[学习笔记]jsp+javaBean+Servlet 的设计模式MVC 的实例

最新推荐文章于 2021-03-04 20:26:47 发布

lovejavalovejava

最新推荐文章于 2021-03-04 20:26:47 发布

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CC 4.0 BY-SA版权

文章标签： jsp 设计模式 servlet null 数据库 jdbc

本文链接：https://blog.youkuaiyun.com/lovejavalovejava/article/details/2305960

//运行结果后显示页面

<%@page import="cn.java.BookBean"%>

<html>

<head>

</head>

<body>

<jsp:useBean id="bookBean" type="cn.java.BookBean" scope="request"></jsp:useBean>

<ul>

</ul>

</body>

</html>

//javaBean 程序

package cn.java;

public class BookBean {

//ISBN ��

private String isbn;

//��

private String title;

//��

private String author;

//��

private String publisher;

//�۸�

private int price;

public BookBean(){

}

public BookBean(String isbn,String title,String autor,String publisher,int price){

this.isbn=isbn;

this.title=title;

this.author=author;

this.publisher=publisher;

this.price=price;

}

public String getAuthor() {

return author;

}

public void setAuthor(String author) {

this.author = author;

}

public String getIsbn() {

return isbn;

}

public void setIsbn(String isbn) {

this.isbn = isbn;

}

public int getPrice() {

return price;

}

public void setPrice(int price) {

this.price = price;

}

public String getPublisher() {

return publisher;

}

public void setPublisher(String publisher) {

this.publisher = publisher;

}

public String getTitle() {

return title;

}

public void setTitle(String title) {

this.title = title;

}

//Serlvet 程序

import cn.java.BookBean;

import cn.java.DBUtil;

import java.io.IOException;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class QueryBookServlet extends HttpServlet{

/**

@Override

public void doGet(HttpServletRequest request,

HttpServletResponse response)throws ServletException,IOException{

final String SQL ="select * from BookList where isbn=?";

Connection conn=null;

PreparedStatement stmt=null;

ResultSet rs=null;

String address="unknownBook.jsp";

//��javaBean ��

BookBean book=new BookBean();

try{

//��ݿ�l��

conn=DBUtil.getConnection();

stmt=conn.prepareStatement(SQL);

//ָ��

stmt.setString(1,request.getParameter("isbn"));

//ִ�� ѯ

rs=stmt.executeQuery();

if(rs!=null){

rs.next();

book.setIsbn(rs.getString("isbn"));

book.setTitle(rs.getString("title"));

book.setAuthor(rs.getString("author"));

book.setPublisher(rs.getString("publisher"));

book.setPrice(rs.getInt("price"));

address="displayBook.jsp";

}

}catch(SQLException e){

e.printStackTrace();

}

//��

DBUtil.closeResultSet(rs);

DBUtil.closeStatement(stmt);

DBUtil.closeConnection(conn);

request.setAttribute("bookBean",book);

//��ת��jspҳ��

RequestDispatcher dis=request.getRequestDispatcher(address);

dis.forward(request,response);

}

//数据库连接

package cn.java;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.logging.Level;

import java.util.logging.Logger;

public class DBUtil {

static String serverName="localhost";

static String sDBDriver="com.mysql.jdbc.Driver";

static String url="jdbc:mysql://127.0.0.1/test";

static String dbUser="root";

static String dbPwd="root";

/**

* �õ�һ��Connection

* */

public static Connection getConnection(){

Connection conn=null;

try {

Class.forName(sDBDriver);

conn=DriverManager.getConnection(url, dbUser,dbPwd);

} catch (SQLException ex) {

Logger.getLogger(DBUtil.class.getName()).log(Level.SEVERE, null, ex);

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return conn;

}

/**

* �ر�ָ��Ľ��

* @param rs Ҫ�رյĽ��

* */

public static void closeResultSet(ResultSet rs){

if(rs!=null){

try{

rs.close();

}catch(SQLException e){

e.printStackTrace();

}

public static void closeStatement(Statement stmt){

if(stmt!=null){

try {

stmt.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

public static void closeConnection(Connection conn){

if(conn!=null){

try {

conn.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

public static void main(String args[]){

System.out.println(getConnection());

}

//运行首页

<html>

<title>

isbn

</title>

<body>

</form>

</body>

</html>

//数据库表建立

create table BookList(

isbn varchar(30) primary key,

title varchar(30) not null,

author varchar(30) not null,

publisher varchar(30) not null,

price int(4)

);