在javaee中Model1模型是以jsp頁面為中心的，jsp既要對瀏覽器的request做出邏輯處理（使用javabean），訪問數據庫也要顯示出相關的頁面。
在model1模型中，沒有servlet。
Model1結果圖如下：
Model1的可維護性可擴展性都是較差的只適合小項目。
首先運行結果
goods.jsp
<%@page import="entity.Items"%> <%@page import="dao.ItemsDao"%> <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% 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"> --> <style type="text/css"> div { float: left; margin: 10px; } div dd { margin: 0px; font-size: 10pt; } div dd.dd_name { color: blue; } div dd.dd_city { color: #000; } </style> </head> <body> <center> <h1>商品展示</h1> <hr> <table cellpadding="0" cellspacing="0" > <tr> <td> <% ItemsDao dao = new ItemsDao(); ArrayList<Items> list = new ArrayList<Items>(); //從dao中獲取所有的商品並保存到list集合中list = dao.getAllItems(); if (list != null && list.size() > 0) { //循環遍歷集合併顯示for (int i = 0; i < list.size(); i++) { Items item = list.get(i); %> <div> <dl> <dt> <a href="details.jsp?id=<%=item.getId()%>"><img src="images/<%=item.getPicture()%>" /> </a> </dt> <dd><%=item.getName()%></dd> <dd> 產地:<%=item.getCity()%> 價格:￥ <%=item.getPrice()%></dd> </dl> </div> <% } } %> </td> </tr> </table> </center> </body> </html>在代碼中表示商品的圖片
<span style="white-space:pre"> </span><a href="details.jsp?id=<%=item.getId()%>"><img src="images/<%=item.getPicture()%>" /> </a>
通過點擊商品的圖片把當前商品的id傳值給details頁面
details.jsp通過商品的id來顯示詳細商品，而瀏覽記錄由cookies維護
<%@page import="org.apache.taglibs.standard.tag.common.xml.ForEachTag"%> <%@page import="entity.Items"%> <%@page import="dao.ItemsDao"%> <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% 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"> <style type="text/css"> #historyview { border: 1; background: #EAEAEE; } #historyview td { font-size: 10px; } </style> </head> <body> <center> <h1>商品詳情</h1> <hr> <table cellpadding="0" cellspacing="0"> <tr> <td> <center> <table> <% ItemsDao dao = new ItemsDao(); //根據request傳來的商品id 向dao中獲得相對應的商品對象Items item = dao.getItemById(Integer.parseInt(request .getParameter("id"))); if (item != null) { %> <tr> <td rowspan="5"><img src="images/<%=item.getPicture()%>" ></td> </tr> <tr> <td><b><%=item.getName()%></b> </td> </tr> <tr> <td id="cityname">產地：<%=item.getCity()%></td> </tr> <tr> <td id="pricename">價格：<%=item.getPrice()%> ￥</td> </tr> <tr> <td id="pricename">價格：<%=item.getPrice()%> ￥</td> </tr> <% } //將該商品加入cookies Cookie[] cookies = request.getCookies(); String historyStr = ""; for (Cookie c : cookies) { if (c.getName().equals("history")) { historyStr = c.getValue(); } } historyStr += item.getId() + ","; Cookie c = new Cookie("history", historyStr); //重新設置cookies response.addCookie(c); %> </table> </center></td> <td valign="top" id="historyview"> <center> <table> <tr> <td><b>你瀏覽過的商品</b></td> </tr> <% //根據cookie 從dao獲取最後瀏覽的三次記錄並保存到list集合ArrayList<Items> historyItems = dao.getHistoryView(historyStr); if (historyItems != null && historyItems.size() > 0) { //遍歷集合for (Items historyItem : historyItems) { %> <tr> <td><a href="details.jsp?id=<%=historyItem.getId()%>"><img src="images/<%=historyItem.getPicture()%>" > </a></td> </tr> <tr> <td><b><%=historyItem.getName()%></b> </td> </tr> <tr> <td>產地：<%=historyItem.getCity()%></td> </tr> <% } } %> </table> </center> </td> </tr> </table> </center> </body> </html> dao層負責商品在數據庫中的查詢操作
package dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import util.DBHelper; import entity.Items; //商品的業務邏輯類public class ItemsDao { // 獲得所有商品信息public ArrayList<Items> getAllItems() { // 商品集合ArrayList<Items> list = new ArrayList<Items>(); Connection conn = null; PreparedStatement ps = null; ResultSet rs = null; try { conn = DBHelper.getConnection(); String sql = "select * from items";// sql 語句ps = conn.prepareStatement(sql); rs = ps.executeQuery(); // 將查詢的結果依次加入集合while (rs.next()) { Items item = new Items(); item.setId(rs.getInt("id")); item.setName(rs.getString("name")); item.setCity(rs.getString("city")); item.setPrice(rs.getDouble("price")); item.setPicture(rs.getString("picture")); item.setNumber(rs.getInt("number")); list.add(item); } } catch (SQLException e) { e.printStackTrace(); } finally { // 關閉資源if (rs != null) { try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if (ps != null) { try { ps.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } return list; } // 根據商品編號獲取商品資料public Items getItemById(int id) { Items item = new Items(); Connection con = null; PreparedStatement ps = null; ResultSet rs = null; String sql = "select * from items where id = ?"; try { con = DBHelper.getConnection(); ps = con.prepareStatement(sql); ps.setInt(1, id); rs = ps.executeQuery(); // 如果找到該id 為item對像初始化if (rs.next()) { item.setId(rs.getInt("id")); item.setName(rs.getString("name")); item.setCity(rs.getString("city")); item.setPrice(rs.getDouble("price")); item.setPicture(rs.getString("picture")); item.setNumber(rs.getInt("number")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { // 關閉資源if (rs != null) { try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if (ps != null) { try { ps.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } return item; } // 根據cookie 獲得瀏覽的最後三個商品public ArrayList<Items> getHistoryView(String cookie) { ArrayList<Items> list = new ArrayList<Items>(); String ids[] = cookie.split(","); int counts = 3;// 瀏覽的最後三條記錄if (ids != null && ids.length > 0) { for (int i = ids.length - 1; i >= 0 && i > ids.length - counts - 1; i--) { Items item = getItemById(Integer.parseInt(ids[i])); /* * 首先判斷集合中是否存在當前物品如果存在counts+1 多讀取一次（保證list集合中有3個對象） 不添加此物品*/ if (list.contains(item)) { counts++; continue; } list.add(item); } } return list; } }商品的實體類Items
package entity; public class Items { private int id; private String name; private String city; private double price; private int number; private String picture; 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 String getCity() { return city; } public void setCity(String city) { this.city = city; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public int getNumber() { return number; } public void setNumber(int number) { this.number = number; } public String getPicture() { return picture; } public void setPicture(String picture) { this.picture = picture; } @Override public int hashCode() { // TODO Auto-generated method stub return this.getId()+this.getName().hashCode(); } @Override public boolean equals(Object obj) { if(this==obj) { return true; } else { if(obj instanceof Items) { Items item=(Items) obj; if(this.getId()==item.getId()&&this.getName().equals(item.getName())) { return true; } } } return false; } }在這裡重寫了hasCode和equals方法來修改比較方式（所有的item都是一個新的對象即使兩個商品的內容全部一樣也不會相等。所以要修改比較方式）
因為對於瀏覽記錄而言我們不能通過刷新當前商品瀏覽記錄全部都是該商品我們只要保證該商品在瀏覽記錄中只有一個即可所以在dao層中的getHistoryView方法有這句代碼
<span style="white-space:pre"> </span>if (list.contains(item)) { counts++; continue; }然後是工具類
DBHelpher單例模式獲得connection對象
package util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class DBHelper { private static final String driver = "com.mysql.jdbc.Driver"; private static final String url = "jdbc:mysql://localhost:3306/shopping?useUnicode=true&charcterEncoding=UTF-8"; private static final String username = "root"; private static final String password = "123"; private static Connection con = null; // 靜態塊代碼負責加載驅動static { try { Class.forName(driver); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static Connection getConnection() { if (con == null) { try { con = DriverManager.getConnection(url, username, password); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return con; } }以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。