网上图书商城项目学习笔记-011Book模块查询(分页)
2016-01-27 14:59
501 查看
一、流程分析
1.图书模块
2.分布分析
二、代码
1.view层
1）list.jsp
2)pager.jsp
2.servlet层
1）BookServlet.java
3.service层
1）BookService.java
4.dao层
1）BookDao.java
1.图书模块
2.分布分析
二、代码
1.view层
1）list.jsp
<%@ 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>图书列表</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">
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link rel="stylesheet" type="text/css" href="<c:url value='/jsps/css/book/list.css'/>">
<link rel="stylesheet" type="text/css" href="<c:url value='/jsps/pager/pager.css'/>" />
<script type="text/javascript" src="<c:url value='/jsps/pager/pager.js'/>"></script>
<script type="text/javascript" src="<c:url value='/jquery/jquery-1.5.1.js'/>"></script>
<script type="text/javascript" src="<c:url value='/jsps/js/book/list.js'/>"></script>
</head>
<body>
<ul>
<c:forEach items="${pb.beanList }" var="book">
<li>
<div class="inner">
<a class="pic" href="<c:url value='/BookServlet?method=load&bid=${book.bid }'/>"><img src="<c:url value='/${book.image_b }'/>" border="0"/></a>
<p class="price">
<span class="price_n">¥${book.currPrice }</span>
<span class="price_r">¥${book.price }</span>
(<span class="price_s">${book.discount }折</span>)
</p>
<p><a id="bookname" title="${book.bname }" href="<c:url value='/jsps/book/desc.jsp'/>">${book.bname }</a></p>
<%-- url标签会自动对参数进行url编码 --%>
<c:url value="/BookServlet" var="authorUrl">
<c:param name="mehtod" value="findByAuthor" />
<c:param name="author" value="${book.author }" />
</c:url>
<c:url value="/BookServlet" var="pressUrl">
<c:param name="mehtod" value="findByPress"/>
<c:param name="press" value="${book.press }"/>
</c:url>
<p><a href="<c:url value='${authorUrl }'/>" name='P_zz' title='${book.author }'>${book.author }</a></p>
<p class="publishing">
<span>出 版 社：</span><a href="<c:url value='${pressUrl }'/>">${book.press }</a>
</p>
<p class="publishing_time"><span>出版时间：</span>${book.publishtime }</p>
</div>
</li>
</c:forEach>
<!--
<li>
<div class="inner">
<a class="pic" href="<c:url value='/jsps/book/desc.jsp'/>"><img src="<c:url value='/book_img/23254532-1_b.jpg'/>" border="0"/></a>
<p class="price">
<span class="price_n">¥40.7</span>
<span class="price_r">¥50.9</span>
(<span class="price_s">6.9折</span>)
</p>
<p><a id="bookname" title="Spring实战(第3版)（In Action系列中最畅销的Spring图书，近十万读者学习Spring的共同选择）" href="<c:url value='/jsps/book/desc.jsp'/>">Spring实战(第3版)（In Action系列中最畅销的Spring图书，近十万读者学习Spring的共同选择）</a></p>
<p><a href="<c:url value='/jsps/book/list.jsp'/>" name='P_zz' title='Craig Walls'>Craig Walls</a></p>
<p class="publishing">
<span>出 版 社：</span><a href="<c:url value='/jsps/book/list.jsp'/>">人民邮电出版社</a>
</p>
<p class="publishing_time"><span>出版时间：</span>2013-06-01</p>
</div>
</li>
<li>
<div class="inner">
<a class="pic" href="<c:url value='/jsps/book/desc.jsp'/>"><img src="<c:url value='/book_img/23254532-1_b.jpg'/>" border="0"/></a>
<p class="price">
<span class="price_n">¥40.7</span>
<span class="price_r">¥50.9</span>
(<span class="price_s">6.9折</span>)
</p>
<p><a id="bookname" title="Spring实战(第3版)（In Action系列中最畅销的Spring图书，近十万读者学习Spring的共同选择）" href="<c:url value='/jsps/book/desc.jsp'/>">Spring实战(第3版)（In Action系列中最畅销的Spring图书，近十万读者学习Spring的共同选择）</a></p>
<p><a href="<c:url value='/jsps/book/list.jsp'/>" name='P_zz' title='Craig Walls'>Craig Walls</a></p>
<p class="publishing">
<span>出 版 社：</span><a href="<c:url value='/jsps/book/list.jsp'/>">人民邮电出版社</a>
</p>
<p class="publishing_time"><span>出版时间：</span>2013-06-01</p>
</div>
</li>
-->
</ul>
<div style="float:left; width: 100%; text-align: center;">
<hr/>
<br/>
<%@include file="/jsps/pager/pager.jsp" %>
</div>
</body>
</html>2)pager.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<script type="text/javascript">
function _go() {
var pc = $("#pageCode").val();//获取文本框中的当前页码
if(!/^[1-9]\d*$/.test(pc)) {//对当前页码进行整数校验
alert('请输入正确的页码！');
return;
}
if(pc > ${pb.totalPages}) {//判断当前页码是否大于最大页
alert('请输入正确的页码！');
return;
}
location = "${pb.url}&pc=" + pc;
}
</script>
<div class="divBody">
<div class="divContent">
<%--上一页 --%>
<c:choose>
<c:when test="${pb.currentPage eq 1 }"><span class="spanBtnDisabled">上一页</span></c:when>
<c:otherwise> <a href="${pb.url }&pb=${pb.currentPage-1}" class="aBtn bold">上一页</a></c:otherwise>
</c:choose>
<%--我们需要计算页码列表的开始和结束位置，即两个变量begin和end,设定总共显示6页
计算它们需要通过当前页码！
1. 总页数不足6页--> begin=1, end=最大页
2. 总页数大于6页，通过公式设置begin和end，begin=当前页-2，end=当前页+3，因为假定总共显示6页
3. 如果begin<1，那么让begin=1，end=6
4. 如果end>tp, 让begin=tp-5, end=tp
--%>
<c:choose>
<c:when test="${pb.totalPages <= 6 }">
<c:set var="begin" value="1"/>
<c:set var="end" value="${pb.totalPages }"/>
</c:when>
<c:otherwise>
<c:set var="begin" value="${pb.currentPage -2 }"/>
<c:set var="end" value="${pb.currentPage + 3 }"/>
<c:if test="${begin < 1 }">
<c:set var="begin" value="1"/>
<c:set var="end" value="6"/>
</c:if>
<c:if test="${end > pb.totalPages }">
<c:set var="begin" value="${pb.totalPages - 5 }"/>
<c:set var="end" value="${pb.totalPages }"/>
</c:if>
</c:otherwise>
</c:choose>
<%-- 显示页码列表 --%>
<c:forEach begin="${begin }" end="${end }" var="i">
<c:choose>
<c:when test="${i eq pb.currentPage }"><span class="spanBtnSelect">${i }</span></c:when>
<c:otherwise><a href="${pb.url }&pc=${i}" class="aBtn">${i}</a></c:otherwise>
</c:choose>
</c:forEach>
<%-- 显示点点点 --%>
<c:if test="${end < pb.totalPages }"><span class="spanApostrophe">...</span> </c:if>
<%--下一页 --%>
<c:choose>
<c:when test="${pb.currentPage eq pb.totalPages }"><span class="spanBtnDisabled">下一页</span></c:when>
<c:otherwise><a href="${pb.url }&pc=${pb.currentPage+1}" class="aBtn bold">下一页</a> </c:otherwise>
</c:choose>
<%-- 共N页 到M页 --%>
<span>共${pb.totalPages}页</span>
<span>到</span>
<input type="text" class="inputPageCode" id="pageCode" value="${pb.currentPage }"/>
<span>页</span>
<a href="javascript:_go();" class="aSubmit">确定</a>
</div>
</div>2.servlet层
1）BookServlet.java
package com.tony.goods.book.web.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.itcast.servlet.BaseServlet;
import com.tony.goods.book.domain.Book;
import com.tony.goods.book.service.BookService;
import com.tony.goods.pager.PageBean;
public class BookServlet extends BaseServlet {
private BookService bookService = new BookService();
/**
* 按分类查
* @param req
* @param resp
* @return
* @throws ServletException
* @throws IOException
*/
public String findByCategory(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// 1. 得到currentPage：如果页面传递，使用页面的，如果没传，currentPage=1
int currentPage = getCurrentPage(req);
// 2. 得到url：...
String url = getUrl(req);
// 3. 获取查询条件，本方法就是cid，即分类的id
String cid = req.getParameter("cid");
// 4. 使用currentPage和cid调用service#findByCategory得到PageBean
PageBean<Book> pb = bookService.findByCategory(cid, currentPage);
pb.setUrl(url);
pb.setCurrentPage(currentPage);
req.setAttribute("pb", pb);
return "f:/jsps/book/list.jsp";
}
/**
* 截取url，页面中的分页导航中需要使用它做为超链接的目标！
* @param req
* @return
*/
/*
* http://localhost:8080/goods/BookServlet?methed=findByCategory&cid=xxx&pc=3 * /goods/BookServlet + methed=findByCategory&cid=xxx&pc=3
*/
private String getUrl(HttpServletRequest req) {
String url = req.getRequestURI() + "?" + req.getQueryString();
// 如果url中存在pc参数，截取掉，如果不存在那就不用截取。
int index = url.lastIndexOf("&pc=");
if(index != -1)
url = url.substring(0, index);
return url;
}
/**
* 获取当前页码
* @param req
* @return
*/
private int getCurrentPage(HttpServletRequest req) {
int currentPage = 1;
String param = req.getParameter("pc");
if(param != null && !param.trim().isEmpty()) {
try {
currentPage = Integer.parseInt(param);
} catch (Exception e) {
e.printStackTrace();
}
}
return currentPage;
}
}3.service层
1）BookService.java
package com.tony.goods.book.web.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.itcast.servlet.BaseServlet;
import com.tony.goods.book.domain.Book;
import com.tony.goods.book.service.BookService;
import com.tony.goods.pager.PageBean;
public class BookServlet extends BaseServlet {
private BookService bookService = new BookService();
/**
* 按分类查
* @param req
* @param resp
* @return
* @throws ServletException
* @throws IOException
*/
public String findByCategory(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// 1. 得到currentPage：如果页面传递，使用页面的，如果没传，currentPage=1
int currentPage = getCurrentPage(req);
// 2. 得到url：...
String url = getUrl(req);
// 3. 获取查询条件，本方法就是cid，即分类的id
String cid = req.getParameter("cid");
// 4. 使用currentPage和cid调用service#findByCategory得到PageBean
PageBean<Book> pb = bookService.findByCategory(cid, currentPage);
pb.setUrl(url);
pb.setCurrentPage(currentPage);
req.setAttribute("pb", pb);
return "f:/jsps/book/list.jsp";
}
/**
* 截取url，页面中的分页导航中需要使用它做为超链接的目标！
* @param req
* @return
*/
/*
* http://localhost:8080/goods/BookServlet?methed=findByCategory&cid=xxx&pc=3 * /goods/BookServlet + methed=findByCategory&cid=xxx&pc=3
*/
private String getUrl(HttpServletRequest req) {
String url = req.getRequestURI() + "?" + req.getQueryString();
// 如果url中存在pc参数，截取掉，如果不存在那就不用截取。
int index = url.lastIndexOf("&pc=");
if(index != -1)
url = url.substring(0, index);
return url;
}
/**
* 获取当前页码
* @param req
* @return
*/
private int getCurrentPage(HttpServletRequest req) {
int currentPage = 1;
String param = req.getParameter("pc");
if(param != null && !param.trim().isEmpty()) {
try {
currentPage = Integer.parseInt(param);
} catch (Exception e) {
e.printStackTrace();
}
}
return currentPage;
}
}4.dao层
1）BookDao.java
package com.tony.goods.book.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 cn.itcast.jdbc.TxQueryRunner;
import com.tony.goods.book.domain.Book;
import com.tony.goods.pager.Expression;
import com.tony.goods.pager.PageBean;
import com.tony.goods.pager.PageConfig;
public class BookDao {
private QueryRunner qr = new TxQueryRunner();
/**
* 删除图书
* @param bid
* @throws SQLException
*/
public void delete(String bid) throws SQLException {
String sql = "delete from t_book where bid=?";
qr.update(sql, bid);
}
/**
* 按分类查询
* @param cid
* @param currentPage
* @return
* @throws SQLException
*/
public PageBean<Book> findByCategory(String cid, int currentPage) throws SQLException {
List<Expression> exprList = new ArrayList<Expression>();
exprList.add(new Expression("cid", "=", cid));
return findByCriteria(exprList, currentPage);
}
/**
* 按书名模糊查询
* @param bname
* @param currentPage
* @return
* @throws SQLException
*/
public PageBean<Book> findByBname(String bname, int currentPage) throws SQLException {
List<Expression> exprList = new ArrayList<Expression>();
exprList.add(new Expression("bname", "like", "%" + bname + "%"));
return findByCriteria(exprList, currentPage);
}
/**
* 按作者查
* @param author
* @param currentpage
* @return
* @throws SQLException
*/
public PageBean<Book> findByAuthor(String author, int currentpage) throws SQLException {
List<Expression> exprList = new ArrayList<Expression>();
exprList.add(new Expression("author", "like", "%" + author + "%"));
return findByCriteria(exprList, currentpage);
}
/**
* 按出版社查
* @param press
* @param currentpage
* @return
* @throws SQLException
*/
public PageBean<Book> findByPress(String press, int currentpage) throws SQLException {
List<Expression> exprList = new ArrayList<Expression>();
exprList.add(new Expression("press", "like", "%" + press + "%"));
return findByCriteria(exprList, currentpage);
}
/**
* 多条件组合查询
* @param criteria
* @param currentPage
* @return
* @throws SQLException
*/
public PageBean<Book> findByCombination(Book criteria, int currentPage) throws SQLException {
List<Expression> exprList = new ArrayList<Expression>();
exprList.add(new Expression("bname", "like", "%" + criteria.getBname() + "%"));
exprList.add(new Expression("author", "like", "%" + criteria.getAuthor() + "%"));
exprList.add(new Expression("press", "like", "%" + criteria.getPress() + "%"));
return findByCriteria(exprList, currentPage);
}
/**
* 通用的查询方法
* @param exprList
* @param currentPage
* @return
* @throws SQLException
*/
private PageBean<Book> findByCriteria(List<Expression> exprList,
int currentPage) throws SQLException {
/*
* 1. 得到pageSize
* 2. 得到totalRecords
* 3. 得到beanList
* 4. 创建PageBean，返回
*/
/*
* 1. 得到pageSize
*/
int pageSize = PageConfig.BOOK_PAGE_SIZE;
/*
* 2. 通过exprList来生成where子句
*/
StringBuilder whereSql = new StringBuilder(" where 1=1");
List<Object> params = new ArrayList<Object>();
for(Expression expr : exprList) {
/*
* 添加一个条件上，
* 1) 以and开头
* 2) 条件的名称
* 3) 条件的运算符，可以是=、!=、>、< ... is null，is null没有值
* 4) 如果条件不是is null，再追加问号，然后再向params中添加一与问号对应的值
*/
whereSql.append(" and ").append(expr.getName())
.append(" ").append(expr.getOperator()).append(" ");
// where 1=1 and bid = ?
if(!expr.getOperator().equalsIgnoreCase("is null")) {
whereSql.append("?");
params.add(expr.getValue());
}
}
/*
* 3. 总记录数
*/
String sql = "select count(*) from t_book" + whereSql;
Number count = (Number) qr.query(sql, new ScalarHandler(), params.toArray());
int totalRecords = count.intValue();//得到了总记录数
/*
* 4. 得到beanList，即当前页记录
*/
sql = "select * from t_book" + whereSql + "order by orderBy limit ?,?";
params.add((currentPage - 1) * pageSize);//当前页首行记录的下标
params.add(pageSize);//每页记录数
List<Book> beanList = qr.query(sql, new BeanListHandler<Book>(Book.class), params.toArray());
/*
* 5. 创建PageBean，设置参数
*/
PageBean<Book> pb = new PageBean<Book>();
/*
* 其中PageBean没有url，这个任务由Servlet完成
*/
pb.setBeanList(beanList);
pb.setCurrentPage(currentPage);
pb.setPageSize(pageSize);
pb.setTotalRecords(totalRecords);
return pb;
}
}
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