软件工程概论课后作业01

1. 网站系统开发需要掌握的技术

①java语言

Java语言体系比较庞大，包括多个模块。从WEB项目应用角度讲有JSP，Servlet，JDBC，JavaBean（Application）四部分技术。JDBC可做三件事情：与数据库建立连接，发送SQL语句，处理结果。Servlet从客户端（通过WEB服务器）接受请求，执行某种操作，然后返回结果。JSP是从Servlet上分离出来的一小部分，简化了开发，加强了页面设计。JavaBean能提供常用功能并且可以重复使用，这使得开发人员可以把某些关键功能和核心算法提取出来封装成为一个组件对象，这样就增加了代码的重用率和系统的安全性。

②面向对象分析设计思想

Java语言是完全面向对象的语言，所以在项目设计时会有很大的帮助，在设计时应尽量舍弃以往的面向过程的设计方式。

③设计模式和构架结构

设计模式在java项目实施过程更是重中之重。主要在与两层的设计模式，三层的设计模式和N层的设计模式。它直接决定着项目的应用，部署和实际开发设计。

④XML语言

在服务器和设计模式结构中会应用到自定义文件，而且在应用高级设计时也会定义自用的标签，现在流行的是用XML去定义配置，所以XML语言应该有一定掌握。XML大致可以分为3类，分别是简单数据的表示和交换，面向消息的计算，用户界面相关。

⑤网页脚本语言

网页脚本语言的执行都是在客户端执行的，速度很快，并且大多数的操作与服务器没有交互计算，所以在一些应用中非常理想。在设计WEB项目的应用中，网页的脚本语言起着不能忽视的作用，对JAVAScript应有一定的了解。

⑥开发工具

数据库，Web服务器，集成开发环境

2.源代码

package com.jaovo.msg.dao;
import java.util.List;
import com.jaovo.msg.model.User;
public interface IUserDao {public void add(User user);public void delete(int id);public void update(User user);public User load(int id);public User load(String username);public List<User> load();
}

package com.jaovo.msg.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;import com.jaovo.msg.Util.DBUtil;
import com.jaovo.msg.Util.UserException;
import com.jaovo.msg.model.User;import sun.net.www.content.text.plain;public class UserDaoImpl implements IUserDao {@Overridepublic void add(User user) {//获得链接对象Connection connection = DBUtil.getConnection();//准备sql语句String sql = "select count(*) from t_user where username = ?";//创建语句传输对象PreparedStatement preparedStatement = null;ResultSet resultSet = null;try {preparedStatement = connection.prepareStatement(sql);preparedStatement.setString(1, user.getUsername());//接收结果集resultSet = preparedStatement.executeQuery();//遍历结果集while(resultSet.next()) {if (resultSet.getInt(1) > 0) {throw new UserException("用户已存在") ;}}sql = "insert into t_user(username,password,nickname) value (?,?,?)";preparedStatement = connection.prepareStatement(sql);preparedStatement.setString(1, user.getUsername());preparedStatement.setString(2, user.getPassword());preparedStatement.setString(3, user.getNickname());preparedStatement.executeUpdate();} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}finally {//关闭资源
            DBUtil.close(resultSet);DBUtil.close(preparedStatement);DBUtil.close(connection);}}@Overridepublic void delete(int id) {Connection connection = DBUtil.getConnection();String sql = "delete from t_user where id = ?";PreparedStatement preparedStatement = null;try {preparedStatement = connection.prepareStatement(sql);preparedStatement.setInt(1, id);preparedStatement.executeUpdate();} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}finally {DBUtil.close(preparedStatement);DBUtil.close(connection);}}@Overridepublic void update(User user) {Connection connection = DBUtil.getConnection();//准备sql语句String sql = "update t_user set password = ? , nickname=? where id = ?";//创建语句传输对象PreparedStatement preparedStatement = null;try {preparedStatement = connection.prepareStatement(sql);preparedStatement.setString(1, user.getPassword());preparedStatement.setString(2, user.getNickname());preparedStatement.setInt(3, user.getId());preparedStatement.executeUpdate();} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}finally {DBUtil.close(preparedStatement);DBUtil.close(connection);}}@Overridepublic User load(int id) {Connection connection = DBUtil.getConnection();//准备sql语句String sql = "select * from t_user  where id = ?";//创建语句传输对象PreparedStatement preparedStatement = null;ResultSet resultSet = null;User user = null;try {preparedStatement = connection.prepareStatement(sql);preparedStatement.setInt(1, id);resultSet = preparedStatement.executeQuery();while(resultSet.next()) {user = new User();user.setId(id);user.setUsername(resultSet.getString("username"));user.setPassword(resultSet.getString("password"));user.setNickname(resultSet.getString("nickname"));}} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}finally {DBUtil.close(resultSet);DBUtil.close(preparedStatement);DBUtil.close(connection);}return  user;}@Overridepublic User load(String username) {// TODO Auto-generated method stubreturn null;}@Overridepublic List<User> load() {Connection connection = DBUtil.getConnection();//准备sql语句String sql = "select * from t_user ";//创建语句传输对象PreparedStatement preparedStatement = null;ResultSet resultSet = null;//集合中只能放入user对象List<User> users = new ArrayList<User>();User user = null;try {preparedStatement = connection.prepareStatement(sql);resultSet = preparedStatement.executeQuery();while(resultSet.next()) {user = new User();user.setId(resultSet.getInt("id"));user.setUsername(resultSet.getString("username"));user.setPassword(resultSet.getString("password"));user.setNickname(resultSet.getString("nickname"));users.add(user);}} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}finally {DBUtil.close(resultSet);DBUtil.close(preparedStatement);DBUtil.close(connection);}return  users;}}

package com.jaovo.msg.model;public class User {private int id;private String  username;private String  nickname;private String  password;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getNickname() {return nickname;}public void setNickname(String nickname) {this.nickname = nickname;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}}

package com.jaovo.msg.Util;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class DBUtil {public  static  Connection getConnection() {try {//1 加载驱动Class.forName("com.mysql.jdbc.Driver").newInstance();} catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {// TODO Auto-generated catch block
            e.printStackTrace();}String user = "root";String password = "root";String url = "jdbc:mysql://localhost:3306/jaovo_msg";Connection connection = null;try {//2 创建链接对象connectionconnection = DriverManager.getConnection(url,user,password);} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}return connection;}//关闭资源的方法public static void close(Connection connection ) {try {if (connection != null) {connection.close();}} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}public static void close(PreparedStatement preparedStatement ) {try {if (preparedStatement != null) {preparedStatement.close();}} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}public static void close(ResultSet resultSet ) {try {if (resultSet != null) {resultSet.close();}} catch (SQLException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}}

package com.jaovo.msg.Util;public class UserException extends RuntimeException{public UserException() {super();// TODO Auto-generated constructor stub
    }public UserException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {super(message, cause, enableSuppression, writableStackTrace);// TODO Auto-generated constructor stub
    }public UserException(String message, Throwable cause) {super(message, cause);// TODO Auto-generated constructor stub
    }public UserException(String message) {super(message);// TODO Auto-generated constructor stub
    }public UserException(Throwable cause) {super(cause);// TODO Auto-generated constructor stub
    }}

<%@page import="com.jaovo.msg.Util.UserException"%>
<%@page import="com.jaovo.msg.dao.UserDaoImpl"%>
<%@page import="com.jaovo.msg.model.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<%//接收客户端传递过来的参数String username = request.getParameter("username");String password = request.getParameter("password");String nickname = request.getParameter("nickname");if(username == null || "".equals(username.trim())){request.setAttribute("error", "用户名不能为空");%><jsp:forward page="addInput.jsp"></jsp:forward>
<%}User user = new User();user.setUsername(username);user.setPassword(password);user.setNickname(nickname);UserDaoImpl userDao = new UserDaoImpl();try{userDao.add(user);//重定向response.sendRedirect("list.jsp");
%><%}catch(UserException e){
%><h2 style="color:red ; font-size:50px">发生错误 : <%=e.getMessage() %></h2><%}%>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head><title>用户添加页面</title>
</head>
<body><%=request.getAttribute("error") %><form action="add.jsp" method="get"><table align="center" border="1" width="500"><tr><td>用户名称 : </td><td><input type="text" name="username" /></td></tr><tr><td>用户密码:</td><td><input type="password" name="password" /></td></tr><tr><td>用户昵称:</td><td><input type="text" name="nickname" /></td></tr><tr align="center"><td colspan="2"><input type="submit" value="提交" /><input type="reset" value="重置" /></td></tr></table></form>
</body>
</html>

3.运行结果截图