package com.app.pagination;
import java.util.List;
/**
 * 通用分页接口
 * @author: super.wwz@hotmail.com
 * @ClassName: Pagination
 * @Version: v0.1
 * @param <T>
 */ 
public interface Pagination<T> {
 /**
 * 判断是否是首页
 * @return
 */
 boolean isFirst();
 /**
 * 判断是否是尾页
 * @return
 */
 boolean isLast();
 /**
 * 判断是否有上一页
 * @return
 */
 boolean isPrevious();
 /**
 * 判断是否有下一页
 * @return
 */
 boolean isNext();
 
 
 /**
 * 获取上一页的页码
 * @return
 */
 int getPreviousIndex();
 /**
 * 获取下一页的页码
 * @return
 */
 int getNextIndex();
 /**
 * 获取当前页码
 * @return
 */
 int getPageIndex();
 /**
 * 获取当前页大小
 * @return
 */
 int getPageSize();
 /**
 * 获取总页数
 * @return
 */
 int getTotalPages();
 /**
 * 获取数据总行数
 * @return
 */
 int getTotalElements();
 
 /**
 * 获取当前页的数据
 * @return
 */
 List<T> getCurrData();
 
 /**
 * 获取数字分页链接对象
 * @return
 */
 BetweenIndex getBetweenIndex();
 
 /**
 * 获取每页显示的分页链接数
 * @return
 */
 int getPageLinkNumber();
 
 /**
 * 设置每页的分页链接数量
 * @param pageLinkNumber
 */
 void setPageLinkNumber(int pageLinkNumber);
}

package com.app.pagination;
/**
 * 开始链接-结束链接
 * @author: super.wwz@hotmail.com
 * @ClassName: BetweenIndex
 * @Version: v0.1
 */
public interface BetweenIndex {
 /**
 * 获取开始分页链接索引
 * @return
 */
 int getBeginIndex();
 /**
 * 获取结束分页链接索引
 * @return
 */
 int getEndIndex();
}

package com.app.pagination.impl;
import java.util.List;
import com.app.pagination.BetweenIndex;
import com.app.pagination.Pagination;
/**
 * Pagination接口默认实现
 * @author: super.wwz@hotmail.com
 * @ClassName: DefaultPagination
 * @Version: v0.1
 * @param <T>
 */
public class DefaultPagination<T> implements Pagination<T> {
 private int totalElements;
 private int pageSize;
 private int totalPages;
 private int pageIndex;
 private QueryHandler<T> queryHandler;
 private List<T> currData;
 private int pageLinkNumber;
 public DefaultPagination(int pageIndex, int pageSize, QueryHandler<T> queryHandler, int pageLinkNumber) {
 this(pageIndex, pageSize, queryHandler);
 setPageLinkNumber(pageLinkNumber);
 }
 public DefaultPagination(int pageIndex, int pageSize, QueryHandler<T> queryHandler){
 //初始化数据访问回调接口
 this.queryHandler = queryHandler;
 //查询总行数
 setTotalElements();
 //修正页大小
 setPageSize(pageSize);
 //计算总页数:
 setTotalPages();
 //修正页码
 setPageIndex(pageIndex);
 //查询当前页数据
 setCurrData();
 }
 private void setCurrData() {
 // TODO Auto-generated method stub
 this.currData = queryHandler.getCurrData(pageIndex, pageSize);
 }
 private void setPageIndex(int pageIndex) {
 // TODO Auto-generated method stub
 if(pageIndex < 1) {
 this.pageIndex = 1;
 } else if(pageIndex > totalPages) {
 this.pageIndex = totalPages;
 } else {
 this.pageIndex = pageIndex;
 }
 }
 private void setTotalPages() {
 // TODO Auto-generated method stub
 if(pageSize > 0) {
 /*//普通算法:
 this.totalPages = totalElements % pageSize == 0 "htmlcode">

package com.app.pagination.impl;
import java.util.List;
/**
 * 分页查询回调接口
 * @author: super.wwz@hotmail.com
 * @ClassName: QueryHandler
 * @Version: v0.1
 * @param <T>
 */
public interface QueryHandler<T> {
 /**
 * 获取数据总行数
 * @return
 */
 int getTotalElements();
 
 /**
 * 获取当前页的数据
 * @param pageIndex
 * @param pageSize
 * @return
 */
 List<T> getCurrData(int pageIndex, int pageSize);
}



BookDaoImpl
BookDao的实现类(BookDao接口已经省略)


package com.app.dao.impl;
import java.sql.SQLException;
import java.util.List;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import com.app.bean.Book;
import com.app.dao.BaseDao;
import com.app.dao.BookDao;
public class BookDaoImpl extends BaseDao implements BookDao {
 @Override
 public int count() {
 // 查询数据总行数
 String sql = "select count(1) from t_book";
 try {
 return getQueryRunner().query(sql, new ScalarHandler<Integer>());
 } catch (SQLException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 return 0;
 }
 @Override
 public List<Book> getBooks(int pageIndex, int pageSize) {
 // 关于SQLServer的查询分页sql
 StringBuffer sql = new StringBuffer();
 sql.append("select * from (");
 sql.append(" select row_number() over(order by(id)) new_id,* from t_book");
 sql.append(") t where new_id between ");
 try {
 return getQueryRunner().query(sql.toString(),
  new BeanListHandler<Book>(Book.class),
  pageSize * (pageIndex - 1) + 1,pageSize * pageIndex);
 } catch (SQLException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 return null;
 }
}



BookServiceImpl
BookService业务逻辑接口的实现类 (BookService已经省略)


package com.app.service.impl;
import java.util.List;
import com.app.bean.Book;
import com.app.dao.BookDao;
import com.app.dao.impl.BookDaoImpl;
import com.app.pagination.Pagination;
import com.app.pagination.impl.DefaultPagination;
import com.app.pagination.impl.QueryHandler;
import com.app.service.BookService;
/**
 * 业务逻辑层查询分页数据示例
 * @author: super.wwz@hotmail.com
 * @ClassName: BookServiceImpl
 * @Version: v0.1
 */
public class BookServiceImpl implements BookService {
 private BookDao bookDao = new BookDaoImpl();
 @Override
 public Pagination<Book> getBookList(int pageIndex, int pageSize,int pageLinkNumber) {
 // TODO Auto-generated method stub
 return new DefaultPagination<Book>(pageIndex, pageSize, new QueryHandler<Book>() {
 @Override
 public int getTotalElements() {
 // TODO Auto-generated method stub
 return bookDao.count();
 }
 @Override
 public List<Book> getCurrData(int pageIndex, int pageSize) {
 // TODO Auto-generated method stub
 return bookDao.getBooks(pageIndex, pageSize);
 }
 },pageLinkNumber);
 }
}



BookAction
有关图书的Servlet控制器


package com.app.web.action;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.app.bean.Book;
import com.app.pagination.Pagination;
import com.app.service.BookService;
import com.app.service.impl.BookServiceImpl;
public class BookAction extends HttpServlet {
 private static final long serialVersionUID = 5275929408058702210L;
 private BookService bookService = new BookServiceImpl();
 @Override
 protected void service(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
 request.setCharacterEncoding("UTF-8");
 response.setCharacterEncoding("UTF-8");
 int pageIndex = 1;
 int pageSize = 10;
 try {
 pageIndex = Integer.parseInt(request.getParameter("pageIndex"));
 pageSize = Integer.parseInt(request.getParameter("pageSize"));
 } catch (NumberFormatException e) {
 e.printStackTrace();
 }
 //6: 显示的分页链接个数
 Pagination<Book> bookPagination = bookService.getBookList(pageIndex, pageSize,6);
 request.setAttribute("bookPagination", bookPagination);
 request.getRequestDispatcher("index.jsp").forward(request, response);
 }
}



Jsp
index.jsp

将Pagiation应用到bootstrap上的简单示例bootstrap版本: 3.3.5


<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<c:if test="${requestScope.bookPagination == null }">
 <c:redirect url="bookAction"></c:redirect>
</c:if>
<!DOCTYPE html">
<html>
 <head>
 <title>图书信息列表</title>
 <!-- Bootstrap v3.3.5 -->
<link href="${pageContext.request.contextPath}/bootstrap-3.3.5-dist/css/bootstrap.min.css"
 type="text/css" rel="stylesheet" charset="utf-8" />
<link id="bootstrapTheme"
 href="${pageContext.request.contextPath}/bootstrap-3.3.5-dist/css/bootstrap-theme.min.css"
 type="text/css" rel="stylesheet" charset="utf-8" />
<script src="/UploadFiles/2021-04-02/jquery.min.js">

实例数据
说明:



  
如果需要扩展分页功能, 请扩展Pagiation接口以及其余实现类;
  
此外, 此分页不依赖任何数据库(重新实现QueryHandler查询回调接口即可), 可适用于任何web项目中;

  

使用List 集合模拟数据库的使用示例:



package com.app.service.impl;
import java.util.ArrayList;
import java.util.List;
import com.app.bean.Book;
import com.app.pagination.Pagination;
import com.app.pagination.impl.DefaultPagination;
import com.app.service.BookService;
/**
 * 使用List<T>集合模拟数据库
 * @author: super.wwz@hotmail.com
 * @ClassName: BookServiceImpl2
 * @Version: v0.1
 */
public class BookServiceImpl2 implements BookService {
// private BookDao bookDao = new BookDaoImpl();
 private static List<Book> list = new ArrayList<Book>();
 //初始化List<Book>数据
 static {
 list.add(new Book(1, "书名1", 18));
 list.add(new Book(2, "书名2", 13));
 list.add(new Book(3, "书名3", 18));
 list.add(new Book(4, "书名4", 38));
 list.add(new Book(5, "书名5", 18));
 list.add(new Book(6, "书名6", 58));
 list.add(new Book(7, "书名7", 12));
 list.add(new Book(8, "书名8", 11));
 list.add(new Book(9, "书名9", 13));
 list.add(new Book(10, "书名10", 22));
 list.add(new Book(11, "书名11", 19));
 list.add(new Book(12, "书名12", 13));
 list.add(new Book(13, "书名13", 19));
 list.add(new Book(14, "书名14", 32));
 }
 @Override
 public Pagination<Book> getBookList(int pageIndex, int pageSize, int pageLinkNumber) {
 return new DefaultPagination<Book>(pageIndex, pageSize, new QueryHandler<Book>() {
 @Override
 public int getTotalElements() {
  //return bookDao.count();
 return list.size();
 }
 @Override
 public List<Book> getCurrData(int pageIndex, int pageSize) {
  //return bookDao.list(pageIndex, pageSize);
 int fromIndex = (pageIndex - 1) * pageSize;
 int endIndex = fromIndex + pageSize;
 endIndex = endIndex > list.size() ? list.size() : endIndex;
 return list.subList(fromIndex, endIndex);
 }
 }, pageLinkNumber);
 }
}




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