java - HttpURLConnection OutputStream 问题

Question

我有以下代码:

String urlString = API_URL + "/checkins/add";  
            String inputdata = "v=20111111"+"&venueId="+venueid+"&broadcast="+broadcast+"&oauth_token="+mAccessToken;  
            String content="";  
            try {  
                URL url = new URL( urlString );
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                con.setRequestMethod("POST");
                con.setDoOutput( true ); 
                con.connect();  

                Log.v("RESPONSE MESSAGE", con.getResponseMessage());

                OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream());  
                out.write(inputdata);  
                out.flush();              

我收到一个错误:

Exception: OutputStream unavailable because request headers have already been sent!

这是为什么？

Answer 1

当您在日志语句中调用 con.getResponseMessage() 时，必须发送 http 消息并读取响应。所以此时使用 OutputStream 添加请求正文为时已晚。只需在写入输入数据后移动日志消息就可以了。