<?phpclass Utils {    /**     * 主要是调用filter_var_array验证，再扩充一个required字段来表示必填项。     * http://www.php.net/manual/zh/book.filter.php     * 注意: (可以不传，但不能传错)     *  1.先验证格式，有失败的抛异常。     *  2.未传的参数，有default的(不管是否required=1)，则设置为default值。     * 示例:     *      $filterArr = array(     *          "pn" =>array(     *              "required"  => 1,     *              "filter"    => FILTER_VALIDATE_INT,     *              "options"   => array(     *                  "default"   =>1,     *                  "min_range" =>1,     *              )     *          )     *      )     */public static function filter_param($paramArr, $filterArr){        $res = filter_var_array($paramArr, $filterArr);     //参数不合法-flase, 没传参数-null        foreach($res as $key=>$val){            //如果有验证失败的，抛出异常。            if(false === $val){                throw new Exception( "Utils::filter_param: failed, key=$key ");            }            //再判断未传的参数。            if( is_null($val)){                //1.如果是必填项                if($filterArr[$key][‘required‘] ){                    if(isset($filterArr[$key][‘options‘][‘default‘])){                        //1.1如果有default值，则设置为default值。                        $res[$key] = $filterArr[$key][‘options‘][‘default‘];                    }else{                        //1.2如果没有default值，抛出异常。                        throw new Exception( "Utils::filter_param: Do not have required param, key=$key" );                    }                }else{                    //$res[$key]=‘‘;      //这里是默认把null值改为空值。是否有必要?                }            }        }        return $res;}};            //每个model里，都写个checkParam函数，用来配置验证的规则。    function checkParam($arrInput){        //1.先检查catId        $filter = array(                //数字类型的，必填。只允许 0-1。            "catId" => array(                "required"=>1,                "filter"=>FILTER_VALIDATE_INT,                "options"=>array(                    "min_range" =>0,                    "max_range" =>1,                )            ),                //字符串类型的，必填。长度大于1。            "title" => array(                "required"=>1,                "filter"=>FILTER_VALIDATE_REGEXP,                "options"=>array(                    "regexp" =>"/^.+/",                )            ),                //字符串类型的，非必填。但要是填了的话，则格式必须为email。            "email" => array(                "filter"=>FILTER_VALIDATE_EMAIL,            ),        );        $_res = Utils::filter_param($arrInput, $filter) ;    }             //比如这个是输入的参数。可以试着修改这里看看效果。    $arrInput=array(        ‘catId‘=>1,        ‘title‘=>‘xx‘,        ‘email‘=>‘xxxxxx.com‘,    );    try{        $res=checkParam($arrInput);        echo "验证通过，继续其它代码...\n";    }catch(Exception $e){        echo ‘Caught exception: ‘,  $e->getMessage(), "\n";    }?>