JDBC 工具类

1.JDBCConfigUtil.java(JDBC的配置工具类)

package login;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class JDBCConfigUtil {
    public JDBCConfigUtil(){}
    //若一个类中的静态方法
    public static Connection getConnection(){
        Connection con=null;
        try{
            //注册驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            
            //android 
            //Class.forName("com.mysql.jdbc.Driver");

            //连接数据库，url地址需要根据实际进行修改
            String url="jdbc:mysql://localhost:3306/day1?serverTimezone=UTC&useSSL=false";
            String user="root";
            //密码需要根据实际情况修改
            String password="plj824";
            con=DriverManager.getConnection(url,user,password);
        } catch (SQLException | ClassNotFoundException e) {
            e.printStackTrace();
        }
        return con;
    }
}

2.JDBCConnectUtil.java(JDBC连接数据库工具类)

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class JDBCConnectUtil {
    public static boolean userLogin(String username,String psw){
        //1.获取数据库连接
        Connection con= JDBCConfigUtil.getConnection();
        String sql="select * from userinfo where username='"+username+"'";
        try {
            //2.获取SQL语句执行者对象
            PreparedStatement pst=con.prepareStatement(sql);
            //3.执行SQL语句，并得到结果集
            ResultSet rs=pst.executeQuery();

            //根据结果集中是否有内容(rs.next()方法)，进行判断
            if(rs.next()){
                if(rs.getString("password").equals(psw)){
                    return true;
                }else {
                    return false;
                }
            }else {
                return false;
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        }
        return false;
    }

    public static boolean userRegister(String username,String password,String email,String company){
        //1.获取数据库连接
        Connection con= JDBCConfigUtil.getConnection();
        String sql="select * from userinfo where userName='"+username+"'";
        try {
            //2.获取SQL语句执行者对象
            PreparedStatement pst=con.prepareStatement(sql);
            //3.执行SQL语句，并得到结果集
            ResultSet rs=pst.executeQuery();

            //根据结果集中是否有内容(rs.next()方法)，进行判断
            if(rs.next()){
                return true;
            }else {
                HibernateConnectUtil.addUserInfoData(username,password,email,company);
                return false;
            }
        } catch (SQLException e1) {
            e1.printStackTrace();
        }
        return false;
    }
}