laravel5.1中文件上传操作出现错误

以下是代码（想问一下该如何修改。自己小白一个，先提前谢谢大家！）：
<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;

class RequestController extends Controller
{

public function getFileupload(){
    $postUrl='/laravelFirst/public/index.php/request/fileupload';
    $csrf_field=csrf_field();
    $html=<<<FILE
    <form action="$postUrl" method="post" enctype="multipart/form-data">
    $csrf_field
    <input type="file" name="file"><br/>
    <input type="submit" value="提交">
    </form>

FILE;

    return $html;          
}
public function postFileupload(Request $request){
    if(!$request->hasFile('file')){
        exit('上传文件为空!');
    }
    $file=$request->file('file');
    if(!$file->isValid()){
        exit('上传文件出错!');
    }
    $destPath = realpath(public_path('images'));
    if(!file_exists($destPath)){
    mkdir($destPath,0755,true);
}
    $filename=$file->getClientOriginalName();
    if(!$file->move($destPath,$filename)){
        exit('保存文件失败！');
    }
    exit('文件上传成功!');
}

}

---

你打印那个destPath看看