bookStore第二篇【圖書模塊、前臺頁面】

時間 2019-11-21

原文原文鏈接

圖書模塊

分析

在設計圖書管理的時候，咱們應該想到：圖書和分類是有關係的。一個分類能夠對應多本圖書。css

爲何要這樣設計？這樣更加人性化，用戶在購買書籍的時候，用戶可以查看相關分類後的圖書，而不是所有圖書都顯示給用戶，讓用戶一個一個去找。html

設計實體

private String id;
    private String name;
    private String author;
    private String description;
    private double price;

    //記住圖片的名稱
    private String image;

    //記住分類的id
    private String category_id;

    //各類setter和getter

設計數據庫表

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) );

編寫DAO

/** * 圖書模塊 * 1：添加圖書 * 2：查看圖書 * 3：查找圖書的分頁數據【圖書通常來講有不少，因此要分頁】 */ 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); } } /**獲得圖書的分頁數據*/ 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); } } /**獲得按照分類圖書的分頁數據*/ public List<Book> getPageData(int start, int end,String category_id) { QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource()); //WHERE字句在limit字句的前邊，注意Object[]的參數位置！ 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); } } /** * 獲得圖書的總記錄數 */ 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); } } /** * 獲得分類後圖書的總記錄數 * 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); } } }

測試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("這是一本好書");
        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);
}

編寫Service層

/*添加圖書*/
    public void addBook(Book book) {
        bookDao.addBook(book);

    }

    /*查找圖書*/
    public Book findBook(String id) {
        return bookDao.findBook(id);
    }

    /*查找圖書*/
    public Book findBook(String id) {
        return bookDao.findBook(id);
    }

    /*獲取圖書的分頁數據*/
    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;

    }

    /*獲取圖書分類後的分頁數據*/
    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;

    }

後臺添加圖書

後臺要添加圖書的時候，應該說明圖書的類型是什麼。sql

要想在顯示添加圖書的頁面上知道所有類型的id，就要通過Servlet把類型的集合傳送過去數據庫

綁定連接

<a href="${pageContext.request.contextPath}/BookServlet?method=addUI" target="body">添加圖書</a><br>

傳送類型集合的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); }

顯示JSP頁面

<form action="${pageContext.request.contextPath}/BookServlet?method=add" method="post" enctype="multipart/form-data">

    <table border="1px" width="30%">
        <tr>
            <td> 圖書名稱：</td>
            <td><input type="text" name="name"></td>
        </tr>
        <tr>
            <td> 做者：</td>
            <td><input type="text" name="author"></td>
        </tr>
        <tr>
            <td> 圖書價錢：</td>
            <td><input type="text" name="price"></td>
        </tr>
        <tr>
            <td>類型：</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> 上傳圖片</td>
            <td><input type="file" name="image"></td>
        </tr>
        <tr>
            <td>詳細描述</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>

處理表單數據Servlet

else if (method.equals("add")) { //上傳文件和普通數據分割開，封裝到Book對象上 Book book = uploadData(request); book.setId(WebUtils.makeId()); service.addBook(book); request.setAttribute("message", "添加圖書成功"); request.getRequestDispatcher("/message.jsp").forward(request, response); }

uploadData()方法代碼

private Book uploadData(HttpServletRequest request) {

        Book book = new Book();
        try{

            //1.獲得解析器工廠
            DiskFileItemFactory factory = new DiskFileItemFactory();

            //2.獲得解析器
            ServletFileUpload upload = new ServletFileUpload(factory);

            //設置編碼
            upload.setHeaderEncoding("UTF-8");


            //爲上傳表單，則調用解析器解析上傳數據
            List<FileItem> list = upload.parseRequest(request);  //FileItem

            //遍歷list，獲得用於封裝第一個上傳輸入項數據fileItem對象
            for(FileItem item : list){

                if(item.isFormField()){

                    //獲得的是普通輸入項
                    String name = item.getFieldName();  //獲得輸入項的名稱
                    String value = item.getString("UTF-8");

                    //使用BeanUtils封裝數據
                    BeanUtils.setProperty(book, name, value);
                }else{

                    //獲得上傳輸入項

                    //獲得上傳文件名全路徑
                    String filename = item.getName();

                    //截取文件名
                    filename = filename.substring(filename.lastIndexOf("\\")+1);

                    InputStream in = item.getInputStream();   //獲得上傳數據

                    int len = 0;
                    byte buffer[]= new byte[1024];

                    //若是沒有這個目錄，就建立它
                    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);
                    }
                    //設置圖片的名字
                    book.setImage(filename);

                    in.close();
                    out.close();

                    //關閉臨時文件
                    item.delete();
                }
            }

        }catch (Exception e) {
            e.printStackTrace();
        }
        return book;
    }

效果：

後臺顯示圖書模塊

因爲咱們用的是分頁技術，因此咱們導入以前寫過的Page類和jsp吧…..這些代碼能夠在我複用代碼博文中找到bash

綁定超連接

<a href="${pageContext.request.contextPath}/BookServlet?method=look" target="body">查看圖書</a>

Servlet處理請求

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); }

顯示圖書JSP頁面

Servlet端傳過來的是Page對象，而不是list集合markdown

能夠根據記載在Book對象的圖片名稱，弄一個超連接，超連接指向服務端的圖片，這樣就能夠查看圖片了！app

<c:if test="${empty(page.list)}"> 暫時尚未任何圖書哦 </c:if> <c:if test="${!empty(page.list)}"> <table border="1px"> <tr> <td>書名</td> <td>做者</td> <td>價錢</td> <td>描述</td> <td>圖片</td> <td>操做</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}">查看圖片</a></td> <td> <a href="#">刪除</a> <a href="#">修改</a> </td> </tr> </c:forEach> </table> <br> <jsp:include page="page.jsp"/> </c:if>

效果：

前臺頁面

看回咱們前臺頁面的成果圖，咱們能夠把整個body頁面當作是三個divjsp

body佔整個div
導航條是一個div
顯示圖書的地方是一個div

設計好大概的佈局

html代碼引入css

<link rel="stylesheet" href="body.css" type="text/css">

HTML三個div

<div id="body">
    <div id="category">
        <c:forEach items="${categorys}" var="category">

        </c:forEach>

        這是導航條
    </div>

    <div id="bookandpages">
        <div id="books">
            這是書籍的地方

        </div>

        <div id="page">
            這是頁碼
        </div>
    </div>

</div>

CSS代碼：

#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; }

大概的佈局

IndexServlet

在顯示首頁的下部分的時候，應該先去尋找一個Servlet來把數據交給對應的JSP。佈局

若是直接顯示JSP頁面，是沒有後臺的數據的！post

<frame src="${pageContext.request.contextPath}/IndexServlet"/>

Servlet代碼：

//獲得全部的分類數據，給body頁面
        BussinessServiceImpl service = new BussinessServiceImpl();
        List<Category> categories = service.getAllCategory();
        request.setAttribute("categories", categories);
        String currentPageCount = request.getParameter("currentPageCount");

        //獲得全部分類的圖書，給body頁面
        Page page = service.getPageData(currentPageCount);
        request.setAttribute("page", page);

        request.getRequestDispatcher("/client/body.jsp").forward(request,response);

JSP顯示數據

<div id="body">
    <div id="category">
        書籍分類 :
        <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>
                        書名：${book.name}
                    </li>
                    <li>價格：${book.price}</li>
                    <li>做者：${book.author}</li>
                </div>


        </div>
            <%--這裏要清除浮動，十分重要！--%>
            <div style="clear: both"></div>
        </c:forEach>

    </div>
    <div id="page">
        <jsp:include page="/client/page.jsp"/>
    </div>
</div>

CSS代碼：

重要的是：若是div浮動都黏貼在一塊兒了，那麼在後邊多加個div，用於清除浮動效果

#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：

按照分類顯示圖書

咱們能夠根據左邊的導航條來顯示相對應的分類圖書。

Servlet代碼：

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);