8.修改 按條件查詢商品 分頁
阿新 • • 發佈：2018-02-19
edi spl stat htm != pic check ren lib
修改商品的原理圖
jsp頁面
edit.jsp
<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<HTML>
<HEAD>
<meta http-equiv="Content-Language" content="zh-cn">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<LINK href="${pageContext.request.contextPath}/admin/css/Style.css"
type="text/css" rel="stylesheet">
<script language="javascript"
src="${pageContext.request.contextPath}/admin/js/public.js"></script>
<script language="javascript"
src="${pageContext.request.contextPath}/admin/js/check.js"></script>
</HEAD>
<body>
<!--
上傳文件
enctype="multipart/form-data"
修改語句：update products set xxx xxx xxx where pid=?
偷偷的傳
-->
<form id="userAction_save_do" name="Form1" action="${pageContext.request.contextPath }/product" method="post" >
<!-- post提交方法添加一個隱藏域 -->
<input type="hidden" name="method" value="update"/>
<input type="hidden" name="pid" value="${product.pid }"/>
<table cellSpacing="1" cellPadding="5" width="100%" align="center"
bgColor="#eeeeee" style="border: 1px solid #8ba7e3" border="0">
<tr>
<td class="ta_01" align="center" bgColor="#afd1f3" colSpan="4"
height="26"><strong><STRONG>編輯商品</STRONG> </strong></td>
</tr>
<tr>
<td align="center" bgColor="#f5fafe" class="ta_01">商品名稱：</td>
<td class="ta_01" bgColor="#ffffff">
<input type="text" name="pname" class="bg" value="${product.pname }" /></td>
<td align="center" bgColor="#f5fafe" class="ta_01">商品價格：</td>
<td class="ta_01" bgColor="#ffffff">
<input type="text" name="price" class="bg" value="${product.price }" /></td>
</tr>
<tr>
<td align="center" bgColor="#f5fafe" class="ta_01">商品數量：</td>
<td class="ta_01" bgColor="#ffffff">
<input type="text" name="pnum" class="bg" value="${product.pnum }" /></td>
<td align="center" bgColor="#f5fafe" class="ta_01">商品類別：</td>
<td class="ta_01" bgColor="#ffffff">
<%-- 判斷類別
<c:if test="${product.category eq ‘計算機‘ }">selected</c:if> --%>
<select name="category" id="category">
<option value="">--選擇商品類加--</option>
<option value="文學" <c:if test="${product.category eq ‘文學‘ }">selected</c:if>>文學</option>
<option value="生活" <c:if test="${product.category eq ‘生活‘ }">selected</c:if>>生活</option>
<option value="計算機" <c:if test="${product.category eq ‘計算機‘ }">selected</c:if>>計算機</option>
<option value="外語" <c:if test="${product.category eq ‘外語‘ }">selected</c:if>>外語</option>
<option value="經營" <c:if test="${product.category eq ‘經營‘ }">selected</c:if>>經營</option>
<option value="勵誌" <c:if test="${product.category eq ‘勵誌‘ }">selected</c:if>>勵誌</option>
<option value="社科" <c:if test="${product.category eq ‘社科‘ }">selected</c:if>>社科</option>
<option value="學術" <c:if test="${product.category eq ‘學術‘ }">selected</c:if>>學術</option>
<option value="少兒" <c:if test="${product.category eq ‘少兒‘ }">selected</c:if>>少兒</option>
<option value="藝術" <c:if test="${product.category eq ‘藝術‘ }">selected</c:if>>藝術</option>
<option value="原版" <c:if test="${product.category eq ‘原版‘ }">selected</c:if>>原版</option>
<option value="科技" <c:if test="${product.category eq ‘科技‘ }">selected</c:if>>科技</option>
<option value="考試" <c:if test="${product.category eq ‘考試‘ }">selected</c:if>>考試</option>
<option value="生活百科" <c:if test="${product.category eq ‘生活百科‘ }">selected</c:if>>生活百科</option>
</select></td>
</tr>
<tr>
<td align="center" bgColor="#f5fafe" class="ta_01">商品圖片：</td>
<td class="ta_01" bgColor="#ffffff" colSpan="3">
<input type="file" name="upload" size="30" value="" /></td>
</tr>
<TR>
<TD class="ta_01" align="center" bgColor="#f5fafe">商品描述：</TD>
<TD class="ta_01" bgColor="#ffffff" colSpan="3">
<textarea name="description" cols="30" rows="3" style="WIDTH: 96%">${product.description}</textarea>
</TD>
</TR>
<TR>
<td align="center" colSpan="4" class="sep1"><img
src="${pageContext.request.contextPath}/admin/images/shim.gif">
</td>
</TR>
<tr>
<td class="ta_01" style="WIDTH: 100%" align="center" bgColor="#f5fafe" colSpan="4">
<!-- 提交 -->
<input type="submit"class="button_ok" value="確定">
<FONT face="宋體"> </FONT>
<!-- 重置 -->
<input type="reset" value="重置" class="button_cancel"> <FONT
face="宋體"> </FONT>
<!-- 返回 -->
<INPUT class="button_ok" type="button" onclick="history.go(-1)" value="返回" />
<span id="Label1"> </span>
</td>
</tr>
</table>
</form>
</body>
</HTML>
list.jsp
<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<HTML>
<HEAD>
<meta http-equiv="Content-Language" content="zh-cn">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link href="${pageContext.request.contextPath}/admin/css/Style.css"
rel="stylesheet" type="text/css" />
<script language="javascript"
src="${pageContext.request.contextPath}/admin/js/public.js"></script>
<script type="text/javascript">
//點擊添加的按鈕，跳轉到添加商品的頁面
function addProduct() {
//相當於超鏈接
window.location.href = "${pageContext.request.contextPath}/admin/products/add.jsp";
}
</script>
</HEAD>
<body>
<br>
<!--
按條件查詢
按條件查詢
按條件查詢
按條件查詢
按條件查詢
-->
<form id="Form1" name="Form1" action="${pageContext.request.contextPath}/product" method="post">
<input type="hidden" name="method" value="findByWhere"/>
<table cellSpacing="1" cellPadding="0" width="100%" align="center" bgColor="#f5fafe" border="0">
<TBODY>
<tr>
<td class="ta_01" align="center" bgColor="#afd1f3">
<strong>查詢 條 件</strong>
</td>
</tr>
<tr>
<td>
<table cellpadding="0" cellspacing="0" border="0" width="100%">
<tr>
<td height="22" align="center" bgColor="#f5fafe" class="ta_01">
商品編號:
</td>
<td class="ta_01" bgColor="#ffffff">
<input type="text" name="pid" size="15" id="Form1_userName" class="bg" />
</td>
<td height="22" align="center" bgColor="#f5fafe" class="ta_01">
類別:
</td>
<td class="ta_01" bgColor="#ffffff">
<select name="category" id="category">
<option value="" selected="selected">--選擇商品類加--</option>
<option value="文學">文學</option>
<option value="生活">生活</option>
<option value="計算機">計算機</option>
<option value="外語">外語</option>
<option value="經營">經營</option>
<option value="勵誌">勵誌</option>
<option value="社科">社科</option>
<option value="學術">學術</option>
<option value="少兒">少兒</option>
<option value="藝術">藝術</option>
<option value="原版">原版</option>
<option value="科技">科技</option>
<option value="考試">考試</option>
<option value="生活百科">生活百科</option>
</select>
</td>
</tr>
<tr>
<td height="22" align="center" bgColor="#f5fafe" class="ta_01">
商品名稱:
</td>
<td class="ta_01" bgColor="#ffffff">
<input type="text" name="pname" size="15" id="Form1_userName" class="bg" />
</td>
<td height="22" align="center" bgColor="#f5fafe" class="ta_01">價格區間(元)：</td>
<td class="ta_01" bgColor="#ffffff">
<input type="text" name="minprice" size="10" />-
<input type="text" name="maxprice" size="10" />
</td>
</tr>
<tr>
<td width="100" height="22" align="center" bgColor="#f5fafe"class="ta_01"></td>
<td class="ta_01" bgColor="#ffffff">
<font face="宋體" color="red"> </font>
</td>
<td align="right" bgColor="#ffffff" class="ta_01"><br><br></td>
<td align="right" bgColor="#ffffff" class="ta_01">
<button type="submit" id="search" name="search" value="查詢" class="button_view">
查詢
</button>
<input type="reset" name="reset" value="重置" class="button_view" />
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td class="ta_01" align="center" bgColor="#afd1f3"><strong>商品列表</strong>
</TD>
</tr>
<tr>
<td class="ta_01" align="right">
<!--
添加的按鈕
添加的按鈕
添加的按鈕
添加的按鈕
添加的按鈕
添加的按鈕
添加的按鈕
添加的按鈕
-->
<button type="button" id="add" name="add" value="添加;"
class="button_add" onclick="addProduct()">添加
</button>
</td>
</tr>
<tr>
<td class="ta_01" align="center" bgColor="#f5fafe">
<table cellspacing="0" cellpadding="1" rules="all"
bordercolor="gray" border="1" id="DataGrid1"
style="BORDER-RIGHT: gray 1px solid; BORDER-TOP: gray 1px solid; BORDER-LEFT: gray 1px solid; WIDTH: 100%; WORD-BREAK: break-all; BORDER-BOTTOM: gray 1px solid; BORDER-COLLAPSE: collapse; BACKGROUND-COLOR: #f5fafe; WORD-WRAP: break-word">
<tr
style="FONT-WEIGHT: bold; FONT-SIZE: 12pt; HEIGHT: 25px; BACKGROUND-COLOR: #afd1f3">
<td align="center" width="24%">序號</td>
<td align="center" width="18%">商品名稱</td>
<td align="center" width="9%">商品價格</td>
<td align="center" width="9%">商品數量</td>
<td width="8%" align="center">商品類別</td>
<td width="8%" align="center">編輯</td>
<td width="8%" align="center">刪除</td>
</tr>
<!-- for標簽想象增強for循環 for(數據類型 變量：要遍歷的集合) -->
<c:forEach var="p" items="${pList }" varStatus="vs"> <!-- varStatus用於叠代數據，從1開始 -->
<tr onmouseover="this.style.backgroundColor = ‘white‘"
onmouseout="this.style.backgroundColor = ‘#F5FAFE‘;">
<td style="CURSOR: hand; HEIGHT: 22px" align="center"
width="23">${vs.count }</td>
<td style="CURSOR: hand; HEIGHT: 22px" align="center"
width="18%">${p.pname }</td>
<td style="CURSOR: hand; HEIGHT: 22px" align="center"
width="8%">${p.price }</td>
<td style="CURSOR: hand; HEIGHT: 22px" align="center"
width="8%">${p.pnum }</td>
<td style="CURSOR: hand; HEIGHT: 22px" align="center">
${p.category }</td>
<!--
編輯修改
編輯修改
編輯修改
編輯修改
編輯修改
編輯修改
-->
<td align="center" style="HEIGHT: 22px" width="7%">
<a href="${pageContext.request.contextPath }/product?method=initUpdate&pid=${p.pid}">
<img
src="${pageContext.request.contextPath}/admin/images/i_edit.gif"
border="0" style="CURSOR: hand"> </a>
</td>
<td align="center" style="HEIGHT: 22px" width="7%"><a
href="#">
<img
src="${pageContext.request.contextPath}/admin/images/i_del.gif"
width="16" height="16" border="0" style="CURSOR: hand">
</a>
</td>
</tr>
</c:forEach>
</table>
</td>
</tr>
</TBODY>
</table>
</form>
</body>
</HTML>
三層架構
/**
* 商品的控制器
* @author mjl
*
*/
public class ProductServlet extends BaseServlet {
/**
* 添加商品
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void addProduct(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
/**
* 1.接收數據
* 2.封裝數據
* 3.處理數據
* 4.顯示數據
*/
//接收數據
Map<String,String[]> map=request.getParameterMap();
Product p=new Product();
try {
//封裝數據
BeanUtils.populate(p, map);
System.out.println(p);
//處理數據
ProductService ps=new ProductService();
//保存數據
ps.save(p);
//如果添加成功,重定向到findAll
response.sendRedirect(request.getContextPath()+"/product?method=findAll");
} catch (Exception e) {
e.printStackTrace();
//捕獲異常
request.setAttribute("msg", e.getMessage());
request.getRequestDispatcher("/admin/products/add.jsp").forward(request, response);
}
}
/**
* 查詢所有的商品
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void findAll(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
/**
* 1.接收數據
* 2.封裝數據
* 3.處理數據
* 4.顯示數據
*/
//沒有參數，也不用封裝
ProductService ps=new ProductService();
//查詢所有的商品的信息
List<Product> pList=ps.findAll();
//存入到request域對象中
request.setAttribute("pList", pList);
request.getRequestDispatcher("/admin/products/list.jsp").forward(request, response);
/*前後兩個頁面 有數據傳遞 用請求轉發，沒有則用重定向。
比如servlet查詢了數據需要在頁面顯示，就用請求轉發。
比如servlet做了update操作跳轉到其他頁面，就用重定向。*/
}
/**
* 初始化的修改頁面
* 用於點擊編輯按鈕跳轉到編輯頁面
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void initUpdate(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
/**
* 通過主鍵去查詢該條記錄
*/
String pid=request.getParameter("pid");
ProductService ps=new ProductService();
Product p=ps.findById(pid);
//存入到request域
/**
* 服務器端域對象 域對象可以共享數據
* servletContext 服務器啟動，ServletContext創建了，服務器關閉的時候，銷毀！與天地同壽！！被所有的資源共享。
* HttpSession 代表一次會話！打開瀏覽器開始，關閉瀏覽器結束。發送多次請求，得到多次響應。保存每個人相關的信息。
* request 代表一次請求。只能發送一次，發送完畢就銷毀。保存一些提示的信息，或者要顯示的數據的。
*/
request.setAttribute("product", p);
request.getRequestDispatcher("/admin/products/edit.jsp").forward(request, response);
}
/**
* 修改商品
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//獲取數據
Map<String,String[]> map=request.getParameterMap();
Product product=new Product();
try {
BeanUtils.populate(product, map);
ProductService ps=new ProductService();
ps.update(product);
//跳轉到頁面
//如果修改成功,重定向到findAll
response.sendRedirect(request.getContextPath()+"/product?method=findAll");
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 按條件查詢所有的商品
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void findByWhere(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//接收請求的參數
String pid=request.getParameter("pid");
String category=request.getParameter("category");
String pname=request.getParameter("pname");
String minprice=request.getParameter("minprice");
String maxprice=request.getParameter("maxprice");
//調用持久層
ProductService ps=new ProductService();
List<Product> pList=ps.findByWhere(pid,category,pname,minprice,maxprice);
request.setAttribute("pList", pList);
request.getRequestDispatcher("/admin/products/list.jsp").forward(request, response);
}
}
/**
* 商品業務層
* @author mjl
*
*/
public class ProductService {
/**
* 保存商品
* @param p
* @throws SQLException
* @throws MyException
*/
public void save(Product p) throws SQLException, MyException{
//自己維護主鍵
p.setPid(MyUUIDUtils.getUUID());
//先設置imgurl屬性值為Null
p.setImgUrl(null);
//調用持久層，保存數據
ProductDao dao=new ProductDao();
dao.save(p);
}
/**
* 查詢所有的商品
* @return
*/
public List<Product> findAll() {
ProductDao dao=new ProductDao();
return dao.findAll();
}
/**
* 通過主鍵查詢該條記錄
* @param pid
* @return
*/
public Product findById(String pid) {
ProductDao dao=new ProductDao();
return dao.findById(pid);
}
/**
* 修改商品
* @param product
*/
public void update(Product product) {
ProductDao dao=new ProductDao();
dao.update(product);
}
/**
* 按條件查詢
* @param pid
* @param category
* @param pname
* @param minprice
* @param maxprice
* @return
*/
public List<Product> findByWhere(String pid, String category, String pname, String minprice, String maxprice) {
ProductDao dao=new ProductDao();
return dao.findByWhere(pid,category,pname,minprice,maxprice);
}
public List<Product> findByCondition(String pid, String category, String pname, String minprice, String maxprice) {
ProductDao dao=new ProductDao();
return dao.findByCondition(pid,category,pname,minprice,maxprice);
}
}
/**
* 商品的持久層
* @author mjl
*
*/
public class ProductDao {
public void save(Product p) throws SQLException, MyException{
//使用DBUtils工具類
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
//編寫sql語句
String sql="insert into products values(?,?,?,?,?,?,?)";
Object [] params={p.getPid(),p.getPname(),p.getPrice(),p.getCategory(),p.getPnum(),p.getImgUrl(),p.getDescription()};
//執行sql語句，如果成功，返回1
int count=runner.update(sql, params);
if(count!=1){
throw new MyException("親，添加商品錯誤");
}
}
public List<Product> findAll() {
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
try {
return runner.query("select * from products", new BeanListHandler<Product>(Product.class));
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("查詢所有的商品錯誤了！");
}
}
public Product findById(String pid) {
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
try {
Product p=runner.query("select * from products where pid=?", new BeanHandler<Product>(Product.class),pid);
return p;
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("查詢該條記錄錯誤了！");
}
}
public void update(Product p) {
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
String sql="update products set pname=?,price=?,category=?,pnum=?,imgurl=?,description=? where pid=?";
Object [] params={p.getPname(),p.getPrice(),p.getCategory(),p.getPnum(),p.getImgUrl(),p.getDescription(),p.getPid()};
try {
runner.update(sql,params);
} catch (SQLException e) {
e.printStackTrace();
}
}
public List<Product> findByWhere(String pid, String category, String pname, String minprice, String maxprice) {
//創建集合，用來存儲參數
List<Object> list=new ArrayList<Object>();
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
//拼接sql語句
StringBuffer sb=new StringBuffer("select * from products where 1=1 ");
//判斷參數是否為空，如果不為空，說明用戶輸入了這些值，如果為空，說明沒有輸入
if(pid!=null && !pid.trim().isEmpty()){ //trim()去掉空格
//拼接sql語句
sb.append(" and pid like ? "); //like模糊查詢
list.add("%"+pid+"%");
}
if(category!=null && !category.trim().isEmpty()){ //trim()去掉空格
//拼接sql語句
sb.append(" and category = ? ");
list.add(category);
}
if(pname!=null && !pname.trim().isEmpty()){ //trim()去掉空格
//拼接sql語句
sb.append(" and pname = ? ");
list.add(pname);
}
if(minprice!=null && !minprice.trim().isEmpty()){ //trim()去掉空格
//拼接sql語句
sb.append(" and price > ? ");
}
if(maxprice!=null && !maxprice.trim().isEmpty()){ //trim()去掉空格
//拼接sql語句
sb.append(" and price < ? ");
list.add(maxprice);
}
//執行
try {
return runner.query(sb.toString(), new BeanListHandler<Product>(Product.class),list.toArray());
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
public List<Product> findByCondition(String pid, String category, String pname, String minprice, String maxprice) {
StringBuffer sb=new StringBuffer();
sb.append("select * from products where 1=1 ");
List<Object> list=new ArrayList();
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
if(pid!=null && !pid.trim().isEmpty()){
sb.append(" and pid like ? ");
list.add("%"+pid+"%");
}
if(category!=null && !category.trim().isEmpty()){
sb.append(" and category = ? ");
list.add(category);
}
if(pname!=null && !pname.trim().isEmpty()){
sb.append(" and pname = ? ");
list.add(pname);
}
if(minprice!=null && !minprice.trim().isEmpty()){
sb.append(" and price > ? ");
list.add(minprice);
}
if(maxprice!=null && !maxprice.trim().isEmpty()){
sb.append(" and price< ? ");
list.add(maxprice);
}
try {
return runner.query(sb.toString(), new BeanListHandler<Product>(Product.class),list.toArray());
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
}
分頁的實現
jsp頁面中，點擊全部商品跳轉servlet
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<script type="text/javascript"
src="${pageContext.request.contextPath}/js/my.js">
</script>
<script type="text/javascript">
</script>
<div id="divmenu">
<a
href="${pageContext.request.contextPath}/showProductByPage?category=文學">文學</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=生活">生活</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=計算機">計算機</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=外語">外語</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=經營">經管</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=勵誌">勵誌</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=社科">社科</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=學術">學術</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=少兒">少兒</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=藝術">藝術</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=原版">原版</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=科技">科技</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=考試">考試</a>
<a
href="${pageContext.request.contextPath}/showProductByPage?category=生活百科">生活百科</a>
<a href="${pageContext.request.contextPath}/product?method=findByPage" style="color:#FFFF00">全部商品目錄</a>
</div>
<div id="divsearch">
<form action="${pageContext.request.contextPath}/findProductBySearch"
method="post">
<table width="100%" border="0" cellspacing="0">
<tr>
<td style="text-align:right; padding-right:220px">
Search <input
type="text" name="name" class="inputtable" onkeyup="searchName();"
id="name" />
<input type="image" src="images/serchbutton.gif"
border="0" style="margin-bottom:-4px">
</td>
</tr>
</table>
</form>
</div>
<div id="content"
style="background-color:white;width:128px; text-align:left;margin-left:945px;color:black;float:left;margin-top: -20px;display: none">
</div>
ProductServlet處理業務邏輯
/**
* 分頁查詢
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void findByPage(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
/**
* 1.解決當前頁的問題
* 以後用戶在客戶端給我傳參數，如果參數為null,說明是第一頁，如果不為空，傳的是幾頁就是幾頁
* 2.每一頁顯示的條數的問題
*/
//1.解決當前頁的問題
int pageCode=getPageCode(request);
//2.解決每頁顯示的記錄條數
int pageSize=4;
//調用業務層
ProductService ps=new ProductService();
//分頁的查詢
PageBean page=ps.findByPage(pageCode,pageSize);
//存入
request.setAttribute("page", page);
request.getRequestDispatcher("/product_list.jsp").forward(request, response);
}
/**
* 獲取當前頁
* @param request
* @return
*/
public int getPageCode(HttpServletRequest request){
//獲取當前頁
String pc=request.getParameter("pc");
//判斷,說明pc沒有傳，說明第一次
if(pc==null){
return 1;
}else{
return Integer.parseInt(pc);
}
}
ProductService
/**
* 分頁的查詢
* @param pageCode
* @param pageSize
* @return
*/
public PageBean findByPage(int pageCode, int pageSize) {
ProductDao dao=new ProductDao();
return dao.finByPage(pageCode,pageSize);
}
ProductDao
/**
* 分頁的查詢
* @param pageCode
* @param pageSize
* @return
*/
public PageBean finByPage(int pageCode, int pageSize) {
//目的：創建PageBean對象，把所有的屬性數據全部搞定
PageBean<Product> page=new PageBean();
page.setPageCode(pageCode);
page.setPageSize(pageSize);
QueryRunner runner=new QueryRunner(MyJdbcUtils.getDataSource());
//設置總的記錄數
String countSql="select count(*) from products ";
String selSql="select * from products limit ?,?";
try {
//查詢總的記錄數
long totalCount=(long) runner.query(countSql, new ScalarHandler());
//設置總的記錄數
page.setTotalCount((int)totalCount);
//查詢每頁顯示的數據
List<Product> beanList=runner.query(selSql, new BeanListHandler<Product>(Product.class),(pageCode-1)*pageSize,pageSize);
//設置每頁顯示的數據
page.setBeanList(beanList);
} catch (SQLException e) {
e.printStackTrace();
}
return page;
}
product_list.jsp頁面顯示分頁內容
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>bookStore列表</title>
<%--導入css --%>
<link rel="stylesheet" href="css/main.css" type="text/css" />
</head>
<body class="main">
<jsp:include page="head.jsp" />
<jsp:include page="menu_search.jsp" />
<div id="divpagecontent">
<table width="100%" border="0" cellspacing="0">
<tr>
<td>
<div style="text-align:right; margin:5px 10px 5px 0px">
<a href="index.jsp">首頁</a> > 計算機 > 圖書列表
</div>
<table cellspacing="0" class="listcontent">
<tr>
<td>
<h1>商品目錄</h1>
<hr />
<h1>計算機</h1> 共${page.totalCount }種商品
<hr />
<div style="margin-top:20px; margin-bottom:5px">
<img src="images/productlist.gif" width="100%" height="38" />
</div>
<table cellspacing="0" class="booklist">
<!-- 一頁只有四個 對象，所以遍歷4次 -->
<tr>
<c:forEach var="p" items="${page.beanList }">
<td>
<div class="divbookpic">
<p>
<a href="product_info.jsp">
<img src="bookcover/101.jpg" width="115" height="129" border="0" />
</a>
</p>
</div>
<div class="divlisttitle">
<a href="product_info.jsp">書名:${p.pname }<br />售價:${p.price } </a>
</div>
</td>
</c:forEach>
</tr>
</table>
<div class="pagination">
<ul>
<c:if test="${page.pageCode>1 }">
<li class="disablepage">
<a href="${pageContext.request.contextPath }/product?method=findByPage&pc=${page.pageCode-1}" >上一頁</a>
</li>
</c:if>
<!--也可以產生這種循環 for(int i=1;i<=10;i++){} -->
<%--
目的：控制begin和end的值
邏輯：
當總頁數<=10,說明一共不超過10頁，讓begin=1,end=總頁數
當總頁數>10,讓begin=pageCode-5,end=pageCode+4
頭溢出：
如果當前頁=3，begin=3-5=-2
如果begin<1,讓begin=1,end=10
尾溢出：
如果end>總頁數，讓end=總頁數，begin=總頁數-9
--%>
<!-- 編寫邏輯 判斷開始頁碼結束頁碼-->
<c:choose>
<c:when test="${page.totalPage<=10 }">
<c:set var="begin" value="1" ></c:set>
<c:set var="end" value="${page.totalPage }"></c:set>
</c:when>
<c:otherwise>
<c:set var="begin" value="${page.pageCode-5 }" ></c:set>
<c:set var="end" value="${page.pageCode+4 }"></c:set>
<!-- 判斷頭溢出 -->
<c:if test="${begin<1 }">
<c:set var="begin" value="1" ></c:set>
<c:set var="end" value="10"></c:set>
</c:if>
<!-- 判斷尾溢出 -->
<c:if test="${end>page.totalPage }">
<c:set var="begin" value="${page.totalPage-9 }" ></c:set>
<c:set var="end" value="${page.totalPage }"></c:set>
</c:if>
</c:otherwise>
</c:choose>
<c:forEach var="i" begin="${begin }" end="${end }" step="1">
<!-- 當前頁==i -->
<c:if test="${page.pageCode==i }">
<li class="currentpage">${i }</li>
</c:if>
<c:if test="${page.pageCode!=i }">
<li><a href="${pageContext.request.contextPath }/product?method=findByPage&pc=${i}">${i }</a>
</c:if>
</c:forEach>
<c:if test="${page.pageCode<page.totalPage }">
<li class="nextpage">
<a href="${pageContext.request.contextPath }/product?method=findByPage&pc=${page.pageCode+1}">下一頁</a>
</li>
</c:if>
</ul>
</div>
</td>
</tr>
</table>
</td>
</tr>
</table>
</div>
<jsp:include page="foot.jsp" />
</body>
</html>
8.修改 按條件查詢商品 分頁