php处理restful请求的路由类    

<?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;          }      }  ?>