음성인식 문의 드립니다

음성 API
1

curl -v -X POST “https://kakaoi-newtone-openapi.kakao.com/v1/recognize” -H “Transfer-Encoding: chunked” -H “Content-Type: application/octet-stream” -H “Authorization: KakaoAK *****” --data-binary @test.wav

로는 dos 화면에서 결과가 잘 나옵니다.

그런데 java 에서 다음과 변경하여 작업 하였습니다.

StringBuilder urlBuilder = new StringBuilder(“https://kakaoi-newtone-openapi.kakao.com/v1/recognize”);

	    URL url = new URL(urlBuilder.toString());
	    HttpURLConnection conn = (HttpURLConnection) url.openConnection();

	    conn.setRequestMethod("POST");
	    conn.setRequestProperty("Accept", "application/json");
	    conn.setRequestProperty("Transfer-Encoding", "chunked");
	    conn.setRequestProperty("Content-Type", "application/octet-stream");
	    conn.setRequestProperty("Cache-Control","no-cache");
	    conn.setRequestProperty("Authorization", "KakaoAK ********"   );
	    conn.setDoOutput(true);
	    conn.setDoInput(true);
	    conn.setUseCaches(false);		     

    	 OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
 	     writer.write("@heykakao.wav" );
	     writer.flush();
     	 writer.close();
     	 
         conn.getOutputStream().close();

다음과 같은 에러 메시지가 나옵니다. 에러가 나오는 이유가 뭘까요?

------newtoneZF27BywpgLZFcr8HContent-Type: application/json; charset=UTF-8{“type”:“errorCalled”,“value”:“Error 4 Received Nack - no result”}------newtoneZF27BywpgLZFcr8H–