文章目录
一： 添加jar包
在web-inf里新建一个文件夹lib，然后将包拖入,记住一定得是与MySQL同版本的，比如我这是MySQL8，则包为8点多的包，否则，试了好久，出好多错，各种问题
然后
点击+号，然后选择新建的lib包的路径，然后点击OK
然后在Tomcat的bin目录下，将该包复制此目录下
二：代码
try {
Class.forName("com.mysql.cj.jdbc.Driver");//我的jar包下，驱动字符串必须这么写，否则会报错各种的错
String url = "jdbc:mysql://127.0.0.1:3306/db_ai?useSSL=true&characterEncoding=utf-8&serverTimezone=GMT"; //要加上serverTimezone=GMT，否则会报错
String dbuser = "root";
String password = "";//数据库密码
Connection connection = DriverManager.getConnection(url, dbuser, password);
if(connection!=null){
System.out.println("数据库连接成功！");
}else {
System.out.println("数据库连接失败！");
}
}catch (Exception e){
System.out.println(e.getMessage()+e.getCause());
}
三：实现用户登录代码
界面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录界面</title>
</head>
<body>
<p>用户登录界面</p>
<form action="process.jsp" method="post">
用户名：<input type="text" name="user"></br>
密 码：<input type="password" name="passw"></br>
<input type="submit" value="提交">
<input type="reset" value="重置">
</form>
</body>
</html>
<%@ page import="java.sql.*" %><%--
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录界面</title>
</head>
<body>
<%
javax.servlet.http.HttpServletRequest request1 = request;
String user = request1.getParameter("user");//必须要跟界面的value一样
String passw =request1.getParameter("passw");
String userpass=null;
PreparedStatement pstmt = null;
String sql="SELECT mannage_pass FROM manage where mannage_id=?";
ResultSet rs = null;
try {//数据库连接
Class.forName("com.mysql.cj.jdbc.Driver");
String url = "jdbc:mysql://127.0.0.1:3306/db_ai?useSSL=true&characterEncoding=utf-8&serverTimezone=GMT"; //要加上serverTimezone=GMT，否则会报错
String dbuser = "root";//数据库名
String password = "";//密码
Connection connection = DriverManager.getConnection(url, dbuser, password);
if(connection!=null){
System.out.println("数据库连接成功！");
}else {
System.out.println("数据库连接失败！");
}
pstmt=connection.prepareStatement(sql);
pstmt.setString(1,user);
rs=pstmt.executeQuery();
rs.next();
userpass=rs.getString("mannage_pass");
}catch (Exception e){
pstmt.close();
System.out.println(e.getMessage()+e.getCause());
}
if(userpass!=null){
if (userpass.equals(passw)){
%>
<jsp:forward page="success.jsp"></jsp:forward>
<%
}else{
%>
<jsp:forward page="failure.jsp"></jsp:forward>
<%
}
}else {
out.println("用户不存在！");
}
%>
</body>
</html>
