Java Android如何在Exception中获取HTTPUrlConnection(POST)响应码和消息？

Question

这是我的情况。我正在使用 POST 消息调用 Web 身份验证 API。成功后，它 return 是一个令牌。否则，它会 return 错误消息 (json) 指定原因（例如："incorrect password", "account lock", etc），响应代码 400, etc。

从浏览器查看的示例错误：

因此，我设法 调用、获取并 return 成功消息，但在出现错误时却没有。下面是伪代码（我省略了多余的部分，主要关注'catch'范围）：

    HttpURLConnection conn = null; //Must define outside as null?
    try {
        ...
        byte[] postDataBytes = ...

        URL url = new URL(urlLogin);
        conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod( "POST" );
        ...
        conn.getOutputStream().write(postDataBytes);

        Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (int c; (c = in.read()) >= 0;)
            sb.append((char)c);
        String response = sb.toString(); // Yeah I got this
        return response;
    }
    catch(IOException ex){
        //the variable ex doesn't tell anything about the response code
        //neither the response message

        //so i access the conn to get
        //
        try {
            int responseCode = conn.getResponseCode();
            return "code: " + responseCode; //somehow this line just doesn't work!
        }
        catch (Exception ex2){
        }
    }

详细一点，IOException 没有说明任何有关响应的信息。所以我访问 HttpURLConnection 变量。

conn.getResponseCode() does return 400,

conn.getResponseMessage() does return "Bad Request"，但不是来自服务器的错误 json 消息。

有什么想法吗？

编辑：

我只想知道，在 Exception/error 期间获得响应 code/message 的正确方法是什么。

Answer 1

getErrorStream() of HttpUrlConnection 可能就是您要找的。

    Reader in = new BufferedReader(new InputStreamReader(conn.getErrorStream(), "UTF-8"));

    // Do you response parsing here.

Java Android如何在Exception中获取HTTPUrlConnection(POST)响应码和消息？

Java Android How to get HTTPUrlConnection (POST) response code and message in the Exception?

java

android

exception

httpurlconnection

http-response-codes