php - 拉维尔 5.7 : target is not instantiable while building

Question

我知道有很多答案，但我无法真正解决这个问题。

我确实按照这个答案(How to make a REST API first web application in Laravel)在 Laravel 5.7 上创建了一个存储库/网关模式

我在 github 上也有“项目”，如果有人真的好心想要测试/克隆/参见:https://github.com/sineverba/domotic-panel/tree/development (开发分支)

App\Interfaces\LanInterface

<?php
/**
 * Interface for LAN models operation.
 */

namespace App\Interfaces;


interface LanInterface
{

    public function getAll();

}

App\Providers\ServiceProvider

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use Illuminate\Support\Facades\Schema;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        /**
         * Solve the "Key too long" issue
         *
         * @see https://laravel-news.com/laravel-5-4-key-too-long-error
         */
        Schema::defaultStringLength(191);
    }

    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        $this->app->register(RepositoryServiceProvider::class);
    }
}

App\Providers\RepositoryServiceProvider

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;

class RepositoryServiceProvider extends ServiceProvider
{

    public function register()
    {
        $this->app->bind(
            'app\Interfaces\LanInterface',           // Interface
            'app\Repositories\LanRepository'        // Eloquent
        );
    }

}

App\Gateways\LanGateway

<?php

/**
 * The gateway talks with Repository
 */

namespace App\Gateways;
use App\Interfaces\LanInterface;


class LanGateway
{

    protected $lan_interface;

    public function __construct(LanInterface $lan_interface) {
        $this->lan_interface = $lan_interface;
    }

    public function getAll()
    {
        return $this->lan_interface->getAll();
    }

}

App\Repositories\LanRepository

<?php
/**
 * Repository for LAN object.
 * PRG paradigma, instead of "User"-like class Model
 */

namespace App\Repositories;
use App\Interfaces\LanInterface;
use Illuminate\Database\Eloquent\Model;


class LanRepository extends Model implements LanInterface
{

    protected $table = "lans";

    public function getAll()
    {
        return 'bla';
    }

}

我还在 config\app.php 的 providers 部分添加了 App\Providers\RepositoryServiceProvider::class,

这终于是 Controller 了(我知道它还不完整):

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Gateways\LanGateway;

class LanController extends Controller
{

    private $lan_gateway;

    /**
     * Use the middleware
     *
     * @return void
     */
    public function __construct(LanGateway $lan_gateway)
    {
        $this->middleware('auth');
        $this->lan_gateway = $lan_gateway;
    }

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Contracts\Support\Renderable
     */
    public function index()
    {

        $this->lan_gateway->getAll();
        return view('v110.pages.lan');
    }
}

我得到的错误是

Target [App\Interfaces\LanInterface] is not instantiable while building [App\Http\Controllers\LanController, App\Gateways\LanGateway].

我试过:

php artisan 配置:清除php artisan 清晰编译

Answer 1

我认为@nakov 区分大小写可能是正确的。我不相信 PHP 本身关心大小写命名空间，但是 Composer 自动加载器和 Laravel 容器使用 key->value 数组键，确实有区分大小写的键，来绑定(bind)和检索类来自容器。

为确保名称始终匹配，请尝试使用特殊的 ::class相反，像这样:

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use App\Repositories\LanRepository;
use App\Interfaces\LanInterface;

class RepositoryServiceProvider extends ServiceProvider
{

    public function register()
    {
        $this->app->bind(
            LanInterface::class,
            LanRepository::class
        );
    }

}