JavaWeb学习-1

一，Java Web项目需要掌握的技术

　　·java语言

　　　　-|  JDBC

　　　　-|  Servlet

　　　　-|  JSP

　　　　-|  JavaBean

　　·面向对象分析设计思想

　　·设计模式和框架结构

　　·XML语言

　　·网页脚本语言

　　·开发工具

　　　　-|数据库

　　　　-|应用服务器

　　　　-|集成开发环境（IDE）

二.源代码：

package dao;

import java.util.List;

import model.*;
public interface IUserDao 
{
    public void add(User user);
    public void delete(String username);
    public void update(User user);
    public User load(int id);
    public User load(String username);
    public List<User> load();
}

package 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 Util.*;
import model.*;

public class UserDaoImpl implements IUserDao
{
    @Override
    public void add(User user) 
    {
        Connection connection=Util.getConnection();
        String sql="select count(*) from t_user where username=?";
        PreparedStatement preparedStatement=null;
        ResultSet resultSet=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getUsername());
            resultSet=preparedStatement.executeQuery();
            while(resultSet.next())
            {
                if(resultSet.getInt(1)>0)
                {
                    throw new UserException("用户已存在!");
                }
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        sql="insert into t_user(username,password) value(?,?)";
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getUsername());
            preparedStatement.setString(2, user.getPassword());
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            Util.close(connection);
            Util.close(preparedStatement);
            Util.close(resultSet);
        }
    }

    @Override
    public void delete(String username) {
        Connection connection=Util.getConnection();
        String sql="delete from t_user where username = ?";
        PreparedStatement preparedStatement=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, username);
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            Util.close(connection);
            Util.close(preparedStatement);
        }    
    }

    @Override
    public void update(User user) {
        Connection connection=Util.getConnection();
        String sql="update t_user set password = ? where username = ?";
        PreparedStatement preparedStatement=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getPassword());
            preparedStatement.setString(2, user.getUsername());
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            Util.close(connection);
            Util.close(preparedStatement);
        }
    }

    @Override
    public User load(int id) 
    {
        Connection connection=Util.getConnection();
        String sql="select * from t_user where id=?";
        User user=null;
        PreparedStatement preparedStatement=null;
        ResultSet resultSet=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"));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            Util.close(connection);
            Util.close(preparedStatement);
            Util.close(resultSet);
        }
        return user;
    }

    @Override
    public User load(String username) 
    {
        Connection connection=Util.getConnection();
        String sql="select * from t_user where username=?";
        User user=null;
        PreparedStatement preparedStatement=null;
        ResultSet resultSet=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, username);
            resultSet=preparedStatement.executeQuery();
            while(resultSet.next())
            {
                user=new User();
                user.setId(resultSet.getInt("id"));
                user.setUsername(username);
                user.setPassword(resultSet.getString("password"));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            Util.close(connection);
            Util.close(preparedStatement);
            Util.close(resultSet);
        }
        return user;
    }

    @Override
    public List<User> load() 
    {
        Connection connection=Util.getConnection();
        String sql="select * from t_user ";
        PreparedStatement preparedStatement=null;
        ResultSet resultSet=null;
        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"));
                users.add(user);
            }
        }catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            Util.close(connection);
            Util.close(preparedStatement);
            Util.close(resultSet);
        }
        return users;
        }
}

package model;

public class User 
{
    private int id;
    private String username;
    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 getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }

}

package model;

public class UserException extends RuntimeException{

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    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="dao.UserDaoImpl"%>
<%@page import="model.*"%>
<%@page import="Util.*"%>
<%@ 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<%
    String username=request.getParameter("username");
    String password=request.getParameter("password");
    String repassword=request.getParameter("repassword");
    if(username==null||"".equals(username.trim()))
    {
        request.setAttribute("error","用户名不能为空！");
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%
    }
    if(password==null||"".equals(password.trim()))
    {
        request.setAttribute("error","密码不能为空！");
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%
    }
    if(repassword==null||"".equals(repassword.trim()))
    {
        request.setAttribute("error","再次输入密码以示确认！");
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%
    }
    if(!password.trim().equals(repassword.trim()))
    {
        request.setAttribute("error","两次输入的密码不一致。请确认后再进行操作！");
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%
    }
    User user=new User();
    user.setUsername(username);
    user.setPassword(password);
    UserDaoImpl userDao=new UserDaoImpl();
    try
    {
    userDao.add(user);
%>
    <h2 style="color:blue">用户保存成功！</h2>
<%
    }catch(UserException e)
    {
%>
    <h2 style="color:red">error:<%=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>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>用户注册</title>
</head>
<body>
    <form action="add.jsp" method="get">
        <table align="center" border="2" width="500">
            <tr>
            <td>用户名：</td>
            <td>
                <input type="text" name="username" />
            </td>
            </tr>
            <tr>
            <td>密码：</td>
            <td>
                <input type="password" name="password" />
            </td>
            </tr>
            <tr>
            <td>确认密码：</td>
            <td>
                <input type="password" name="repassword" />
            </td>
            </tr>
            <tr align="center">
            <td colspan="2">
                <input type="submit" value="提交" />
                <input type="reset" value="重置" />
            </td>
            </tr>
        </table>
    </form>
    <br>
    <%
    if(request.getAttribute("error")!=null)
    {
    %>
    <h2 align="center" style="color:red"><%=request.getAttribute("error") %></h2>
    <%
    }
    %>
</body>
</html>

<%@page import="dao.*"%>
<%@page import="model.*"%>
<%@page import="Util.*"%>
<%@ 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<%
    String username=request.getParameter("username");
    String password=request.getParameter("password");
    UserDaoImpl userDao=new UserDaoImpl();
    User user=null;
    user=userDao.load(username);    
    if(user==null)
    {
        request.setAttribute("error", "您要删除的用户不存在");
%>
<jsp:forward page="deleteInput.jsp"></jsp:forward>
<%
    }
    if(!user.getPassword().equals(password))
    {
        request.setAttribute("error", "您输入的密码不正确，无权删除该用户！");
%>
<jsp:forward page="deleteInput.jsp"></jsp:forward>
<%
    }
    userDao.delete(username);
    %>
    <h2 align="center" style="color:blue">学号为<%=user.getUsername() %>的用户已经被删除！</h2><br>
</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>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>用户删除</title>
</head>
<body>
    <form action="delete.jsp" method="get">
        <table align="center" border="2" width="500">
            <tr>
            <td>请输入要删除的用户名：</td>
            <td>
                <input type="text" name="username" />
            </td>
            </tr>
            <tr>
            <td>该用户的密码为：</td>
            <td>
                <input type="password" name="password" />
            </td>
            </tr>
            <tr align="center">
            <td colspan="2">
                <input type="submit" value="删除" />
            </td>
            </tr>
        </table>
    </form>
    <br>
    <%
    if(request.getAttribute("error")!=null)
    {
    %>
    <h2 align="center" style="color:red"><%=request.getAttribute("error") %></h2>
    <%
    }
    %>
</body>
</html>

<%@page import="dao.*"%>
<%@page import="model.*"%>
<%@page import="Util.*"%>
<%@ 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<%    
    String username=request.getParameter("username");
    String password=request.getParameter("password");
    if(username==null||"".equals(username.trim()))
    {
        request.setAttribute("error","用户名不能为空！");
%>
    <jsp:forward page="dengluInput.jsp"></jsp:forward>
<%
    }
    if(password==null||"".equals(password.trim()))
    {
        request.setAttribute("error","密码不能为空！");
%>
    <jsp:forward page="dengluInput.jsp"></jsp:forward>
<%
    }
    User user=null;
    UserDaoImpl userDao=new UserDaoImpl();
    user = userDao.load(username);
    if(user==null)
    {
        request.setAttribute("error","该用户名不存在！");
%>
    <jsp:forward page="dengluInput.jsp"></jsp:forward>
<%
    }
    if(!password.equals(user.getPassword()))
    {
        request.setAttribute("error","密码错误！");
%>
    <jsp:forward page="dengluInput.jsp"></jsp:forward>
<%
    }
    else
    {
%>
    <h2 align="center" style="color:blue">登录成功！</h2>
    <a href="addInput.jsp">用户注册</a>
    <a href="deleteInput.jsp">删除用户</a>
    <a href="updateInput.jsp">修改密码</a>
    <a href="selectInput.jsp">查询用户</a>
<%
    }
%>
</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>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>登录</title>
</head>
<body>
  <form action="denglu.jsp" method="get">
        <table align="center" border="2" width="500">
            <tr>
            <td>用户名：</td>
            <td>
                <input type="text" name="username" />
            </td>
            </tr>
            <tr>
            <td>密码：</td>
            <td>
                <input type="password" name="password" />
            </td>
            <td>
                <a href="updateInput.jsp">修改密码</a>
            </td>
            </tr>
            <tr align="center">
            <td colspan="2">
                <input type="submit" value="登录" />
            </td>
            </tr>
        </table>
  </form>
  <br>
  <%
    if(request.getAttribute("error")!=null)
    {
    %>
    <h2 align="center" style="color:red"><%=request.getAttribute("error") %></h2>
    <%
    }
    %>
</body>
</html>

<%@page import="dao.*"%>
<%@page import="model.*"%>
<%@page import="Util.*"%>
<%@ 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>搜索</title>
</head>
<%
    String username=request.getParameter("username");
    if(username==null||"".equals(username.trim()))
    {
        request.setAttribute("error", "查询内容不能为空！");
%>
    <jsp:forward page="selectInput.jsp"></jsp:forward>
<%
    }
    User user=null;
    UserDaoImpl userDao=new UserDaoImpl();
    user=userDao.load(username);
    if(user==null)
    {
        request.setAttribute("error", "您查找的用户不存在！");
%>
    <jsp:forward page="selectInput.jsp"></jsp:forward>
<%
    }
    else
    {
%>
    <h2 align="center" style="color:blue">查询结果为：编号:<%=user.getId() %>学号：<%=user.getUsername() %>密码：<%=user.getPassword() %></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>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>用户搜索</title>
</head>
    <form action="select.jsp" method="get">
      <table align="center" border="2" width="500">
      <tr>
      <td>请输入您要搜索的用户名：</td>
      <td>
          <input type="text" name="username" />
      </td>    
      </tr>
      <tr align="center">
      <td colspan="2">
          <input type="submit" value="查询" />
      </td>
      </tr> 
      </table>
    </form>
     <%
    if(request.getAttribute("error")!=null)
    {
    %>
    <h2 align="center" style="color:red"><%=request.getAttribute("error") %></h2>
    <%
    }
    %>
</html>

<%@page import="dao.*"%>
<%@page import="model.*"%>
<%@page import="Util.*"%>
<%@ 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<%
    String username=request.getParameter("username");
    String password=request.getParameter("password");
    String newpassword=request.getParameter("newpassword");
    String newrepassword=request.getParameter("newrepassword");
    if(username==null||"".equals(username.trim()))
    {
        request.setAttribute("error","请输入要修改的用户名！");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
    if(password==null||"".equals(password.trim()))
    {
        request.setAttribute("error","原密码不能为空！！");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
    if(newpassword==null||"".equals(newpassword.trim()))
    {
        request.setAttribute("error","新密码不能为空！");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
    if(newrepassword==null||"".equals(newrepassword.trim()))
    {
        request.setAttribute("error","必须再次输入新密码，以免出现错误！");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
    User user=new User();
    UserDaoImpl userDao=new UserDaoImpl();
    user=userDao.load(username);
    if(user==null)
    {
        request.setAttribute("error","该用户不存在，请重新输入。");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
    if(!user.getPassword().equals(password))
    {
        request.setAttribute("error", "原密码不正确，无法修改！");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
    if(!newpassword.equals(newrepassword))
    {
        request.setAttribute("error", "两次输入的新密码不一致，请确认后再操作，修改失败！");
%>
    <jsp:forward page="updateInput.jsp"></jsp:forward>
<%
    }
        user.setUsername(username);
        user.setPassword(newpassword);
        userDao.update(user);
%>
    <h2 style="color:blue">用户修改成功！</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>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>用户修改</title>
</head>
<body>
    <form action="update.jsp" method="get">
        <table align="center" border="2" width="500">
            <tr>
            <td>要进行修改的用户名：</td>
            <td>
                <input type="text" name="username" />
            </td>
            </tr>
            <tr>
            <td>原密码：</td>
            <td>
                <input type="password" name="password" />
            </td>
            </tr>
            <tr>
            <td>新密码：</td>
            <td>
                <input type="password" name="newpassword" />
            </td>
            </tr>
            <tr>
            <td>请再次输入密码：</td>
            <td>
                <input type="password" name="newrepassword" />
            </td>
            </tr>
            <tr align="center">
            <td colspan="2">
                <input type="submit" value="提交" />
                <input type="reset" value="重置" />
            </td>
            </tr>
        </table>
    </form>
    <%
    if(request.getAttribute("error")!=null)
    {
    %>
    <h2 align="center" style="color:red"><%=request.getAttribute("error") %></h2>
    <%
    }
    %>
</body>
</html>

package Util;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class Util {
    public  static  Connection getConnection() {
        
            try {
                Class.forName("com.mysql.jdbc.Driver").newInstance();
            } catch (InstantiationException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            } catch (IllegalAccessException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            } catch (ClassNotFoundException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
        String user = "root";
        String password = "root";
        String url = "jdbc:mysql://localhost:3306/jaovo_msg";
        Connection connection = null;
        try {
             connection = DriverManager.getConnection(url,user,password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }
    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();
        }
    }
    
}

课堂测试完成了

三.学习目标

　　　　能自己独立做一个网站

　　　　时间计划，每周将花十个小时以上来学习这门课