bookStore第二篇【图书模块、前台页面】

傷城~ 2021-09-17 05:52 376阅读 0赞

# 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** ###

### **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：

![这里写图片描述][SouthEast]

--------------------

## 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** ###

### **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：** ###

![这里写图片描述][SouthEast 1]

--------------------

# 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

![这里写图片描述][SouthEast 2]

--------------------

## 设计好大概的布局 ##

*  **html代码引入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

![这里写图片描述][SouthEast 3]

--------------------

## 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！**

*  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：

![这里写图片描述][SouthEast 4]

--------------------

## 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);

### **效果：** ###

![这里写图片描述][SouthEast 5]

--------------------

[SouthEast]: /images/20210827/10f6ee6b4b72487d809113ccdcf94452.png
[SouthEast 1]: /images/20210827/73ff556330d24aafa899a577ceb3aef4.png
[SouthEast 2]: /images/20210827/5d26f8bc69ef4858b74263b1e92b2849.png
[SouthEast 3]: /images/20210827/7182e941818b4c86bf6a66dd08b28faa.png
[SouthEast 4]: /images/20210827/465cbabc4233424faef7d6a2236eb409.png
[SouthEast 5]: /images/20210827/d1a47f7f37394152a23f1c8e88ec1e63.png