后端配置支持多域名跨域：

$origin = isset($_SERVER['HTTP_ORIGIN']) ? $_SERVER['HTTP_ORIGIN'] : ''; 
$allow_origin = array( 
    'https://www.a.cn', 
    'https://m.b.cn'
); 
if(in_array($origin, $allow_origin)){ 
    header('Access-Control-Allow-Origin:'.$origin); 
    header('Access-Control-Allow-Methods:POST, GET'); 
    header('Access-Control-Allow-Headers:x-requested-with,content-type'); 
    header("Access-Control-Allow-Credentials: true");
}

前端ajax配置：

$.ajax({
            url: "http://localhost:8080/orders",
            type: "GET",
            xhrFields: {
                withCredentials: true
            },
            crossDomain: true,
            success: function (data) {
                render(data);
            }
 });