java - HttpURLConnection 随机延迟

Question

当我使用 UploadHelper 时，我注意到随机基础上有大约 1.1-1.3 秒的小延迟。所以这不是第二个请求，它可能是第一个，也可能是第四个请求。有时它可以完美地工作，没有任何明显的延迟。似乎在调用 c.getInputStream() 时出现延迟: BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));

有人在我的类(class)中看到了奇怪的行为，或者也许有更好的解决方案来解决这个问题？已经尝试将超时设置从 10.000ms 更改为 1.000ms，这解决了同样的问题，但延迟更大。平均延迟为3秒，当我将超时更改为1000时，延迟变为最大。 1.3秒。

我的类(class):

public class MyUploadHelper {

private static final int timeout = 1000;
private static final String API_SERVER = "http://domain.nl/json/";
private static final String TAG = "MyUploadHelper";

public MyUploadHelper(){

}

public <T> T upload(Class<T> a, String url, Map<String, String> paramMap) throws Exception {

    HttpURLConnection c = null;

    try {
        URL u = new URL(API_SERVER + url);
        c = (HttpURLConnection) u.openConnection();
        // c.setRequestProperty("Content-length", "0");
        c.setUseCaches(false);
        c.setAllowUserInteraction(false);
       // c.setConnectTimeout(timeout);
        c.setReadTimeout(timeout);
        c.setDoOutput(true);

        List<NameValuePair> params = new ArrayList<NameValuePair>();

        for (String key : paramMap.keySet() ) {
            String value = paramMap.get( key );
            params.add(new BasicNameValuePair(key, value));
        }

        OutputStream os = c.getOutputStream();
        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(os, "UTF-8"));
        writer.write(prepareParams(params));

        writer.flush();
        writer.close();


        c.connect();

        int status = c.getResponseCode();
        Log.d(TAG, "Server API URL: " + u.toString() + ", ResponseCode:" + String.valueOf(status));
        switch (status) {
            case 200:
            case 201:
                Gson gson = new Gson();
                BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));
                return gson.fromJson(br, a);
        }

    } 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;
}

private String prepareParams(List<NameValuePair> params) throws UnsupportedEncodingException
{
    StringBuilder result = new StringBuilder();
    boolean first = true;

    for (NameValuePair pair : params)
    {
        if (first)
            first = false;
        else
            result.append("&");

        result.append(URLEncoder.encode(pair.getName(), "UTF-8"));
        result.append("=");
        result.append(URLEncoder.encode(pair.getValue(), "UTF-8"));
    }

    return result.toString();
}


}

Answer 1

尝试设置

c.setConnectTimeout(1000);