bookStore第二篇【图书模块、前台页面】

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：

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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：

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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);

效果：

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