hobbies = student.getHobbies(); hobbies = hobbies.replaceAll("football","足球"); hobbies = hobbies.replaceAll("basketball","篮球"); hobbies = hobbies.replaceAll("shop","购物"); //创建StudentDto StudentDto studentDto = new StudentDto(student, sex, hobbies); return studentDto; } public static List<StudentDto> studentDtoListHandler(List<Student> students){ List<StudentDto> studentDtos = new ArrayList<>(); for (Student student : students) { StudentDto studentDto = studentDtoHandler(student); studentDtos.add(studentDto); } return studentDtos; } } 3.stuList.jsp
直接获取数据库的学生数据
//未处理 List<Student> students = (List<Student>) request.getAttribute("students"); <%for(Student student:students){%> <th><%=student.getUsername()%></th> <th><%=student.getName()%></th> <th><%=student.getSex()%></th> <th><%=student.getAge()%></th> <th><%=student.getHobbies()%></th> 添加学生信息处理后获取
//处理后 <%@ page import="java.util.List" %> <%@ page import="com.qf.pojo.Student" %> <%@ page import="com.qf.dto.StudentDto" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <% List<StudentDto> studentDtos = (List<StudentDto>) request.getAttribute("studentDtos"); int curPage = (int) request.getAttribute("curPage"); int totalPage = (int) request.getAttribute("totalPage"); %> <button οnclick="goIndex()">返回</button> <h1>学生列表页面</h1> <table border="1" width="500px"> <tr> <th>账号</th> <th>姓名</th> <th>性别</th> <th>年龄</th> <th>爱好</th> <th>操作</th> </tr> //获取学生信息展示 <%for(StudentDto studentDto:studentDtos){%> <tr> <th><%=studentDto.getStudent().getUsername()%></th> <th><%=studentDto.getStudent().getName()%></th> <th><%=studentDto.getSex()%></th> <th><%=studentDto.getStudent().getAge()%></th> <th><%=studentDto.getHobbies()%></th> <th> <a href="#">修改</a> <a href="#">删除</a> </th> </tr> <%}%> </table> //分页 <a href="GetStuListServlet?curPage=1">首页</a> <%if(curPage > 1){%> <a href="GetStuListServlet?curPage=<%=curPage-1%>">上一页</a> <%}%> <%if(curPage < totalPage){%> <a href="GetStuListServlet?curPage=<%=curPage+1%>">下一页</a> <%}%> <a href="GetStuListServlet?curPage=<%=totalPage%>">尾页</a> <script type="text/javascript"> function goIndex(){ window.location = "index.jsp"; } </script> </body> </html> 老师角色修改和删除学生信息
修改
修改stuList.jsp
<%for(StudentDto studentDto:studentDtos){%> <tr> <th> <a href="StuInitModifyServlet?username=<%=studentDto.getStudent().getUsername()%>">修改</a> <a href="StuDeleteServlet?username=<%=studentDto.getStudent().getUsername()%>">删除</a> </th> </tr> <%}%> 修改StuModifyServlet
获取角色
通过角色判断修改
学生需要更新Session、Cookie里的数据，跳转详情页面
老师跳转GetStuListServlet，需要更新数据【因为修改了需要刷新页面】
// request.setAttribute("name",name); // response.addCookie(CookieUtils.createCookie("name",name,60*60*24*5)); // // response.sendRedirect("index.jsp"); String role = (String) request.getSession().getAttribute("role"); if("student".equals(role)){ //更新Session里的数据 request.getSession().setAttribute("name",name); //更新Cookie里的数据 response.addCookie(CookieUtils.createCookie("name",name,60*60*24*5)); //跳转详情页面 response.sendRedirect("index.jsp"); }else if("teacher".equals(role)){ //跳转 response.sendRedirect("GetStuListServlet?curPage=1"); } 删除
新增StuDeleteServlet
设置编码格式，获取请求中的账号，通过学生账号删除学生，最后跳转GetStuListServlet同时更新数据
注意：实际开发项目中是不会直接用delete，而是改状态，数据库有提到
@WebServlet("/StuDeleteServlet") public class StuDeleteServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); String username = request.getParameter("username"); try { DBUtils.commonUpdate("delete from student where username=?",username); } catch (SQLException e) { throw new RuntimeException(e); } //跳转 response.sendRedirect("GetStuListServlet?curPage=1"); } } 