JDBC+Servlet+jsp(分頁)
阿新 • • 發佈:2018-12-10
目錄:
1.匯入jar包;
2.建立實體類
3.建立dao層
4.建立service層
5.建立servlet層
6.jsp頁面
一.匯入jar包;
1.匯入mysql-connector-java-5.1.0-bin.jar包;
二.建立實體類
package com.ybb.entity; public class Goods { private int id; private String name; private double price; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public Goods(int id, String name, double price) { super(); this.id = id; this.name = name; this.price = price; } public Goods() { super(); // TODO Auto-generated constructor stub } }
三.建立dao層
BaseDao:封裝類(封裝對增刪改查的方法)
package com.ybb.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class BaseDao { private Connection coon; //獲取連線 public Connection getConnnection(){ try { //通過反射載入驅動 Class.forName("com.mysql.jdbc.Driver"); //連線資料庫 coon=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/school?useUnicode=true&characterEncoding=utf8", "ybb", "1234"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return coon; } //update users set name=? where id=?; //增刪改 public int update(String sql,Object[]objects){ int num=0; try { //連線 coon=getConnnection(); PreparedStatement ps=coon.prepareStatement(sql); if (objects!=null&&objects.length>0) { for (int i = 0; i < objects.length; i++) { //替換佔位符 ps.setObject((i+1), objects[i]); } } //ִ執行增刪改的操作 num=ps.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return num; } //查詢 public ResultSet getResultSet(String sql,Object[]objects){ ResultSet rs=null; try { //連線 coon = getConnnection(); PreparedStatement ps = coon.prepareStatement(sql); if (objects!=null&&objects.length>0) { for (int i = 0; i < objects.length; i++) { ps.setObject((i+1), objects[i]); } } //執行查詢操作 rs=ps.executeQuery(); } catch (Exception e) { // TODO: handle exception } return rs; } //關閉資源 public void close(Connection connection ,PreparedStatement ps , ResultSet rs){ try { if(connection !=null){ connection.close(); } if(ps !=null){ ps.close(); } if(rs !=null){ rs.close(); } } catch (SQLException e) { e.printStackTrace(); } } }
介面類 GoodsDao
package com.ybb.dao; import java.util.List; import com.ybb.entity.Goods; public interface GoodsDao { //查詢所有 public List<Goods> findGoods(); //增加 public int addGoods(Goods goods); 修改 public int updateGoods(Goods goods); 刪除 public int deleteGoods(int id); 分頁 public List<Goods> fengYe(int pageIndex,int pageSize); }
實現介面的類 GoodsDaoImpl
package com.ybb.dao;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import com.ybb.entity.Goods;
public class GoodsDaoImpl extends BaseDao implements GoodsDao{
//查詢所有
@Override
public List<Goods> findGoods() {
// TODO Auto-generated method stub
List<Goods>lt=new ArrayList<Goods>();
try {
String sql = "select * from goods";
Object[] objects = {};
//呼叫封裝類方法
ResultSet rs = this.getResultSet(sql, objects);
//遍歷放入集合中
while (rs.next()){
Goods goods=new Goods();
goods.setId(rs.getInt("id"));
goods.setName(rs.getString("name"));
goods.setPrice(rs.getDouble("price"));
lt.add(goods);
}
} catch (Exception e) {
// TODO: handle exception
}
return lt;
}
//增加
@Override
public int addGoods(Goods goods) {
// TODO Auto-generated method stub
int count=0;
String sql="insert into goods(name,price) values(?,?)";
Object[]objects={goods.getName(),goods.getPrice()};
//呼叫封裝類的方法
count=this.update(sql, objects);
return count;
}
//修改
@Override
public int updateGoods(Goods goods) {
// TODO Auto-generated method stub
int count=0;
String sql="update goods set name=?,price=? where id=?";
Object[]objects={goods.getName(),goods.getPrice(),goods.getId()};
count=this.update(sql, objects);
return count;
}
//刪除
@Override
public int deleteGoods(int id){
// TODO Auto-generated method stub
int count=0;
String sql="delete from goods where id=?";
Object[]objects={id};
count=this.update(sql, objects);
return count;
}
//分頁
@Override
public List<Goods> fengYe(int pageIndex, int pageSize) {
// TODO Auto-generated method stub
List<Goods>lt=null;
try {
lt=new ArrayList<Goods>();
String sql = "select * from goods limit ?,?";
Object[] objects = { pageIndex, pageSize };
ResultSet rs = this.getResultSet(sql, objects);
while (rs.next()) {
Goods goods=new Goods();
goods.setId(rs.getInt("id"));
goods.setName(rs.getString("name"));
goods.setPrice(rs.getDouble("price"));
lt.add(goods);
}
} catch (Exception e) {
// TODO: handle exception
}
return lt;
}
}
四.建立業務層(service)
package com.ybb.server;
import java.util.List;
import com.ybb.dao.GoodsDao;
import com.ybb.dao.GoodsDaoImpl;
import com.ybb.entity.Goods;
public class GoodsServer {
private GoodsDao goodsDao=new GoodsDaoImpl();
public GoodsDao getGoodsDao() {
return goodsDao;
}
public void setGoodsDao(GoodsDao goodsDao) {
this.goodsDao = goodsDao;
}
public List<Goods> findGoods(){
return goodsDao.findGoods();
}
public int addGoods(Goods goods){
return goodsDao.addGoods(goods);
}
public int updateGoods(Goods goods){
return goodsDao.updateGoods(goods);
}
public int deleteGoods(int id){
return goodsDao.deleteGoods(id);
}
public List<Goods> fengYe(int pageIndex,int pageSize){
return goodsDao.fengYe(pageIndex, pageSize);
}
}
五.建立servlet層
GoodsServlet:實現分頁
package com.ybb.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.ybb.entity.Goods;
import com.ybb.server.GoodsServer;
public class GoodsServlet extends HttpServlet {
public GoodsServlet() {
super();
}
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
//解決中文亂碼
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
//當前頁數
int pageIndex=1;
//頁量
int pageSize=3;
//總頁數
int pageCount=1;
//獲取從a標籤中傳輸的值(request.getParameter可以拿取表單的值,也可以拿取a標籤所傳輸的值)
String pageIndex2 = request.getParameter("pageIndex");
System.out.println(pageIndex2);
if (pageIndex2!=null&&!pageIndex2.equals("")) {
pageIndex = Integer.parseInt(pageIndex2);
}
GoodsServer goodsServer=new GoodsServer();
List<Goods>lt=goodsServer.findGoods();
//獲取總資料量
int total=lt.size();
//獲取總頁數
pageCount=total%pageSize==0?total/pageSize:(total/pageSize)+1;
//判定最小頁數為1,不能低於1
if (pageIndex<1) {
pageIndex=1;
//判定最大頁數不能高於總頁數
}else if (pageIndex>pageCount) {
pageIndex=pageCount;
}
int page=(pageIndex-1)*pageSize;
int size=pageSize;
List<Goods>lt1=goodsServer.fengYe(page, size);
//當前頁數
request.getSession().setAttribute("page",pageIndex);
//總頁數
request.getSession().setAttribute("count", pageCount);
//存放資料的集合
request.getSession().setAttribute("list", lt1);
response.sendRedirect("../index.jsp");
}
public void init() throws ServletException {
// Put your code here
}
}
六.jsp頁面
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<table border="1">
<tr>
<td>id</td>
<td>商品名</td>
<td>價格</td>
<td>操作</td>
</tr>
<c:forEach items="${list}" var="goods">
<tr>
<td>${goods.id}</td>
<td>${goods.name}</td>
<td>${goods.price}</td>
<td><a href="/JavaWeb-jdbc/servlet/ShanchuServlet?id=${goods.id}"><button onclick="delete1()">刪除</button></a></td>
</tr>
</c:forEach>
</table>
<p>
<a href="/JavaWeb-jdbc/add.jsp"><button>增加</button></a>
</p>
<p>
<span>共${count}頁/第${page}頁</span>
<a href="/JavaWeb-jdbc/servlet/GoodsServlet?pageIndex=1">首頁</a>
<a href="/JavaWeb-jdbc/servlet/GoodsServlet?pageIndex=${page-1}">上一頁</a>
<a href="/JavaWeb-jdbc/servlet/GoodsServlet?pageIndex=${page+1}">下一頁</a>
<a href="/JavaWeb-jdbc/servlet/GoodsServlet?pageIndex=${count}">尾頁</a>
</p>
</body>
</html>