jdbc连接mysql工具类

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

public class JDBCUtil {
    private static final String URL = "jdbc:mysql://localhost:3306/mydatabase";
    private static final String USER = "username";
    private static final String PASSWORD = "password";

    static {
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(URL, USER, PASSWORD);
    }

    public static void close(Connection conn, PreparedStatement ps, ResultSet rs) {
        try {
            if (rs != null) rs.close();
            if (ps != null) ps.close();
            if (conn != null) conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try {
            conn = getConnection();
            String sql = "SELECT * FROM users WHERE id = ?";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, 1);
            rs = ps.executeQuery();
            while (rs.next()) {
                System.out.println("User ID: " + rs.getInt("id") + ", Name: " + rs.getString("name"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            close(conn, ps, rs);
        }
    }
}