php处理restful请求的路由类分享

<?php
    class router {
        // 路由表
        private $routers = array(
            array("name"=>"userlist", "pattern"=>"get /user", "action"=>"user#get"),
            array("name"=>"userinfo", "pattern"=>"get /user/:s", "action"=>"user#getbyid"),
            array("name"=>"useradd", "pattern"=>"post /user", "action"=>"user#add"),
            array("name"=>"userupdate", "pattern"=>"update /user", "action"=>"user#update"),
            array("name"=>"userdel", "pattern"=>"delete /user/:id", "action"=>"user#delete")
        );

        // 入口
        public function dispatch() {
            $url = $_server["request_uri"];
            $method = $_server["request_method"];

            foreach ($this->routers as $router) {
                $pattern = $router["pattern"];
                $pats = explode(" ", $pattern);
                if (strcasecmp($pats[0], $method) == 0) {
                    // 是否与当前路由匹配
                    $params = $this->checkurl($method, strtolower($url), strtolower($pats[1]));
                    if ($params != null) {
                        array_shift($params);
                        $action = $router["action"];
                        // 寻找到第一个匹配的路由即执行，然后返回
                        return $this->invoke($action, $params);
                    }
                }
            }

            echo "404 error";
            // error 404
        }

        private function invoke($action, $params) {
            $acts = explode("#", $action);
            $classname = $acts[0]."action";
            $methodname = $acts[1];
            $actiondir = dirname(__file__).directory_separator."action";

            // 载入action文件
            $classfile = $actiondir.directory_separator.$classname.".php";
            if (! file_exists($classfile)) {
                // 404 error
                echo "404 error, no action found";
                return;
            } else {
                require "$classfile";
                // 使用反射执行方法
                $rc = new reflectionclass($classname);
                if (! $rc->hasmethod($methodname)) {
                    // 404 error
                    echo "404 error, no method found";
                    return;
                } else {
                    $instance = $rc->newinstance();
                    $method = $rc->getmethod($methodname);
                    $method->invokeargs($instance, $params);
                }
            }
        }

        // 正则匹配检查，并提取出参数
        private function checkurl($method, $str, $pattern) {
            //echo "check $str with $pattern <br>";
            $ma = array();
            $pattern = ltrim(rtrim($pattern, "/"));
            $pattern = "/".str_replace("/", "\/", $pattern)."\/?$/";
            $pattern = str_replace(":s", "([^\/]+)", $pattern);
            //echo "pattern $pattern<br>";
            //$str = "/\".$str."$/";
            if (preg_match($pattern, $str, $ma) > 0) {
                return $ma;
            }
            return null;
        }
    }
?>