java web 学习 --第十天（Java三级考试）

第九天学习内容：http://www.cnblogs.com/tobecrazy/p/3470195.html

需求概述

创建程序模块，读取并显示数据库中的书籍信息。当前有如下需求：需要显示数据库中所有登记的书籍信息，需要显示的字段信息包括ISBN、title、copyright、editionNumber、price。数据保存在数据库中，数据表名称为：tbl_books。编写程序实现该需求。

实现说明

1）采用MVC设计模式， 在JSP页面（listbook.jsp）中显示所有图书；

2）采用自定义标签技术，实现图书列表的显示；

3）创建JAVABEAN作为业务逻辑类，访问数据库资源；

4）数据库配置信息的管理，如：驱动名称，连接字符串，用户名，密码必须从配置文件中读取。

首先创建表，并插入数据：

/*
MySQL Data Transfer
Source Host: localhost
Source Database: test
Target Host: localhost
Target Database: test
Date: 2010-10-13 15:26:26
*/

SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for tbl_books
-- ----------------------------
CREATE TABLE `tbl_books` (
  `isbn` varchar(20) NOT NULL,
  `title` varchar(100) NOT NULL,
  `editionNumber` int(11) NOT NULL,
  `copyright` varchar(4) NOT NULL,
  `publisherID` int(11) NOT NULL,
  `imageFile` varchar(20) NOT NULL,
  `price` double NOT NULL,
  PRIMARY KEY  (`isbn`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records
-- ----------------------------
INSERT INTO `tbl_books` VALUES ('', 'Java How to Program (Java 2)', '', '', '', 'jhtp3.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'Internet and World Wide Web How \r\n\r\nto Program', '', '', '', 'iw3htp1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'XML How to Program', '', '', '', 'xmlhtp1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'Perl How to Program', '', '', '', 'perlhtp1.jpg', '');
INSERT INTO `tbl_books` VALUES ('013028419x', 'e-Business and e-Commerce How to \r\n\r\nProgram', '', '', '', 'ebechtp1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'The Complete Java Training Course \r\n\r\n(Java 1.1)', '', '', '', 'javactc2.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'The Complete Visual Basic 6 \r\n\r\nTraining Course', '', '', '', 'vbctc1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'The Complete Java 2 Training \r\n\r\nCourse', '', '', '', 'javactc3.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'The Complete Internet and World \r\n\r\nWide Web Programming Training Course', '', '', '', 'iw3ctc1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'Advanced Java 2 Platform How to \r\n\r\nProgram', '', '', '', 'advjhtp1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'C++ How to Program', '', '', '', 'cpphtp3.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'C How to Program', '', '', '', 'chtp3.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'C How to Program', '', '', '', 'chtp2.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'Visual Basic 6 How to Program', '', '', '', 'vbhtp1.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'C++ How to Program', '', '', '', 'cpphtp2.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'Java How to Program (Java 1.1)', '', '', '', 'jhtp2.jpg', '');
INSERT INTO `tbl_books` VALUES ('', 'The Complete C++ Training Course', '', '', '', 'cppctc3.jpg', '');

创建一个web project

添加一个Servlet，命名为BookAction

package com.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.service.BookService;

public class BookAction extends HttpServlet {

    /**
     * Constructor of the object.
     */
    public BookAction() {
        super();
    }

    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doPost(request,response);

        /*response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out
                .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<HTML>");
        out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println("  <BODY>");
        out.print("    This is ");
        out.print(this.getClass());
        out.println(", using the GET method");
        out.println("  </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();*/
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        BookService bookservice=new BookService();
        List booklist=bookservice.getBookList();
        request.getSession().setAttribute("booklist", booklist);
        request.getRequestDispatcher("listbook.jsp").forward(request, response);

        /*response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out
                .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<HTML>");
        out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println("  <BODY>");
        out.print("    This is ");
        out.print(this.getClass());
        out.println(", using the POST method");
        out.println("  </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();*/
    }

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
        // Put your code here
    }

}

创建book 类，生成get/set method

ackage bookpojo;

public class Book {

    private String isbn;
    private String title;
    private double price;
    public String getIsbn() {
        return isbn;
    }
    public void setIsbn(String isbn) {
        this.isbn = isbn;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }

}

创建一个bookservice 类，使用properties拿到数据库相关配置，之后把查询结果放到List中

package com.service;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import bookpojo.Book;

public class BookService {
    static  String driver ;//="com.mysql.jdbc.Driver";
    static  String url;//="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8";
    static  String user;//="root";
    static  String password;//="3edc4rfv";
    public BookService()
    {
        try{
            Properties p=new Properties();
            p.load(this.getClass().getResourceAsStream("db.properties"));
            driver=p.getProperty("driver");
            url=p.getProperty("url");
            user=p.getProperty("username");
            password=p.getProperty("password");
            System.out.println(driver+url+user+password);
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    public List getBookList()
    {
        List list=new ArrayList();
        try{
            Class.forName(driver);
            Connection con= DriverManager.getConnection(url,user,password);
            Statement stmt=con.createStatement();
            java.sql.ResultSet rs=stmt.executeQuery("select * from tbl_books;");
            while(rs.next())
            {
                Book book=new Book();
                book.setIsbn(rs.getString("isbn"));
                book.setPrice(rs.getDouble("price"));
                book.setTitle(rs.getString("title"));
                list.add(book);

            }

            rs.close();
            con.close();

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

        return  list;

    }

}

创建一个BookTagHandle继承 SimpleTagSupport

package com.tag;

import java.io.IOException;
import java.util.List;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.SimpleTagSupport;

import bookpojo.Book;

public class BookTagHandle extends SimpleTagSupport {

    @Override
    public void doTag() throws JspException, IOException {
        // TODO Auto-generated method stub
        JspWriter out=this.getJspContext().getOut();
        List<Book> list=(List<Book>) this.getJspContext().findAttribute("booklist");
        for(Book o:list)
        {
           out.print(o.getIsbn()+"\t"+o.getTitle()+"\t"+o.getPrice()+"<br>");
        }

    }

}

将mysql-connector5.0-bin.jar放在WebRoot/WEB-INF/lib目录下

将自定义标签放在WebRoot/WEB-INF，名字为book.tld

<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE taglib
  PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN"
  "http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
<taglib>
  <tlibversion>1.0</tlibversion>
  <jspversion>1.1</jspversion>
  <shortname>Application Tag Library</shortname>
  <uri>http://jakarta.apache.org/taglibs/struts-example-1.0</uri>
  <info></info>

  <tag>
    <name>display</name>
    <tagclass>com.tag.BookTagHandle</tagclass>
    <bodycontent>empty</bodycontent>
    <info></info>

  </tag>

</taglib>

在booklist.jsp页面添加

<%@ taglib uri="WEB-INF/book.tld" prefix="book" %> 

在body标签添加

<td width="695">
                    <table>
                        <tr>
                            <td width="3%">
                                &nbsp;
                            </td>
                            <td width="97%">
                                <table width="688">
                                    <tr>
                                        <TD width='20%' height="30" align='center'>
                                            ISBN
                                        </TD>
                                        <TD width='40%' align='center'>
                                            TITLE
                                        </TD>

                                        <TD align='center' width="20%">
                                            PRICE
                                        </TD>
                                    </tr>
                                    <tr>
                                        <td colspan='5'>
                                        <book:display/>
                                        </td>
                                    </tr>

大功告成