[2] ErrorException in Index.php line 6

session_start(): Cannot send session cookie - headers already sent by (output started at /www/wwwroot/meijipharma.net/runtime/classmap.php:1)

<?php
namespace app\home\controller;
use think\Db;
use clt\Lunar;
use think\facade\Env;
session_start();
class Index extends Common{
    public function initialize(){
        parent::initialize();
    }
    public function index(){
        $data=input('param.');
        if($data['catid'] == 1){
            $whe[]=array('youxiucp','eq',1);
            $this->assign('catid',$data['catid']);
        }
        $product=Db::name("product")
            ->alias('a')
            ->join(config('database.prefix').'category c','a.catid = c.id','left')

Call Stack

in Index.php line 6
at Error::appError(2, 'session_start(): Can...', '/www/wwwroot/meijiph...', 6, ['file' => '/www/wwwroot/meijiph...'])
at session_start() in Index.php line 6
at include('/www/wwwroot/meijiph...') in Loader.php line 411
at think\__include_file('/www/wwwroot/meijiph...') in Loader.php line 132
at Loader::autoload('app\home\controller\...')
at spl_autoload_call('app\home\controller\...')
at class_exists('app\home\controller\...') in App.php line 724
at App->controller('index', 'controller', false, 'EmptyController') in Module.php line 95
at Module->exec() in Dispatch.php line 168
at Dispatch->run() in App.php line 432
at App->think\{closure}(object(Request), object(Closure), null)
at call_user_func_array(object(Closure), [object(Request), object(Closure), null]) in Middleware.php line 185
at Middleware->think\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Middleware.php line 130
at Middleware->dispatch(object(Request)) in App.php line 435
at App->run() in index.php line 21

Environment Variables

Server/Request Data
USER	www
HOME	/home/www
HTTP_CONNECTION	keep-alive
HTTP_CACHE_CONTROL	max-age=259200
HTTP_X_FORWARDED_FOR	10.2.44.243
HTTP_VIA	1.1 squid-proxy-5b5d847c96-m5llr (squid/6.10)
HTTP_HOST	www.meijipharma.net
HTTP_ACCEPT_ENCODING	gzip, br, zstd, deflate
HTTP_USER_AGENT	Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
HTTP_ACCEPT	/
PATH_INFO
REDIRECT_STATUS	200
SERVER_NAME	meijipharma.net
SERVER_PORT	80
SERVER_ADDR	10.61.184.5
REMOTE_PORT	55759
REMOTE_ADDR	216.73.216.207
SERVER_SOFTWARE	nginx/1.26.3
GATEWAY_INTERFACE	CGI/1.1
REQUEST_SCHEME	http
SERVER_PROTOCOL	HTTP/1.1
DOCUMENT_ROOT	/www/wwwroot/meijipharma.net/public
DOCUMENT_URI	/index.php
REQUEST_URI	/sitemap.xml
SCRIPT_NAME	/index.php
CONTENT_LENGTH
CONTENT_TYPE
REQUEST_METHOD	GET
QUERY_STRING	s=/sitemap.xml
SCRIPT_FILENAME	/www/wwwroot/meijipharma.net/public/index.php
FCGI_ROLE	RESPONDER
PHP_SELF	/index.php
REQUEST_TIME_FLOAT	1753745173.3448
REQUEST_TIME	1753745173

ThinkPHP Constants
MAX_MENU_LENGTH	3
MAX_SUB_MENU_LENGTH	5