JAVA分页原理（二）——使用SQL实现
JdbcSqlStudentDaoImpl.java
package com.imooc.page.dao;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.imooc.page.Constant;
import com.imooc.page.model.Pager;
import com.imooc.page.model.Student;
import com.imooc.page.util.JdbcUtil;
/**
* 使用mysql数据库limit关键字实现分页
* @author yrui
*
*/
public class JdbcSqlStudentDaoImpl implements StudentDao {
@Override
public Pager findStudent(Student searchModel, int pageNum, int pageSize) {
Pager result = null;
//存放查询参数
List JdbcSqlStudentServiceImpl.java
package com.imooc.page.service;
import com.imooc.page.dao.JdbcSqlStudentDaoImpl;
import com.imooc.page.dao.StudentDao;
import com.imooc.page.model.Pager;
import com.imooc.page.model.Student;
public class JdbcSqlStudentServiceImpl implements StudentService {
private StudentDao studentDao;
public JdbcSqlStudentServiceImpl(){
//创建service实现类时，初始化dao对象
studentDao = new JdbcSqlStudentDaoImpl();
}
@Override
public Pager findStudent(Student searchModel, int pageNum, int pageSize) {
Pager result = studentDao.findStudent(searchModel, pageNum, pageSize);
return result;
}
public StudentDao getStudentDao() {
return studentDao;
}
public void setStudentDao(StudentDao studentDao) {
this.studentDao = studentDao;
}
}
JdbcSqlServlet.java
package com.imooc.page.servlet;
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.imooc.page.Constant;
import com.imooc.page.model.Pager;
import com.imooc.page.model.Student;
import com.imooc.page.service.JdbcSqlStudentServiceImpl;
import com.imooc.page.service.StudentService;
import com.imooc.page.util.StringUtil;
public class JdbcSqlServlet extends HttpServlet {
private static final long serialVersionUID = -4873699362194465829L;
private StudentService studentService = new JdbcSqlStudentServiceImpl();
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
//接收request里的参数
String stuName = request.getParameter("stuName");
int gender = Constant.DEFAULT_GENDER;
String genderStr = request.getParameter("gender");
if(genderStr!=null&&!"".equals(genderStr.trim())){
gender = Integer.parseInt(genderStr);
}
//校验pageNum参数输入的合法性
String pageNumStr = request.getParameter("pageNum");
if(pageNumStr!=null&&!StringUtil.isNum(pageNumStr)){
request.setAttribute("errorMsg", "参数传输错误");
request.getRequestDispatcher("jdbcSqlStudent.jsp").forward(request, response);
return;
}
int pageNum = Constant.DEFAULT_PAGE_NUM;
if(pageNumStr!=null&&!"".equals(pageNumStr.trim())){
pageNum = Integer.parseInt(pageNumStr);
}
int pageSize = Constant.DEFAULT_PAGE_SIZE;
String pageSizeStr = request.getParameter("pageSize");
if(pageSizeStr!=null&&!"".equals(pageSizeStr.trim())){
pageSize = Integer.parseInt(pageSizeStr);
}
//组装查询条件
Student searchModel = new Student();
searchModel.setStuName(stuName);
searchModel.setGender(gender);
//调用service获取查询结果
Pager result = studentService.findStudent(searchModel, pageNum, pageSize);
//返回结果到页面
request.setAttribute("result", result);
request.setAttribute("stuName", stuName);
request.setAttribute("gender", gender);
request.getRequestDispatcher("jdbcSqlStudent.jsp").forward(request, response);
}
}
引用了github上https://github.com/gbirke/jquery_pagination的分页工具
导入了一个css文件和2个js文件
jdbcSqlStudent.jsp
<%@ page language="java" import="java.util.*"
contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"%>
学生信息
<%
//获取请求上下文
String context = request.getContextPath();
%>
${errorMsg }
学生信息列表：
查询的结果不存在
姓名
性别
年龄
家庭地址
男 女
好啦，完成啦
