界面作业

1.源代码

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 {
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance();
        } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String user = "sa";
        String password = "123456";
        String url = "jdbc:sqlserver://127.0.0.1:1433;DatabaseName=jaovo_msg";
        Connection connection = null;
        try {
            connection
             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();
        }
    }
    //连接数据库

<%@ 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>用户登录页面</title>
</head>
<body>
    <%String res=(String)request.getAttribute("error");
    if(res=="null"||res==null)
    {
        res="";
    }
    %>
    <%=res%>
    <form action="logincheck.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 align="center">
                <td colspan="2">
                    <input type="submit" value="登录" />
                    <input type="reset" value="重置" />
                    <input type="button" value="注册" onClick="window.location.href='addInput.jsp'"/>
                
                    
                </td>
            </tr>
        </table>
    </form>
</body>
</html>
//网页  html

<%@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");
    if (username == null || "".equals(username.trim())) {
        request.setAttribute("error", "用户名不能为空");
%>
<jsp:forward page="login.jsp"></jsp:forward>
<%
    }
%>
<%
    User user = new User();
    user.setUsername(username);
    user.setPassword(password);

    UserDaoImpl userDao = new UserDaoImpl();
    try {
        if (userDao.checkuser(user)) {
%>
<jsp:forward page="success.jsp"></jsp:forward> 
<%
    } else
    {
        request.setAttribute("error", "用户名/密码有误");
%>

<jsp:forward page="login.jsp"></jsp:forward>
<%
    }
    } catch (UserException e) {
%>
<h2 style="color: red; font-size: 50px">
    发生错误 :
    <%=e.getMessage()%></h2>
<%
    }
%>
</html>

2.截图：

随后还要写一个有关Tomcat安装和作用的博客园

完成上述内容需要一个j较高版本的jdk，MyEclipse10自带的jdk1.6我无法执行出结果用的是自己配置变量时的jdk1.8.

Java web感觉学了Java连门都没入，不会操作数据库，不会写html，没有连接。。。。。。。各种问题都有。

希望以后每星期都有两个小时来学习Java web开发。