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 ('0130125075', 'Java How to Program (Java 2)', '3', '2000', '1', 'jhtp3.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0130161438', 'Internet and World Wide Web How \r\n\r\nto Program', '1', '2000', '1', 'iw3htp1.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0130284173', 'XML How to Program', '1', '2001', '1', 'xmlhtp1.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0130284181', 'Perl How to Program', '1', '2001', '1', 'perlhtp1.jpg', '70'); INSERT INTO `tbl_books` VALUES ('013028419x', 'e-Business and e-Commerce How to \r\n\r\nProgram', '1', '2001', '1', 'ebechtp1.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0130829277', 'The Complete Java Training Course \r\n\r\n(Java 1.1)', '2', '1998', '2', 'javactc2.jpg', '100'); INSERT INTO `tbl_books` VALUES ('0130829293', 'The Complete Visual Basic 6 \r\n\r\nTraining Course', '1', '1999', '2', 'vbctc1.jpg', '110'); INSERT INTO `tbl_books` VALUES ('0130852473', 'The Complete Java 2 Training \r\n\r\nCourse', '3', '2000', '2', 'javactc3.jpg', '110'); INSERT INTO `tbl_books` VALUES ('0130856118', 'The Complete Internet and World \r\n\r\nWide Web Programming Training Course', '1', '2000', '2', 'iw3ctc1.jpg', '110'); INSERT INTO `tbl_books` VALUES ('0130895601', 'Advanced Java 2 Platform How to \r\n\r\nProgram', '1', '2002', '1', 'advjhtp1.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0130895717', 'C++ How to Program', '3', '2001', '1', 'cpphtp3.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0130895725', 'C How to Program', '3', '2001', '1', 'chtp3.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0132261197', 'C How to Program', '2', '1994', '1', 'chtp2.jpg', '50'); INSERT INTO `tbl_books` VALUES ('0134569555', 'Visual Basic 6 How to Program', '1', '1999', '1', 'vbhtp1.jpg', '70'); INSERT INTO `tbl_books` VALUES ('0135289106', 'C++ How to Program', '2', '1998', '1', 'cpphtp2.jpg', '50'); INSERT INTO `tbl_books` VALUES ('0138993947', 'Java How to Program (Java 1.1)', '2', '1998', '1', 'jhtp2.jpg', '50'); INSERT INTO `tbl_books` VALUES ('0139163050', 'The Complete C++ Training Course', '3', '2001', '2', 'cppctc3.jpg', '110');
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%"> </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
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