Magento 2 : Controller Return XML or JSON

public function __construct(

\Magento\Framework\App\Action\Context $context,

\Magento\Framework\Controller\Result\RawFactory $resultPageFactory

) {

$this->resultPageFactory = $resultPageFactory;

parent::__construct($context);

}

public function execute()

{

$result = $this->resultPageFactory->create();

$xmlDummy = ‘<?xml version=”1.0″ encoding=”UTF-8″ standalone=”yes”?>

<SomeXMLTag>
<MyTag>MyValue</MyTag>

</SomeXMLTag>

‘;

$result->setHeader(‘Content-Type’, ‘text/xml’);

$result->setContents($xmlDummy);

return $result;

}

for JSON you can use, but without setHeader

\Magento\Framework\Controller\Result\JsonFactory