laravel5.4를 이용한 인증코드 생성 예시에 대한 자세한 설명

<?php 
namespace App\Http\Controllers;

use App\Http\Requests;
use App\Http\Controllers\Controller;

use Illuminate\Http\Request;

//引用对应的命名空间
use Gregwar\Captcha\CaptchaBuilder;
use Session;
class CodeController extends Controller{
 public function captcha($temp)
 {
  $builder = new CaptchaBuilder();
  $builder->build(150,32);
  $phrase = $builder->getPhrase();
  //把内容存入session
  Session::flash(&#39;milkcaptcha&#39;, $phrase); //存储验证码
  ob_clean();
  return response($builder->output())->header(&#39;Content-type&#39;,&#39;image/jpeg&#39;);
 }

}

public function code($tmp)
{
//生成验证码图片的Builder对象，配置相应属性
$builder = new CaptchaBuilder;
//可以设置图片宽高及字体
$builder->build($width = 100, $height = 40, $font = null);
//获取验证码的内容
$phrase = $builder->getPhrase();
//把内容存入session
Session::flash('milkcaptcha', $phrase);
//生成图片
header("Cache-Control: no-cache, must-revalidate");
header('Content-Type: image/jpeg');
$builder->output();
}

public function captcha($temp)
 {
  $builder = new CaptchaBuilder();
  $builder->build(150,32);
  $phrase = $builder->getPhrase();
  //把内容存入session
  Session::flash('milkcaptcha', $phrase); //存储验证码
  ob_clean();
  return response($builder->output())->header('Content-type','image/jpeg');
 }