java實現分頁技術詳解
阿新 • • 發佈：2019-02-14
1.編寫通用的分頁工具
public class PageUtil { /*引數需要頁面傳入*/ private Integer pageSize=10;//每頁顯式多少條記錄 private Integer currentPage=1;//當前頁號 /*引數需要從資料查詢*/ private Integer allRowsAmount=0;//總記錄數 private List<?> items;//記錄集合 /*這些引數由計算得出*/ private Integer allPageAmount;//總頁數 private Integer currentPageStartRow=1;//當前頁面的開始行 private Integer currentPageEndRow;//當前頁面的結束行 private Integer firstPage=1;//首頁的頁號 private Integer lastPage;//末頁的頁號 private Integer prevPage;//上一頁頁號 private Integer nextPage;//下一頁頁號 private Integer startPageNum;//導航開始頁號 private Integer endPageNum;//導航結束頁號 private Integer maxPageAmount =10;//最多顯示多少頁 public List<Integer> showPageNums =new ArrayList<Integer>();//要顯示的頁號 public PageUtil() { super(); // TODO Auto-generated constructor stub } /*設定當前頁*/ public void setCurrentPage(int currentPage){ if(currentPage <1){ this.currentPage=1; }else{ this.currentPage=currentPage; } } /*設定每頁記錄數，預設10條*/ public void setPageSize(int pageSize) { this.pageSize = pageSize; } /*設定總記錄數*/ public void setAllRowsAmount(int allRowsAmount) { this.allRowsAmount = allRowsAmount; } /*設定分頁內容*/ public void setItems(List<?> items) { this.items = items; } /*設定導航頁數量*/ public void setMaxPageAmount(int maxPageAmount) { this.maxPageAmount = maxPageAmount; } public void calculatePage(){ //計算總頁數 if(this.allRowsAmount % this.pageSize ==0){ this.allPageAmount=this.allRowsAmount/this.pageSize; }else{ this.allPageAmount=this.allRowsAmount/this.pageSize+1; } //設定首頁 this.firstPage=1; //設定末頁 this.lastPage=this.allPageAmount; if(this.currentPage *pageSize <allRowsAmount){ this.currentPageEndRow =this.currentPage*pageSize; this.currentPageStartRow =(this.currentPage-1)*pageSize+1; }else{ this.currentPageEndRow =this.allRowsAmount; this.currentPageStartRow =(this.allPageAmount-1)*pageSize+1; if(this.currentPageStartRow <0){ this.currentPageStartRow=0; } } //設定前一頁 if(this.currentPage >1){ this.prevPage=this.currentPage-1; }else{ this.prevPage=this.currentPage; } //設定下一頁 if(this.currentPage <this.lastPage){ this.nextPage=this.currentPage+1; }else{ this.nextPage=this.lastPage; } //計算數字導航頁 startPageNum =Math.max(this.currentPage-maxPageAmount/2, firstPage); endPageNum =Math.min(startPageNum+maxPageAmount, lastPage); if(endPageNum-startPageNum <maxPageAmount){ startPageNum =Math.max(endPageNum -maxPageAmount , 1); } for(int i=startPageNum ;i<=endPageNum;i++){ showPageNums.add(i); } } //以下get方法是對外提供的方法用來獲取引數值 public Integer getPageSize() { return pageSize; } public Integer getCurrentPage() { return currentPage; } public Integer getAllRowsAmount() { return allRowsAmount; } public List<?> getItems() { return items; } public Integer getAllPageAmount() { return allPageAmount; } public Integer getCurrentPageStartRow() { return currentPageStartRow; } public Integer getCurrentPageEndRow() { return currentPageEndRow; } public Integer getFirstPage() { return firstPage; } public Integer getLastPage() { return lastPage; } public Integer getPrevPage() { return prevPage; } public Integer getNextPage() { return nextPage; } public Integer getStartPageNum() { return startPageNum; } public Integer getEndPageNum() { return endPageNum; } public Integer getMaxPageAmount() { return maxPageAmount; } public List<Integer> getShowPageNums() { return showPageNums; } @Override public String toString() { return "PageUtil [pageSize=" + pageSize + ", currentPage=" + currentPage + ", allRowsAmount=" + allRowsAmount + ", 每頁內容items=" + items + ", allPageAmount=" + allPageAmount + ", currentPageStartRow=" + currentPageStartRow + ", currentPageEndRow=" + currentPageEndRow + ", firstPage=" + firstPage + ", lastPage=" + lastPage + ", prevPage=" + prevPage + ", nextPage=" + nextPage + ", startPageNum=" + startPageNum + ", endPageNum=" + endPageNum + ", maxPageAmount=" + maxPageAmount + ", 頁號list=" + showPageNums + "]"; } public static void main(String[] args) { List<String> items =new ArrayList<String>(); for(int i=0;i<10;i++){ items.add("str"+i); } PageUtil pageUtil =new PageUtil(); pageUtil.setCurrentPage(1); //pageUtil.setItems(items); pageUtil.setAllRowsAmount(33); pageUtil.calculatePage(); System.out.println(pageUtil); } }
2.servlet+c3p0+mysql實現分頁
工程目錄：
環境搭建：
<dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.2.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.22</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> </dependencies>
c3p0配置檔案：
<c3p0-config> <!-- 預設配置 --> <default-config> <property name="jdbcUrl">jdbc:mysql://localhost:3306/basicjdbc?characterEncoding=utf-8</property> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="user">root</property> <property name="password"></property> <property name="initialPoolSize">3</property> <property name="maxPoolSize">6</property> <property name="maxIdleTime">1000</property> </default-config> <!-- 以下的配置用於個人需要再配置 --> <name-config name="my_config"> <property name="jdbcUrl">jdbc:mysql://localhost:3306/basicjdbc?characterEncoding=utf-8</property> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="user">root</property> <property name="password"></property> <property name="initialPoolSize">3</property> <property name="maxPoolSize">6</property> <property name="maxIdleTime">1000</property> </name-config> </c3p0-config>
使用c3p0連線池的工具類：
public class DbUtil {
private static DataSource dataSource=null;
static{
dataSource=new ComboPooledDataSource();
}
public static Connection getConnection(){
try{
return dataSource.getConnection();
}catch(SQLException e){
throw new RuntimeException(e);
}
}
//釋放物件的連線
public static void close(Connection conn,Statement stmt,ResultSet rs){
if(rs !=null){
try{
rs.close();
}catch(SQLException e){
e.printStackTrace();
throw new RuntimeException(e);
}
}
if(stmt !=null){
try{
stmt.close();
}catch(SQLException e){
e.printStackTrace();
throw new RuntimeException(e);
}
}
if(conn !=null){
try{
conn.close();
}catch(SQLException e){
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void main(String[] args) throws Exception{
String sql="select id,username,gender from myuser limit 3,10";
Connection conn =DbUtil.getConnection();
PreparedStatement ps =conn.prepareStatement(sql);
ResultSet rs =ps.executeQuery();
while(rs.next()){
String id =rs.getString("id");
String username =rs.getString("username");
String gender =rs.getString("gender");
System.out.println(id+","+username+","+gender);
}
DbUtil.close(conn,ps,rs);
}
}
dao層：主要是獲取記錄的總數便於計算其他值，還有就是獲取每頁顯示的資料。
public class UserDaoImpl implements IUserDao{
//從資料庫查詢記錄的總條數
public Integer getAllRowsAmount() throws Exception{
String sql="select count(*) from myuser";
Connection conn =DbUtil.getConnection();
PreparedStatement pstmt =conn.prepareStatement(sql);
ResultSet rs =pstmt.executeQuery();
Integer allRowsAmount=0;
if(rs.next()){
allRowsAmount =rs.getInt("count(*)");
}
DbUtil.close(conn, pstmt, rs);
return allRowsAmount;
}
//通過當前頁號查詢條件記錄
public List<User> getUserByCurrentPage(Integer currentPageStartRow, Integer pageSize) throws Exception{
String sql="select id,username,gender from myuser limit "+(currentPageStartRow-1)+","+pageSize;
Connection conn =DbUtil.getConnection();
PreparedStatement pstmt =conn.prepareStatement(sql);
ResultSet rs =pstmt.executeQuery();
List<User> list =new ArrayList<User>();
while(rs.next()){
User user =new User();
user.setId(rs.getInt("id"));
user.setUsername(rs.getString("username"));
user.setGender(rs.getString("gender"));
list.add(user);
}
DbUtil.close(conn, pstmt, rs);
return list;
}
public static void main(String[] args) throws Exception {
UserDaoImpl userDaoImpl =new UserDaoImpl();
PageUtil pageUtil =new PageUtil();
pageUtil.setAllRowsAmount(userDaoImpl.getAllRowsAmount());
pageUtil.calculatePage();
for(User user :userDaoImpl.getUserByCurrentPage(pageUtil.getStartPageNum(), pageUtil.getPageSize())){
System.out.println(user.getId()+","+user.getUsername()+","+user.getGender());
}
System.out.println(userDaoImpl.getAllRowsAmount());
}
}
public interface IUserDao {
public Integer getAllRowsAmount() throws Exception;
public List<User> getUserByCurrentPage(Integer currentPageStartRow, Integer pageSize) throws Exception;
}model類：
User.java：
public class User {
private int id;
private String username;
private String gender;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
}
public class Page {
private Integer currentPage;
private Integer prevPage;
private Integer nextPage;
private List<User> showUsers =new ArrayList<User>();
private List<Integer> showPageNums =new ArrayList<Integer>();
public Integer getCurrentPage() {
return currentPage;
}
public void setCurrentPage(Integer currentPage) {
this.currentPage = currentPage;
}
public Integer getPrevPage() {
return prevPage;
}
public void setPrevPage(Integer prevPage) {
this.prevPage = prevPage;
}
public Integer getNextPage() {
return nextPage;
}
public void setNextPage(Integer nextPage) {
this.nextPage = nextPage;
}
public List<User> getShowUsers() {
return showUsers;
}
public void setShowUsers(List<User> showUsers) {
this.showUsers = showUsers;
}
public List<Integer> getShowPageNums() {
return showPageNums;
}
public void setShowPageNums(List<Integer> showPageNums) {
this.showPageNums = showPageNums;
}
}
service層：通過頁面傳入當前頁號資料，來查詢需要的值。
UserService.java：
public class UserServiceImpl implements IUserService{
private IUserDao userDao =new UserDaoImpl();
public Page pageUsers(String currentPage) throws Exception{
int allRowsAmount =userDao.getAllRowsAmount();
PageUtil pageUtil =new PageUtil();
pageUtil.setAllRowsAmount(allRowsAmount);
if(currentPage !=null){
pageUtil.setCurrentPage(Integer.parseInt(currentPage));
}
pageUtil.calculatePage();
List<User> list =userDao.getUserByCurrentPage(pageUtil.getCurrentPageStartRow(), pageUtil.getPageSize());
Page page =new Page();
page.setPrevPage(pageUtil.getPrevPage());
page.setNextPage(pageUtil.getNextPage());
page.setShowUsers(list);
page.setShowPageNums(pageUtil.getShowPageNums());
page.setCurrentPage(pageUtil.getCurrentPage());
return page;
}
}
public interface IUserService {
public Page pageUsers(String currentPage) throws Exception;
}Controller層：
public class UserController extends HttpServlet{
/**
*
*/
private static final long serialVersionUID = 1L;
private IUserService userService =new UserServiceImpl();
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String currentPage =req.getParameter("currentPage");
Page page =null;
try {
page =userService.pageUsers(currentPage);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
req.setAttribute("page", page);
req.getRequestDispatcher("/page.jsp").forward(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
super.doPost(req, resp);
}
}
匯入jquery的js檔案：
Page.jsp檔案：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!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=UTF-8">
<script type="text/javascript" src="js/jquery-2.1.3.js"></script>
<script type="text/javascript" src="js/jquery-2.1.3.min.js"></script>
<title>分頁</title>
<style type="text/css">
a{
font-size:14px;
text-decoration:none;
}
td{
text-align:center;
}
#prevPage{
padding:6px;
color:blue;
width:24px;
height:24px;
border:1px solid #ccc;
}
#pageNum{
padding-top:6px;
padding-left:12px;
color:blue;
border:1px solid #ccc;
padding-right:12px;
padding-bottom:6px;
}
#nextPage{
padding:6px;
color:blue;
width:24px;
height:24px;
border:1px solid #ccc;
}
</style>
</head>
<body>
<div class="container" id="pagenation" align="center">
<table border="1" width="80%" cellpadding="5" cellspacing="0">
<tr>
<th>序號</th>
<th>使用者名稱</th>
<th>性別</th>
</tr>
<c:forEach items="${page.showUsers}" var="user">
<tr>
<td>${user.id}</td>
<td>${user.username}</td>
<td>${user.gender}</td>
</tr>
</c:forEach>
</table>
</div>
<div>
<c:when test="${page.currentPage==1}">
<上一頁
</c:when>
<c:otherwise>
<a href="http://localhost:8080/paging/user.htm?currentPage=${page.prevPage}" id="prevPage"><上一頁</a>
</c:otherwise>
<c:forEach items="${page.showPageNums}" var="pageNum">
<a href="http://localhost:8080/paging/user.htm?currentPage=${pageNum}" id="pageNum">${pageNum}</a>
</c:forEach>
<a href="http://localhost:8080/paging/user.htm?currentPage=${page.nextPage}" id="nextPage">下一頁></a>
</div>
</body>
<script type="text/javascript">
$(function(){
$("#prevPage").mousemove(function(){
$("#prevPage").css("border-color","#4a86e8");
$("#prevPage").css("background","#d5dce8");
});
$("#prevPage").mouseout(function(){
$("#prevPage").css("border-color","#ccc");
$("#prevPage").css("background","white");
});
$("#nextPage").mousemove(function(){
$("#nextPage").css("border-color","#4a86e8");
$("#nextPage").css("background","#d5dce8");
});
$("#nextPage").mouseout(function(){
$("#nextPage").css("border-color","#ccc");
$("#nextPage").css("background","white");
});
});
</script>
</html>