如何在codeigniter中生成rest调用的token？

// Token_model.php

class Token_model extends CI_Model {
    public function generate_token($user_id) {
        $token = uniqid(); // 使用uniqid生成令牌值
        $data = array(
            'token' => $token,
            'user_id' => $user_id,
            'created_at' => date('Y-m-d H:i:s')
        );
        $this->db->insert('tokens', $data);
        return $token;
    }

    public function validate_token($token) {
        $this->db->where('token', $token);
        $this->db->where('created_at >=', date('Y-m-d H:i:s', strtotime('-1 hour'))); // 令牌有效期为1小时
        $query = $this->db->get('tokens');
        return $query->num_rows() > 0;
    }
}

// YourController.php

class YourController extends CI_Controller {
    public function __construct() {
        parent::__construct();
        $this->load->model('Token_model');
    }

    public function your_method() {
        $token = $this->input->get_request_header('Authorization'); // 假设令牌通过请求头传递
        if ($this->Token_model->validate_token($token)) {
            // 令牌有效，执行相应的逻辑
        } else {
            // 令牌无效，返回错误响应或执行其他操作
        }
    }
}