条件查询_JSP多条件查询分页

DAO数据访问

package dao;​import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import org.apache.commons.dbutils.QueryRunner;import org.apache.commons.dbutils.handlers.BeanListHandler;import org.apache.commons.dbutils.handlers.ScalarHandler;​import utils.JdbcUtils;import utils.PageBean;import entity.Muli;​public class MuliDao { // 创建QueryRunner对象 private QueryRunner qr = JdbcUtils.getQueryRuner();​  // 查找全部信息列表 public List listMuliAll() { String sql = "SELECT * FROM mulihuji "; try { // 多行数据，封装成对象的集合 List listmuli = qr.query(sql, new BeanListHandler(Muli.class)); return listmuli; } catch (Exception e) { throw new RuntimeException(e); } }  // 分页显示全部数据 public void listMuliAll(PageBean pb,Muli muli) throws SQLException {​ String countsql = "select count(*) from mulihuji where 1=1"; String sql = "select * from mulihuji where 1=1";  List params = new ArrayList(); // 添加查询条件 String xm = muli.getXm(); if (xm != null && xm != "") { countsql += " and xm like ?"; sql += " and xm like ?"; params.add("%" + xm + "%"); } String sfzh = muli.getSfzh(); if (sfzh != null && sfzh != "") { countsql += " and sfzh like ?"; sql += " and sfzh like ?"; params.add("%" + sfzh + "%"); }   //得到总记录数  Long count = qr.query(countsql, new ScalarHandler(),params.toArray()); pb.setTotalCount(count.intValue()); /* * 问题： jsp页面，如果当前页为首页，再点击上一页报错！ 如果当前页为末页，再点下一页显示有问题！ 解决： 1. 如果当前页 <= 0; * 当前页设置当前页为1; 2. 如果当前页 > 最大页数； 当前页设置为最大页数 */ // 判断 if (pb.getCurrentPage() <= 0) { pb.setCurrentPage(1); // 把当前页设置为1 } else if (pb.getCurrentPage() > pb.getTotalPage()) { pb.setCurrentPage(pb.getTotalPage()); // 把当前页设置为最大页数 }​ // 1. 获取当前页： 计算查询的起始行、返回的行数 int currentPage = pb.getCurrentPage(); int index = (currentPage - 1) * pb.getPageCount(); // 查询的起始行 int pagecount = pb.getPageCount(); // 每页的行数   sql += " limit ?,?"; params.add(index); params.add(pagecount);  List pageData = qr.query(sql, new BeanListHandler(Muli.class),params.toArray() ); //获取一页的数据 // 设置到pb对象中 pb.setPageData(pageData); ​ }​ }​

Servlet设计

package servlet;​import java.io.IOException;import java.sql.SQLException;​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 dao.MuliDao;import entity.Muli;import utils.PageBean;​/** * Servlet implementation class QueryListMuliServlet */@WebServlet("/querymuli")public class QueryListMuliServlet extends HttpServlet { private static final long serialVersionUID = 1L;​ /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); String xm = request.getParameter("xm"); String sfzh = request.getParameter("sfzh"); //实例化实体类并赋值  Muli muli=new Muli(); muli.setXm(xm); muli.setSfzh(sfzh);  //1. 获取“当前页”参数； (第一次访问当前页为null)  String currPage = request.getParameter("currentPage"); // 判断 if (currPage == null || "".equals(currPage.trim())){ currPage = "1"; // 若第一次访问，设置当前页为1; } // 转换为整数型 int currentPage = Integer.parseInt(currPage); //实例化pageben类 PageBean pb = new PageBean(); pb.setCurrentPage(currentPage);  try { //调用数据访问的方法，传递两个参数 MuliDao mulidao = new MuliDao(); mulidao.listMuliAll(pb,muli);  request.setAttribute("pageBean