Servlet类
package com.baidu;
import cn.hutool.core.util.StrUtil;
import javax.servlet.RequestDispatcher;
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.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
@WebServlet("/StudentServlet")
public class StudentServlet extends HttpServlet {
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 模拟从数据库或其他数据源获取学生列表
List<Student> studentList = getStudentList();
// 设置分页参数
int pageSize = 5; // 每页显示的记录数
int currentPage = 1; // 当前页数，默认为第一页
// if (StrUtil.isNotEmpty(request.getAttribute("param1").toString())){
// currentPage = (int) request.getAttribute("param1");
// }
String pageParam = request.getParameter("page");
if (pageParam != null && !pageParam.isEmpty()) {
currentPage = Integer.parseInt(pageParam);
}
// 计算分页的起始索引和结束索引
int startIndex = (currentPage - 1) * pageSize;
int endIndex = Math.min(startIndex + pageSize, studentList.size());
// 获取当前页的学生列表
List<Student> currentPageStudents = studentList.subList(startIndex, endIndex);
//会话request.getSession()
// 将数据存储到request对象中，以便在JSP页面中使用 请求
request.setAttribute("currentPage", currentPage);
request.setAttribute("totalPages", (int) Math.ceil((double) studentList.size() / pageSize));
request.setAttribute("studentList", currentPageStudents);
// 转发到JSP页面
RequestDispatcher dispatcher = request.getRequestDispatcher("index.jsp");
dispatcher.forward(request, response);
}
private List<Student> getStudentList() {
List<Student> studentList = new ArrayList<>();
try (Connection connection = JdcbConnection.requestConnection();
Statement statement = connection.createStatement()){
String sql = "select * from student";
ResultSet resultSet = statement.executeQuery(sql);
while (resultSet.next()){
Student student = new Student(
Integer.parseInt(resultSet.getString("id")),
resultSet.getString("name"),
resultSet.getString("age")
);
studentList.add(student);
}
}catch (Exception e){
e.printStackTrace();
}
// 此处可以连接数据库或其他数据源，这里只是模拟数据
return studentList;
}
}
JSP 代码
<%@ page import="java.util.List" %>
<%@ page import="com.baidu.Student" %>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<meta charset="UTF-8">
<title>分页显示学生列表</title>
</head>
<body>
<h2>学生列表</h2>
<table border="1">
<thead>
<tr>
<th>ID</th>
<th>姓名</th>
<th>年龄</th>
</tr>
</thead>
<tbody>
<%
int currentPage = (int) request.getAttribute("currentPage");
int totalPages = (int) request.getAttribute("totalPages");
List<Student> studentList = (List) request.getAttribute("studentList");
%>
<%
for (int i = 0; i < studentList.size(); i++) {
%>
<tr>
<td><%=studentList.get(i).getId() %></td>
<td><%=studentList.get(i).getName() %></td>
<td><%=studentList.get(i).getAge() %></td>
</tr>
<%
}
%>
<%-- <c:forEach var="student" items="${studentList}">--%>
<%-- <tr>--%>
<%-- <td>${student.id}</td>--%>
<%-- <td>${student.name}</td>--%>
<%-- <td>${student.age}</td>--%>
<%-- </tr>--%>
<%-- </c:forEach>--%>
</tbody>
</table>
<p>
第<%=currentPage %> 页 / 共 <%=totalPages%> 页
<% int shang = currentPage-1;
if (shang ==0 ){
shang=1;
}
int xia = currentPage+1;
if (xia == totalPages+1 ){
xia = totalPages;
}
%>
<a href="/StudentServlet?page=<%=shang%>">上一页</a>
<a href="/StudentServlet?page=<%=xia%>">下一页</a>
<%-- <a href="?page=${currentPage + 1}">下一页</a>--%>
<%-- <c:if test="${currentPage > 1}">--%>
<%-- <a href="?page=${currentPage - 1}">上一页</a>--%>
<%-- </c:if>--%>
<%-- <c:if test="${currentPage < totalPages}">--%>
<%-- --%>
<%-- </c:if>--%>
</p>
</body>
</html>
</body>
</html>
数据库连接
package com.baidu;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class JdcbConnection {
public static Connection requestConnection() throws ClassNotFoundException, SQLException {
//注册驱动
Class.forName("com.mysql.cj.jdbc.Driver");
//获取连接
String url = "jdbc:mysql://127.0.0.1:3306/db2";
String username = "root";
String password = "Lin58936543@";
return DriverManager.getConnection(url,username,password);
}
}
封装实体类
package com.baidu;
public class Student {
private int id ;
private String name;
private String age;
public Student() {
}
public Student(int id, String name, String age) {
this.id = id;
this.name = name;
this.age = age;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", name='" + name + '\'' +
", age='" + age + '\'' +
'}';
}
}