1.工程文件

基本的文件布局，没使用任何css文件，就是简单实现登录注册，页面没有做任何美化；

使用的是MySQL8.0.12，8一下的mysql链接代码有微小差别，网上教程基本都是8一下的，随便找找就能找到；

2.DBBean.java

package Bean;
import java.sql.*;
public class DBBean {
	private String driverStr = "com.mysql.cj.jdbc.Driver";
	private String connStr = "jdbc:mysql://localhost:3306/users?serverTimezone=UTC";
	private String dbusername = "root";
	private String dbpassword = "lufengyu";
	public Connection conn = null;
	public Statement stmt = null;
	
	public DBBean()
	{
		try
		{
			Class.forName(driverStr);
			conn = DriverManager.getConnection(connStr,dbusername,dbpassword);
			stmt = conn.createStatement();
		}
		catch(Exception ex) {
			System.out.println(ex.getMessage());
			System.out.println("mysql链接失败");
		}
	}
	
}

dbusername和dbpassword个人修改过，默认的都是root，这部分就是链接数据库的功能；

3.login.jsp

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







	
		
欢迎登录
		

			

				

					
账号：
					

				
				

					
密码：
					

				
			
			

		
		
没有账号？注册
	

4.check.jsp

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








<%
	request.setCharacterEncoding("utf-8");
	String username=(String)request.getParameter("username");
	String password=(String)request.getParameter("password");
	
	String sql="select * from sky where username="+"'"+username+"'";
	ResultSet rs = db.stmt.executeQuery(sql);
	if(rs.next()){
		if(password.equals(rs.getObject("password"))){
			response.sendRedirect("success.jsp");
		}
		else{
			out.print("");
			response.setHeader("refresh", "0;url=login.jsp");
		}
	}
	else{
		out.print("");
		response.setHeader("refresh", "0;url=login.jsp");
	}
%>

5.zhuce.jsp

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







	
		欢迎注册
		

			

				

					
账号:
					

				
				

					
密码:
					

				
			
			

		
	

6.zhuceck.jsp

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








<%
	request.setCharacterEncoding("utf-8");
	String username=(String)request.getParameter("username");
	String password=(String)request.getParameter("password");
	
	String sqlf="select * from sky where username ="+"'"+username+"'";
	String sqlc="insert into `sky`(`username`,`password`) values ('"+username+"','"+password+"')";
	ResultSet rs = db.stmt.executeQuery(sqlf);
	if(rs.next()){
		out.print("");
		response.setHeader("refresh", "0;url=zhuce.jsp");
	}
	else{
		db.stmt.executeUpdate(sqlc);
		response.sendRedirect("zhucesu.jsp");
	}
%>

7.success.jsp

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







	登陆成功

8.zhucesu.jsp

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







	
注册成功，前往登录

9.数据库创造

CREATE TABLE `sky`
(
    `id` int(5) NOT NULL AUTO_INCREMENT,
    `username` VARCHAr(45) DEFAULT NULL,
    `password` VARCHAr(45) DEFAULT NULL,
    UNIQUE KEY `username_UNIQUE` (`username`),
    PRIMARY KEY (`id`)
)ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
INSERT INTO `sky`(`id`,`username`,`password`)values
('1','admin','admin'),
('2','lfy','lufengyu');

结果（运行login.jsp)

 菜鸡互啄！！