图书模块
分析
在设计图书管理的时候，我们应该想到：图书和分类是有关系的。一个分类可以对应多本图书。
为什么要这样设计？这样更加人性化，用户在购买书籍的时候，用户能够查看相关分类后的图书，而不是全部图书都显示给用户，让用户一个一个去找。
设计实体
private String id;
private String name;
private String author;
private String description;
private double price;
//记住图片的名称
private String image;
//记住分类的id
private String category_id;
//各种setter和getter设计数据库表
CREATE TABLE book (
id VARCHAR(40) PRIMARY KEY,
name VARCHAR(10) NOT NULL UNIQUE,
description VARCHAR(255),
author VARCHAR(10),
price FLOAT,
image VARCHAR(100),
category_id VARCHAR(40),
CONSTRAINT category_id_FK FOREIGN KEY (category_id) REFERENCES category (id)
);
编写DAO
/**
* 图书模块
* 1：添加图书
* 2：查看图书
* 3：查找图书的分页数据【图书一般来说有很多，所以要分页】
*/
public class BookDaoImpl {
public void addBook(Book book) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "INSERT INTO book (id,name,description,author,price,image,category_id) VALUES(?,?,?,?,?,?,?)";
try {
queryRunner.update(sql, new Object[]{book.getId(), book.getName(), book.getDescription(), book.getAuthor(), book.getPrice(),book.getImage(), book.getCategory_id()});
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
public Book findBook(String id) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT * FROM book WHERE id=?";
try {
return (Book) queryRunner.query(sql, id, new BeanHandler(Book.class));
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
/**得到图书的分页数据*/
public List<Book> getPageData(int start, int end) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT * FROM book limit ?,?";
try {
return (List<Book>) queryRunner.query(sql, new BeanListHandler(Book.class), new Object[]{start, end});
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
/**得到按照分类图书的分页数据*/
public List<Book> getPageData(int start, int end,String category_id) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
//WHERE字句在limit字句的前边，注意Object[]的参数位置！
String sql = "SELECT * FROM book WHERE category_id=? limit ?,?";
try {
return (List<Book>) queryRunner.query(sql, new BeanListHandler(Book.class), new Object[]{ category_id,start, end});
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
/**
* 得到图书的总记录数
*/
public int getTotalRecord() {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT COUNT(*) FROM book";
try {
return (int) queryRunner.query(sql, new ScalarHandler());
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
/**
* 得到分类后图书的总记录数
* getCategoryTotalRecord
*/
public long getCategoryTotalRecord(String category_id) {
try {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT COUNT(*) FROM book WHERE category_id=?";
return (long) queryRunner.query(sql, category_id, new ScalarHandler());
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}测试DAO
public class BookDemo {
BookDaoImpl bookDao = new BookDaoImpl();
@Test
public void add() {
Book book = new Book();
book.setId("5");
book.setName("SQLServer");
book.setAuthor("我也不知道");
book.setImage("33333332432");
book.setPrice(33.22);
book.setDescription("这是一本好书");
book.setCategory_id("2");
bookDao.addBook(book);
}
@Test
public void look() {
List<Book> bookList = bookDao.getPageData(3, 3);
for (Book book : bookList) {
System.out.println(book.getName());
}
List<Book> books = bookDao.getPageData(0,2,"2");
for (Book book : books) {
System.out.println(book.getName());
}
}
@Test
public void find() {
String id = "2";
Book book = bookDao.findBook(id);
System.out.println(book.getName());
}
}
抽取成DAO接口
public interface BookDao {
void addBook(Book book);
Book findBook(String id);
List<Book> getPageData(int start, int end);
List<Book> getPageData(int start, int end, String category_id);
long getTotalRecord();
long getCategoryTotalRecord(String category_id);
}
编写Service层
/*添加图书*/
public void addBook(Book book) {
bookDao.addBook(book);
}
/*查找图书*/
public Book findBook(String id) {
return bookDao.findBook(id);
}
/*查找图书*/
public Book findBook(String id) {
return bookDao.findBook(id);
}
/*获取图书的分页数据*/
public Page getPageData(String pageNum) {
Page page=null;
if (pageNum == null) {
page = new Page(1, bookDao.getTotalRecord());
} else {
page = new Page(Integer.valueOf(pageNum), bookDao.getTotalRecord());
}
List<Book> books = bookDao.getPageData(page.getStartIndex(), page.getLinesize());
page.setList(books);
return page;
}
/*获取图书分类后的分页数据*/
public Page getPageData(String currentPageCount,String category_id) {
Page page=null;
if (currentPageCount == null) {
page = new Page(1, bookDao.getCategoryTotalRecord(category_id));
} else {
page = new Page(Integer.valueOf(currentPageCount), bookDao.getCategoryTotalRecord(category_id));
}
List<Book> books = bookDao.getPageData(page.getStartIndex(), page.getLinesize(), category_id);
page.setList(books);
return page;
}
后台添加图书
后台要添加图书的时候，应该说明图书的类型是什么。
要想在显示添加图书的页面上知道全部类型的id，就要经过Servlet把类型的集合传送过去
绑定链接
<a href="${pageContext.request.contextPath}/BookServlet?method=addUI" target="body">添加图书</a><br>传送类型集合的Servlet
String method = request.getParameter("method");
BussinessServiceImpl service = new BussinessServiceImpl();
if (method.equals("addUI")) {
List<Category> list = service.getAllCategory();
request.setAttribute("list", list);
request.getRequestDispatcher("/background/addBook.jsp").forward(request, response);
} 显示JSP页面
<form action="${pageContext.request.contextPath}/BookServlet?method=add" method="post" enctype="multipart/form-data">
<table border="1px" width="30%">
<tr>
<td> 图书名称：</td>
<td><input type="text" name="name"></td>
</tr>
<tr>
<td> 作者：</td>
<td><input type="text" name="author"></td>
</tr>
<tr>
<td> 图书价钱：</td>
<td><input type="text" name="price"></td>
</tr>
<tr>
<td>类型：</td>
<td>
<select name="category_id">
<c:forEach items="${list}" var="category">
<option value="${category.id}">${category.name}</option>
</c:forEach>
</select>
</td>
</tr>
<tr>
<td> 上传图片</td>
<td><input type="file" name="image"></td>
</tr>
<tr>
<td>详细描述</td>
<td><textarea name="description"></textarea></td>
</tr>
<tr>
<td>
<input type="submit" value="提交">
<input type="reset" value="重置">
</td>
</tr>
</table>
</form>
处理表单数据Servlet
else if (method.equals("add")) {
//上传文件和普通数据分割开，封装到Book对象上
Book book = uploadData(request);
book.setId(WebUtils.makeId());
service.addBook(book);
request.setAttribute("message", "添加图书成功");
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
- uploadData()方法代码
private Book uploadData(HttpServletRequest request) {
Book book = new Book();
try{
//1.得到解析器工厂
DiskFileItemFactory factory = new DiskFileItemFactory();
//2.得到解析器
ServletFileUpload upload = new ServletFileUpload(factory);
//设置编码
upload.setHeaderEncoding("UTF-8");
//为上传表单，则调用解析器解析上传数据
List<FileItem> list = upload.parseRequest(request); //FileItem
//遍历list，得到用于封装第一个上传输入项数据fileItem对象
for(FileItem item : list){
if(item.isFormField()){
//得到的是普通输入项
String name = item.getFieldName(); //得到输入项的名称
String value = item.getString("UTF-8");
//使用BeanUtils封装数据
BeanUtils.setProperty(book, name, value);
}else{
//得到上传输入项
//得到上传文件名全路径
String filename = item.getName();
//截取文件名
filename = filename.substring(filename.lastIndexOf("\\")+1);
InputStream in = item.getInputStream(); //得到上传数据
int len = 0;
byte buffer[]= new byte[1024];
//如果没有这个目录，就创建它
String savepath = this.getServletContext().getRealPath("/image");
File file = new File(savepath);
if (!file.exists()) {
file.mkdir();
}
FileOutputStream out = new FileOutputStream(savepath + "\\" + filename);
while((len=in.read(buffer))>0){
out.write(buffer, 0, len);
}
//设置图片的名字
book.setImage(filename);
in.close();
out.close();
//关闭临时文件
item.delete();
}
}
}catch (Exception e) {
e.printStackTrace();
}
return book;
}- 效果：
后台显示图书模块
由于我们用的是分页技术，所以我们导入之前写过的Page类和jsp吧…..这些代码可以在我复用代码博文中找到
绑定超链接
<a href="${pageContext.request.contextPath}/BookServlet?method=look" target="body">查看图书</a>Servlet处理请求
else if (method.equals("look")) {
String currentPageCount = request.getParameter("currentPageCount");
Page page = service.getPageData(currentPageCount);
request.setAttribute("page",page);
request.getRequestDispatcher("/background/listBook.jsp").forward(request, response);
}显示图书JSP页面
Servlet端传过来的是Page对象，而不是list集合
可以根据记载在Book对象的图片名称，弄一个超链接，超链接指向服务端的图片，这样就可以查看图片了！
<c:if test="${empty(page.list)}">
暂时还没有任何图书哦
</c:if>
<c:if test="${!empty(page.list)}">
<table border="1px">
<tr>
<td>书名</td>
<td>作者</td>
<td>价钱</td>
<td>描述</td>
<td>图片</td>
<td>操作</td>
</tr>
<c:forEach var="book" items="${page.list}" >
<tr>
<td>${book.name}</td>
<td>${book.author}</td>
<td>${book.price}</td>
<td>${book.description}</td>
<td><a href="${pageContext.request.contextPath}/image/${book.image}">查看图片</a></td>
<td>
<a href="#">删除</a>
<a href="#">修改</a>
</td>
</tr>
</c:forEach>
</table>
<br>
<jsp:include page="page.jsp"/>
</c:if>
效果：
前台页面
看回我们前台页面的成果图，我们可以把整个body页面看成是三个div
- body占整个div
- 导航条是一个div
- 显示图书的地方是一个div
设计好大概的布局
- html代码引入css
<link rel="stylesheet" href="body.css" type="text/css">- HTML三个div
<div id="body">
<div id="category">
<c:forEach items="${categorys}" var="category">
</c:forEach>
这是导航条
</div>
<div id="bookandpages">
<div id="books">
这是书籍的地方
</div>
<div id="page">
这是页码
</div>
</div>
</div>- CSS代码：
#body {
position: relative;
}
#category {
border: 1px solid #000;
position: absolute;
width: 300px;
height: 400px;
float: left;
left: 200px;
top: 70px;;
}
#bookandpages {
border: 1px solid #000000;
position: absolute;
width: 600px;
height: 600px;;
float: left;
left: 500px;
margin-left: 50px;
}
#books {
border: 1px solid #000;
width: 600px;
height: 550px;;
}
#page {
border: 1px solid #000;
position: absolute;
height: 48px;
width: 600px;
}
- 大概的布局
IndexServlet
在显示首页的下部分的时候，应该先去寻找一个Servlet来把数据交给对应的JSP。
如果直接显示JSP页面，是没有后台的数据的！
<frame src="${pageContext.request.contextPath}/IndexServlet"/>- Servlet代码：
//得到所有的分类数据，给body页面
BussinessServiceImpl service = new BussinessServiceImpl();
List<Category> categories = service.getAllCategory();
request.setAttribute("categories", categories);
String currentPageCount = request.getParameter("currentPageCount");
//得到所有分类的图书，给body页面
Page page = service.getPageData(currentPageCount);
request.setAttribute("page", page);
request.getRequestDispatcher("/client/body.jsp").forward(request,response);JSP显示数据
<div id="body">
<div id="category">
书籍分类 :
<br>
<c:forEach items="${categories}" var="categories">
<li>
<a href="${pageContext.request.contextPath}/ListBookServlet?category_id=${categories.id}">${categories.name}</a>
</li>
</c:forEach>
</div>
<div id="bookandpages">
<c:forEach items="${page.list}" var="book">
<div id="books">
<div id="image">
<img src="${pageContext.request.contextPath}/image/${book.image}" width="83px" height="118px">
</div>
<div id="bookinfo">
<li>
书名：${book.name}
</li>
<li>价格：${book.price}</li>
<li>作者：${book.author}</li>
</div>
</div>
<%--这里要清除浮动，十分重要！--%>
<div style="clear: both"></div>
</c:forEach>
</div>
<div id="page">
<jsp:include page="/client/page.jsp"/>
</div>
</div>
CSS代码：
重要的是：如果div浮动都黏贴在一起了，那么在后边多加个div，用于清除浮动效果
#body {
position: relative;
}
#category {
border: 1px solid #000;
position: absolute;
width: 300px;
height: 400px;
float: left;
left: 200px;
top: 70px;;
}
#bookandpages {
border: 1px solid #000000;
position: absolute;
width: 780px;
height: 538px;;
float: left;
left: 500px;
margin-left: 50px;
}
#books{
margin-left: 50px;
margin-top: 30px;
}
#image{
float: left;
}
#bookinfo{
float: left;
}
#page {
height: 62px;
width: 780px;
position: fixed;
margin-left: 549px;
margin-top: 477px;
text-align: center;
line-height: 50px;
}- 效果：
按照分类显示图书
我们可以根据左边的导航条来显示相对应的分类图书。
- Servlet代码：
BussinessServiceImpl service = new BussinessServiceImpl();
String currentPageCount = request.getParameter("currentPageCount");
String category_id = request.getParameter("category_id");
Page page = service.getPageData(currentPageCount, category_id);
List<Category> categories = service.getAllCategory();
request.setAttribute("page", page);
request.setAttribute("categories", categories);
request.getRequestDispatcher("/client/body.jsp").forward(request,response);