java在Android上从Web API检索JSON

Question

这里。。。我有一个带有MessageController的Web API，它将响应我来自Android的请求并发送JSON（Hello World-只是为了测试一下）

public class MessageController : ApiController
    {
public async Task<IHttpActionResult> SendAsync()
        {

            return Ok(new { text = "hello world" });
        }
    }

从我的Android应用程序中，我想从API中请求JSON。我已经从其他Web API（如currency等）请求过了，但同样的方法在我的API上不起作用

这是：

public void requestMessagesFromApi(View v)
            throws ClientProtocolException, IOException {
        final String response = getJSON(finalUrl);
        TextView msgTV = (TextView) findViewById(R.id.msgTxt);
        msgTV.setText(response);
    }



public String getJSON(String url) {
    HttpURLConnection c = null;
    try {
        URL u = new URL(url);
        c = (HttpURLConnection) u.openConnection();
        c.setRequestMethod("GET");
        c.setRequestProperty("Content-length", "0");
        c.setUseCaches(false);
        c.setAllowUserInteraction(false);
        int status = c.getResponseCode();

        switch (status) {
            case 200:
            case 201:
                BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line+"\n");
                }
                br.close();
                return sb.toString();
        }

    } catch (MalformedURLException ex) {
        Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
    } finally {
        if (c != null) {
            try {
                c.disconnect();
            } catch (Exception ex) {
                Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
    return null;
}

我得到了代码-1的回复。不知道为什么。在最终URL中，我将我的Web API定位在Azure上：

 finalUrl ="http://<hereIsMineWebApiURL>/api/message"

我确信我的API是错的