首先后台分页需要理清分页思路，把数据库里面需要分页的信息放到List集合中，然后按照页面反馈给后台的页码对List集合进行SubList切割把切完的List传到前端进行显示。
1.分页的demo文件结构图
导入的包
2.代码
SplitPageServlet代码
package ActionServlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
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 Bean.ProjectBean;
import Service.SplitPage;
/** * Servlet implementation class SplitPageServlet */@WebServlet("/SplitPageServlet")public class SplitPageServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/** * @see HttpServlet#HttpServlet() */ public SplitPageServlet() {
super();
// TODO Auto-generated constructor stub }
/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub List<ProjectBean>listArr = new ArrayList<ProjectBean>();
String currrentPageString = request.getParameter("currrentPage");
String numberForSplitPage = request.getParameter("numberForSplitPage");
if( currrentPageString ==null){
currrentPageString = "1";
}
if( numberForSplitPage == null){
numberForSplitPage = "5";
}
SplitPage splitPage = new SplitPage();
try {
listArr = splitPage.AllSplitPage(numberForSplitPage, currrentPageString);
request.setAttribute("subResult", listArr);
}
catch (ClassNotFoundException | SQLException e) {
// TODO Auto-generated catch block e.printStackTrace();
}
System.out.println(SplitPage.pageNumber);
System.out.println(SplitPage.currentPageIndex);
request.setAttribute("pageNumber", SplitPage.pageNumber);
request.setAttribute("currentPageIndex", SplitPage.currentPageIndex);
request.getRequestDispatcher("/servlet/ShowViewIndex").forward(request, response);
}
/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub doGet(request, response);
}
}
ProjectBean代码
package Bean;
public class ProjectBean {
private String projectId = null;
private String projectName = null;
private String projectType = null;
private String userNo = null;
private String projectUser = null;
public String getProjectId(){
if(projectId==null){
projectId ="";
}
return this.projectId;
}
public void setProjectId(String projectId){
this.projectId = projectId;
}
public void setProjectName(String projectName){
this.projectName = projectName;
}
public String getProjectName(){
return this.projectName;
}
public void setType(String projectType){
this.projectType = projectType;
}
public String getProjectType(){
return this.projectType;
}
public void setUserNo(String userNo){
this.userNo = userNo;
}
public String getUserNo(){
return this.userNo;
}
public void setProjectUser(String projectUser){
this.projectUser = projectUser;
}
public String getProjectUser(){
return this.projectUser;
}
}
SplitPageBean 代码
package Bean;
public class SplitPageBean {
private int allitems;
//总的记录数 private int currentRecord;
//当前的记录数 private int lastPageRecord ;
//上一页记录数开始数 private int nextPageRecord;
//下一页记录数开始数 private int lastPageIndex ;
//上一页 private int nextPageIndex;
//下一页 private int currentPageIndex;
//当前页 private int numberForSplitPage;
//每页分的数量 private int allPageNumber;
public int getAllitems(){
return this.allitems;
}
public void setAllitems(int allitems){
this.allitems = allitems;
}
public int getCurrentRecord(){
return this.currentRecord;
}
public void setCurrentRecord(int currentPageIndex){
this.currentRecord = currentPageIndex * this.numberForSplitPage;
}
public int getlastPageRecord(){
return this.lastPageRecord;
}
public void setLastPageRecord(int lastPageIndex){
this.lastPageRecord = lastPageIndex * this.numberForSplitPage;
}
public int getNextPageRecord(){
return this.nextPageRecord;
}
public void setNextPageRecord(int nextPageIndex){
this.nextPageRecord = nextPageIndex * this.numberForSplitPage;
}
public int getLastPageIndex(){
return this.lastPageIndex;
}
public void setLastPageIndex(int currentPageIndex){
this.lastPageIndex = currentPageIndex - 1;
}
public int getNextPageIndex(){
return this.nextPageIndex;
}
public void setNextPageIndex(int currentPageIndex){
this.nextPageIndex = currentPageIndex - 1;
}
public int getCurrentPageIndex(){
return this.currentPageIndex;
}
public void setCurrentPageIndex(int currentPageIndex){
this.currentPageIndex = currentPageIndex;
}
public int getNumberForSplitPage(){
return this.numberForSplitPage;
}
public void setNumberForSplitPage(int numberForSplitPage){
this.numberForSplitPage = numberForSplitPage;
}
public int getAllPageNumber(){
return this.allPageNumber;
}
public void setAllPageNumber(int allitems){
this.allPageNumber = allitems / this.numberForSplitPage + 1;
}
}
QueryProject代码
package Dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import Bean.ProjectBean;
import Service.ConnectDataBase;
public class QueryProject {
private List<ProjectBean> listArr = new ArrayList();
public List<ProjectBean> QueryAllProject() throws ClassNotFoundException, SQLException{
Connection conn=null;
Statement stat=null;
ResultSet rs=null;
ConnectDataBase connectDataBase =new ConnectDataBase();
conn = connectDataBase.connect();
stat = conn.createStatement();
rs = stat.executeQuery("select*from project");
while(rs.next()){
ProjectBean projectBean = new ProjectBean();
projectBean.setProjectId(rs.getString("projectId"));
projectBean.setProjectName(rs.getString("projectName"));
projectBean.setType(rs.getString("projectType"));
projectBean.setUserNo(rs.getString("UserNo"));
projectBean.setProjectUser(rs.getString("projectUser"));
listArr.add(projectBean);
}
connectDataBase.close(stat, conn);
return listArr;
}
// public static void main(String[] args) throws ClassNotFoundException, SQLException{
// List<ProjectBean> listArr = new ArrayList();
// QueryProject queryProject = new QueryProject();
// listArr = queryProject.QueryAllProject();
// ProjectBean projectBean = new ProjectBean();
// projectBean = listArr.get(0);
// System.out.println(projectBean.getProjectId());
// projectBean = listArr.get(2);
// System.out.println(projectBean.getProjectId());
// System.out.println(listArr.size());
// }
}
ConenctDataBase代码
package Service;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class ConnectDataBase {
private String url = "jdbc:MySQL://localhost:3306/zhongchuangweb";
private String user = "root";
private String password = "12345";
public Connection connect() throws ClassNotFoundException, SQLException{
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(url,user,password);
return conn;
}
//关闭数据库资源 public void close(Statement stat,Connection conn) throws SQLException{
if(stat!=null){
stat.close();
}
if(conn!=null){
conn.close();
}
}
}
SplitPage代码
package Service;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import Bean.ProjectBean;
import Bean.SplitPageBean;
import Dao.QueryProject;
public class SplitPage {
public static int pageNumber;
public static int currentPageIndex;
private List<ProjectBean> splitArr = new ArrayList();
{
QueryProject queryProject = new QueryProject();
try {
splitArr = queryProject.QueryAllProject();
}
catch (ClassNotFoundException | SQLException e) {
// TODO Auto-generated catch block e.printStackTrace();
}
}
public List<ProjectBean> AllSplitPage(String numberForSplitPage,String requestPageIndex) throws ClassNotFoundException, SQLException{
List<ProjectBean> result = new ArrayList<ProjectBean>();
int numberForSplitPageInt = Integer.parseInt(numberForSplitPage);
//每页的数量 int requestPageIndexInt = Integer.parseInt(requestPageIndex);
//请求的页码 SplitPageBean splitPageBean = new SplitPageBean();
splitPageBean.setAllitems(splitArr.size());
//设置总的记录数 splitPageBean.setNumberForSplitPage(numberForSplitPageInt);
//设置每页的记录数量 splitPageBean.setAllPageNumber(splitArr.size());
pageNumber = splitPageBean.getAllPageNumber();
splitPageBean.setCurrentPageIndex(requestPageIndexInt);
//设置请求页页码 currentPageIndex = splitPageBean.getCurrentPageIndex();
splitPageBean.setLastPageRecord(requestPageIndexInt-1);
if(splitPageBean.getAllitems()<splitPageBean.getNumberForSplitPage()){
result = splitArr;
}
else if(splitPageBean.getCurrentPageIndex()*splitPageBean.getNumberForSplitPage() > splitPageBean.getAllitems()){
result = splitArr.subList(splitPageBean.getlastPageRecord(),splitPageBean.getAllitems());
}
else{
result = splitArr.subList(splitPageBean.getlastPageRecord(),splitPageBean.getlastPageRecord()+splitPageBean.getNumberForSplitPage());
//SubList用法不包含末尾索引 }
return result;
}
// public static void main(String[] args) throws ClassNotFoundException, SQLException{
// List<ProjectBean> TestResult = new ArrayList<ProjectBean>();
// ProjectBean projectBean = new ProjectBean();
// SplitPage splitPage = new SplitPage();
// TestResult = splitPage.AllSplitPage("5","1");
// projectBean = TestResult.get(0);
// System.out.println(projectBean.getProjectId());
// projectBean = TestResult.get(1);
// System.out.println(projectBean.getProjectId());
// projectBean = TestResult.get(2);
// System.out.println(projectBean.getProjectId());
// projectBean = TestResult.get(3);
// System.out.println(projectBean.getProjectId());
// projectBean = TestResult.get(4);
// System.out.println(projectBean.getProjectId());
// projectBean = TestResult.get(5);
// System.out.println(projectBean.getProjectId());
// // }
}
显示层
ShowViewIndex代码
package View;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/** * Servlet implementation class ShowViewIndex */@WebServlet("/ShowViewIndex")public class ShowViewIndex extends HttpServlet {
private static final long serialVersionUID = 1L;
/** * @see HttpServlet#HttpServlet() */ public ShowViewIndex() {
super();
// TODO Auto-generated constructor stub }
/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub request.getRequestDispatcher("/NewFile.jsp").forward(request, response);
}
/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub doGet(request, response);
}
}
jsp页面代码
<%@ 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 PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1"><title>数据库内容分页显示</title><style type="text/css">*{
margin:0;
padding:0;
}
ul li{
width:50px;
height:24px;
line-height:24px;
float:left;
margin-left:0px;
display:inline;
margin-top:5px;
overflow:hidden;
}
ul li button{
width:50px;
height:24px;
margin:0px;
padding:0px;
}
</style></head><body> <table> <thead> <tr> <th style="text-align:center;
">编号</th> <th style="text-align:center;
">名称</th> <th style="text-align:center;
">类型</th> <th style="text-align:center;
">学号</th> <th style="text-align:center;
">负责人</th> </tr> </thead> <tbody> <c:forEach var="project" items="${
subResult}
"> <tr> <td><c:out value="${
project.projectId}
"></c:out></td> <td><c:out value="${
project.projectName}
"></c:out></td> <td><c:out value="${
project.projectType}
"></c:out></td> <td><c:out value="${
project.userNo}
"></c:out></td> <td><c:out value="${
project.projectUser}
"></c:out></td> </tr> </c:forEach> </tbody> </table> <div align = "center"> <ul> <c:choose> <c:when test="${
currentPageIndex>1}
"> <li><a href="${
pageContext.request.contextPath}
/servlet/SplitPageServlet?currrentPage=${
currentPageIndex-1}
"><button><</button></a></li> </c:when> <c:otherwise> <li><a><button><</button></a></li> </c:otherwise> </c:choose> <% int i =(Integer)request.getAttribute("pageNumber");
for (int j=0;
j<i;
j++) {
%> <li><a href="${
pageContext.request.contextPath}
/servlet/SplitPageServlet?currrentPage=<%=j+1%>"><button><%=j+1%></button></a></li> <%}
%> <c:choose> <c:when test="${
currentPageIndex+1<=pageNumber}
"> <li><a href="${
pageContext.request.contextPath}
/servlet/SplitPageServlet?currrentPage=${
currentPageIndex+1}
"><button>></button></a></li> </c:when> <c:otherwise> <li><a><button>></button></a></li> </c:otherwise> </c:choose> </ul> </div> </body></html>
xml代码
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <display-name></display-name> <welcome-file-list> <welcome-file>SplitPageServlet</welcome-file> </welcome-file-list> <servlet> <servlet-name>ShowViewIndex</servlet-name> <servlet-class>View.ShowViewIndex</servlet-class> </servlet> <servlet-mapping> <servlet-name>ShowViewIndex</servlet-name> <url-pattern>/servlet/ShowViewIndex</url-pattern> </servlet-mapping> <servlet> <servlet-name>SplitPageServlet</servlet-name> <servlet-class>ActionServlet.SplitPageServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>SplitPageServlet</servlet-name> <url-pattern>/servlet/SplitPageServlet</url-pattern> </servlet-mapping></web-app>
运行结果展示
数据库describe
同时在本次demo中认识到了xml的中使用欢迎界面通过 <welcome-file-list> <welcome-file>静态界面（jsp html）</welcome-file> </welcome-file-list>还可以使用servlet直接用servlet名即可。
初学java和javaee 写一点自己做的东西，代码写的不是很规范，不喜勿喷。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
