第九种格调的人生 通过本文主要向大家介绍了javaweb开发详解,javaweb开发详解pdf,javaweb开发技术详解,javaweb运行原理,javaweb原理等相关知识,希望对您有所帮助,也希望大家支持linkedu.com www.linkedu.com
本文实例为大家分享了javaweb分页原理的具体实现代码，供大家参考，具体内容如下
public class Page {
private int currentPage;
private int totalPage;
private int count;
private int PageSize;
private List<Product> list;
private String category;
}
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servlet：
package com.learning.web.servlet;
import java.io.IOException;
import java.util.List;
import javax.enterprise.inject.New;
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 com.learning.domain.Page;
import com.learning.domain.Product;
import com.learning.service.ProductService;
@WebServlet("/showProductByPage")
public class ShowProductByPage extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int currentPage=1;
int pageSize=4;
//第一次取为空
String currentPageString=request.getParameter("currentPage");
if (currentPageString!=null) {
currentPage=Integer.parseInt(currentPageString);
}
String category = request.getParameter("category");
if ("".equals(category)) {
category=null;
}
ProductService productService=new ProductService();
Page page=productService.showProductByPage(currentPage,pageSize,category);
request.setAttribute("page", page);
request.getRequestDispatcher("/product_list.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
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service：
public Page showProductByPage(int currentPage, int pageSize, String category) {
try {
Page page=new Page();
int count=productDao.count(category);
page.setCount(count);
page.setList(productDao.findProductsByPage(currentPage,pageSize,category));
int totalPage=(int) Math.ceil(1.0*count/pageSize);
page.setPageSize(pageSize);
page.setCurrentPage(currentPage);
page.setTotalPage(totalPage);
page.setCategory(category);
return page;
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
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Dao：
public int count(String category) throws SQLException {
QueryRunner queryRunner=new QueryRunner(C3P0Util.getDataSource());
String sql=" select count(*) from products ";
if (category!=null) {
sql+=" where category='"+category+"'";
}
long l= (Long)queryRunner.query(sql, new ScalarHandler(1));
return (int) l;
}
public List<Product> findProductsByPage(int currentPage, int pageSize, String category) throws SQLException {
QueryRunner queryRunner=new QueryRunner(C3P0Util.getDataSource());
String sql=" select * from products ";
if (category!=null) {
sql+=" where category='"+category+"'";
}
sql+=" limit ?,?";
return queryRunner.query(sql, new BeanListHandler<Product>(Product.class),(currentPage-1)*pageSize,pageSize);
}
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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。
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