Simple PHP router

Router.php

<?php
namespace SebastiaanFranken;

use Exception;

class Router
{
	/**
	 * @var array $routes The routing table
	 */
	protected $routes = [];

	/**
	 * @var array $acceptedRequestMethods Accepted HTTP request methods
	 */
	protected $acceptedRequestMethods = ['OPTIONS', 'GET', 'HEAD', 'POST', 'PUT'];

	/**
	 * Creates a new Router instance
	 *
	 * @return void
	 */
	public function __construct()
	{

		/*
		 * Add a GET and POST array
		 */

		$this->routes['GET'] = [];
		$this->routes['POST'] = [];
	}

	/**
	 * Adds a route into the Routing table
	 *
	 * @param string $method The HTTP method. Can be 'POST' or 'GET'
	 * @param string $route The route to respond to
	 * @param callable $callback The callback to invoke
	 * @return SebastiaanFranken\Router
	 */
	protected function setRoute(string $method, string $route, callable $callback) : Router
	{
		$this->routes[$method][$route] = $callback;
		return $this;
	}

	/**
	 * Add a HTTP GET route into the Routing table
	 *
	 * @param string $route The route to respond to
	 * @param callable $callback The callback to invoke
	 * @return SebastiaanFranken\Router
	 */
	public function get(string $route, callable $callback) : Router
	{
		return $this->setRoute('GET', $route, $callback);
	}

	/**
	 * Add a HTTP POST route into the Routing table
	 *
	 * @param string $route The route to respond to
	 * @param callable $callback The callback to invoke
	 * @return SebastiaanFranken\Router
	 */
	public function post(string $route, callable $callback) : Router
	{
		return $this->setRoute('POST', $route, $callback);
	}

	/**
	 * Parses the current HTTP method + URI and sees if
	 * there's a matching route. If there is, it'll execute.
	 *
	 * If not, it throws an error
	 *
	 * @return void
	 */
	public function parseRequest()
	{
		$requestMethod = $_SERVER['REQUEST_METHOD'];
		$queryString = (strlen($_SERVER['QUERY_STRING']) > 0) ? $_SERVER['QUERY_STRING'] : '/';

		if(array_key_exists($requestMethod, $this->routes))
		{
			$table = $this->routes[$requestMethod];

			if(array_key_exists($queryString, $table) && is_callable($table[$queryString]))
			{
				return call_user_func($table[$queryString]);
			}
			else
			{
				throw new Exception(sprintf('There is no callback for %s in the %s routing table', $queryString, $requestMethod));
			}
		}
		else
		{
			throw new Exception(sprintf('There is no %s table in the routing table.', $requestMethod));
		}
	}

	/**
	 * Add a HTTP request method
	 *
	 * @param string $method The HTTP request method to add
	 * @return SebastiaanFranken\Router
	 */
	public function addMethod(string $method) : Router
	{
		$method = strtoupper($method);

		if(in_array($method, $this->acceptedRequestMethods) === true)
		{
			$this->routes[$method] = [];
		}
		else
		{
			throw new Exception(sprintf('The HTTP method %s is not in the accepted request methods list.', $method));
		}

		return $this;
	}
}