java web用户登录界面

做这次实验,主要用到了mysql  java web 的 内容

实验代码：

IUserDao.java

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();

}

UserDaoImpl.java

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{

@Override
public void add(User user) {
//获得链接对象
Connection connection = DBUtil.getConnection();
//准备sql语句
String sql = "select * from example 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 example(username,password) value (?,?)";
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 {
//关闭资源
DBUtil.close(resultSet);
DBUtil.close(preparedStatement);
DBUtil.close(connection);
}

}

@Override
public void delete(int id){
Connection connection = DBUtil.getConnection();
String sql = "delete from example 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);
}

}

@Override
public void update(User user) {
Connection connection = DBUtil.getConnection();
//准备sql语句
String sql = "update example 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.setInt(3, user.getId());
preparedStatement.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
DBUtil.close(preparedStatement);
DBUtil.close(connection);
}
}

public User load1(int id) {
Connection connection = DBUtil.getConnection();
//准备sql语句
String sql = "select * from example 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"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
DBUtil.close(resultSet);
DBUtil.close(preparedStatement);
DBUtil.close(connection);
}
return user;
}

public User load1(String username){
// TODO Auto-generated method stub
Connection connection = DBUtil.getConnection();
//准备sql语句
String sql = "select * from example where username = ?";
//创建语句传输对象
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
User user = null;
try {
preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, username);
resultSet = preparedStatement.executeQuery();
while(resultSet.next()) {
user = new User();
user.setUsername(username);
user.setId(resultSet.getInt("username"));
user.setPassword(resultSet.getString("password"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
DBUtil.close(resultSet);
DBUtil.close(preparedStatement);
DBUtil.close(connection);
}
return user;

}

public List<User> load(){
Connection connection = DBUtil.getConnection();
//准备sql语句
String sql = "select * from example ";
//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"));
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;
}

@Override
public void add(User user) {
// TODO Auto-generated method stub

}

@Override
public void update(User user) {
// TODO Auto-generated method stub

}

@Override
public User load(int id) {
// TODO Auto-generated method stub
return null;
}

@Override
public User load(String username) {
// TODO Auto-generated method stub
return null;
}

}

User.java

package com.jaovo.msg.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;
}

}

DBUtil.java

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 = "582607kou";
String url = "jdbc:mysql://localhost:33060/mysql";
Connection connection = null;
try {
//2 创建链接对象connection
connection = 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();
}
}

}

UserException.java

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
}

}

indexcheck.java

<%@ page import="com.jaovo.msg.Util.DBUtil" language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@ page import="com.jaovo.msg.model.User"%>>
<%@ page import="com.jaovo.msg.dao.UserDaoImpl"%>>
<!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=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%
request.setCharacterEncoding("UTF-8");
String username=request.getParameter("username");
String password=request.getParameter("password");//取出login.jsp的值
UserDaoImpl a=new UserDaoImpl();
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

User user=a.load(username);
String password1=user.getPassword();
if(password.equals(password1)){
response.sendRedirect("loginsuccess.jsp");
}
else{
out.print("<script language='javaScript'> alert('密码错误');</script>");
response.setHeader("refresh", "0;url=login.jsp");
}
%>
</body>
</html>

login.java

<%@ page import="java.sql.*" language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>登录界面</title>
</head>
<body>
<center>
<h1 style="color:black">登录</h1>
<form id="indexform" name="indexForm" action="indexcheck.jsp" method="post">
<table border="0">
<tr>
<td>账号：</td>
<td><input type="text" name="username"></td>
</tr>
<tr>
<td>密码：</td>
<td><input type="password" name="password">
</td>
</tr>
</table>
<br>
<input type="submit" value="登录" style="color:#BC8F8F">
</form>
<form action="zhuce.jsp">
<input type="submit" value="注册" style="color:#BC8F8F">
</form>
</center>
</body>
</html>

loginsuccess.java

<%@ page import="java.sql.*" 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>Insert title here</title>
</head>
<body>
<h1>登陆成功</h1>
</body>
</html>

实验结果截图：

对自己空闲时间计划的太少，平时不能利用空闲时间来学习java web的内容，以后打算每天用4个小时的时间来学习，编程，周六日时间再加强！