如何修复“ httpURLConnection响应代码-1”

Question

“请求处理失败；嵌套异常为java.lang.RuntimeException：HttpResponseCode：-1”

我收到此错误消息...

它在更改域之前有效。 （例如10.100.100.10:8080-> dev.note.com:8080）

我试图更改resttemplate调用。

        url = new URL(apiURL);
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setConnectTimeout(3000);
        con.setReadTimeout(3000); 
        con.setRequestMethod("GET");
        con.setDoOutput(true);
        con.setRequestProperty("Accept", "application/json");   

        con.setRequestProperty("Content-Type", "application/json; utf-8");  
        con.connect();

        logger.info(apiURL);
        logger.info("content type="+con.toString());

        // 2. Response Mgs get
        int responseCode = con.getResponseCode();

        if(responseCode != 200) {

            throw new RuntimeException("HttpResponseCode: "+responseCode);
        }

内容类型：未知/未知 HttpResponseCode：-1