求求大佬给个教程和源代码啊，看了好几个都得需要买。。。。。
有没有大佬给个免费教程和源代码啊，我只是个高中生啊。。。。。
这里有个例子挺好的，参考一下：https://blog.csdn.net/by2233/article/details/83425085
关注我一下。我发给你哦。
//web首页，显示登录注册页面
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<head>
<title>QQ登录页面</title>
<style type="text/css">
</style>
</head>
<body>
<form method="post">
账户:<input type="text" name="name"><br/>
密码:<input type="text" name="password"><br/>
验证码<input type="text"><img src="picture.jsp" /><br/>
<button οnclick="form.action='dologin.jsp'">登录</button>
<button οnclick="form.action='doadd.jsp'">注册</button>
</form>
</body>
//实现注册功能
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.Connection"%>
<%@page import="java.sql.DriverManager"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
request.setCharacterEncoding("utf-8");
String name = request.getParameter("name");
String password = request.getParameter("password");
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql:///mysql_01";
String usename = "root";
String usepasword ="root";
Connection conn = DriverManager.getConnection(url , usename , usepasword);
String sql ="insert into worker values(null,?, ?)";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1,name);
ps.setString(2,password);
ps.executeUpdate();
conn.close();
response.sendRedirect("list.jsp");
%>
//从数据库中获取所有用户数据
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.Connection"%>
<%@page import="java.sql.DriverManager"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<h3 align="center">数据列表</h3>
<table align="center" border="1px" width="300px" height="20px">
<%
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql:///mysql_01";
String usename = "root";
String usepassword ="root";
Connection conn = DriverManager.getConnection(url , usename , usepassword);
String sql = "select * from worker";
PreparedStatement ps=conn.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
while(rs.next()){
%>
<tr align="center">
<td><%=rs.getInt("id") %></td>
<td><%=rs.getString("name") %></td>
<td><%=rs.getString("password") %></td>
<td><a href="del.jsp?name=<%=rs.getInt("id") %>">删除</a></td>
<td><a href="update.jsp?name=<%=rs.getInt("id") %>">修改</a></td>
</tr>
<%
}
conn.close();
%>
</table>
<a href="index.jsp">返回主页面</a>
//实现对数据的删除功能
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.Connection"%>
<%@page import="java.sql.DriverManager"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String id =request.getParameter("name");
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql:///mysql_01";
String usename = "root";
String usepassword ="root";
Connection conn = DriverManager.getConnection(url,usename , usepassword);
String sql = "delete from worker where id="+id;
PreparedStatement ps = conn.prepareStatement(sql);
ps.executeUpdate();
conn.close();
response.sendRedirect("list.jsp");
%>
//数据库实现对要修改的数据的查询
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.Connection"%>
<%@page import="java.sql.DriverManager"%>
<%@page import="java.net.ConnectException"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
request.setCharacterEncoding("utf-8");
String id = request.getParameter("id");
String password = request.getParameter("password");
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql:///mysql_01";
String usename ="root";
String usepassword ="root";
Connection conn = DriverManager.getConnection(url,usename,usepassword);
String sql = "update worker set password=? where id=?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1,password);
ps.setInt(2,Integer.parseInt(id));
ps.executeUpdate();
conn.close();
response.sendRedirect("list.jsp");
%>
//找到数据库中对应的要修改的数据，并对其进行修改
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.Connection"%>
<%@page import="java.sql.DriverManager"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
request.setCharacterEncoding("utf-8");
String id = request.getParameter("name");
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql:///mysql_01";
String usename ="root";
String usepassword ="root";
Connection conn = DriverManager.getConnection(url,usename , usepassword);
String sql ="select * from worker where id=?";
PreparedStatement ps = conn.prepareStatement(sql);
//将字符串的id转换成int型的id
ps.setInt(1, Integer.parseInt(id));
ResultSet rs= ps.executeQuery();
if(rs.next()){
%>
<form align="center" method="post">
<input type="hidden" name="id" value="<%=rs.getInt("id") %>"><br/>
密码:<input type="text" name ="password" value="<%=rs.getString("password") %>">
<button οnclick="form.action='doupdate.jsp'">修改</button>
</form>
<%
}
%>
//登录功能实现从前端获取的数据与数据库的数据进行对比
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.PreparedStatement"%>
<%@page import="java.sql.DriverManager"%>
<%@page import="java.sql.Connection"%>
<%@page pageEncoding="utf-8" %>
<%
String name = request.getParameter("name");
String password = request.getParameter("password");
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/mysql_01";
String servername = "root";
String serverpassword = "root";
Connection conn = DriverManager.getConnection(url , servername , serverpassword);
String sql = "select * from worker";
PreparedStatement ps = conn.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
boolean flag = false;
while(rs.next()){
if(name!=null&&(rs.getString("name")).equals(name)){
if(password!=null&&(rs.getString("password")).equals(password)){
flag = true ;
break;
}else{
flag = false;
}
}else{
flag = false;
}
}
//对flag进行判断
if(flag){
%>
<script>
window.location="login.jsp";
</script>
<%
}else{
%>
<script>
window.location="Client.jsp";
</script>
<%
}
%>
//跳转登录成功页面
<%@page pageEncoding="utf-8" %>
<marquee>登录成功</marquee>
您好，我是有问必答小助手，您的问题已经有小伙伴解答了，您看下是否解决，可以追评进行沟通哦~
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