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>编号</th> <th>名称</th> <th>类型</th> <th>学号</th> <th>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
<"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查字典教程网。
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