cURL和HttpURLConnection-发布JSON数据

OutputStream希望使用字节，并且您要向其传递字符。试试这个：

HttpURLConnection httpcon = (HttpURLConnection) ((new URL("a url").openConnection()));httpcon.setDoOutput(true);httpcon.setRequestProperty("Content-Type", "application/json");httpcon.setRequestProperty("Accept", "application/json");httpcon.setRequestMethod("POST");httpcon.connect();byte[] outputBytes = "{'value': 7.5}".getBytes("UTF-8");OutputStream os = httpcon.getOutputStream();os.write(outputBytes);os.close();