java和数据库简单连接登录

java与数据库

今天主要试一下简单的登录问题，在数据库里面建个表，属性有姓名和密码，只有这里面的人才能登录成功。
一下是代码实现
上面是我建的一个表，

package com.com.bitedu.db;

import java.sql.*;
import java.util.Scanner;

public class Logain {
    public boolean login(String username,String password){
        if(username==null||password==null){
            return false;
        }
        Connection conn=null;
        PreparedStatement pstml=null;
        ResultSet rs=null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn=DriverManager.getConnection
                    ("jdbc:mysql:///java13","root","root");
            String sql="select * from user where username=? and password= ? ";
            pstml=conn.prepareStatement(sql);
            pstml.setString(1,username);
            pstml.setString(2,password);
            rs=pstml.executeQuery();
            return rs.next();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }catch (SQLException e){
            e.printStackTrace();
        }finally {
            if (rs!=null){
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (pstml!=null){
                try {
                    pstml.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (conn!=null){
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
        return false;
    }


    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入用户名：");
        String username=sc.next();
        System.out.println("请输入你的密码：");
        String password=sc.next();
        Logain logain=new Logain();
        boolean flag=logain.login(username,password);
        if(flag){
            System.out.println("登陆成功");
        }else {
            System.out.println("用户名或密码错误");
        }
    }
}

数据库和java结合可以实现登陆的效果。
下面是结果：

请输入用户名：
赵代猛
请输入你的密码：
520
Fri Jan 31 20:32:46 CST 2020 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
登陆成功

以上就是简单的实现登录效果。