android - Http响应错误android

Question

我正在从 android 应用程序向 cgi php 服务器发出 HTTP 请求以获取 json 响应。我的应用程序在发出 HTTP 请求之前验证 Internet 连接是否可用。到目前为止，所有事情都正常工作。问题是我有时会因为发出 HTTP 请求后 Internet 连接突然中断而强制关闭。

所以我的问题是

1. 我如何理解我收到了服务器的响应？
2. 我是否需要为响应保留一个计时器？

Answer 1

这是我完美的网络请求处理运行代码

public JSONObject connectToService(String url, final Context context ) {

    try {
        if(!isConnected(context)){
            return;
        }

        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(url);

        HttpParams httpParameters = httpGet.getParams();
        // Set the timeout in milliseconds until a connection is established.
        int timeoutConnection = 7500;
        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
        // Set the default socket timeout (SO_TIMEOUT) 
        // in milliseconds which is the timeout for waiting for data.
        int timeoutSocket = 7500;
        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);

        HttpResponse httpResponse = httpClient.execute(httpGet);
        HttpEntity httpEntity = httpResponse.getEntity();
        InputStream is = httpEntity.getContent();

        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();

        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();

        String jsonString = sb.toString();
        Log.e("WebServiceHandler", "JSON string returned is"+jsonString.toString());

        JSONObject jsonObject = new JSONObject(jsonString);
        return jsonObject;
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (SocketTimeoutException e) {
        e.printStackTrace();
    } catch (ConnectTimeoutException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (JSONException e) {
        e.printStackTrace();
    }

      return null;
}

public boolean isConnected(Context context) {
    ConnectivityManager connMgr = (ConnectivityManager) 
            context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
    if (networkInfo != null && networkInfo.isConnected()) {
        return true;
    } else {
        return false;
    }
}

此代码用于 GET 请求，如果您想使用 POST 请求访问 url，则只需相应地更改此行

HttpGet httpGet = new HttpGet(url);

和

HttpPost httpPost = new HttpPost(url);

Answer 2

首先将所有 HTTP 进程设置为 asyncTask，因为它可能会由于连接速度慢而导致 ANR（应用程序无响应）强制关闭，然后进行适当的异常处理。可以使用以下代码检查服务器响应：

    HttpClient httpclient = new DefaultHttpClient(httpParameters);

        HttpGet httpget = new HttpGet(url + encodedData);

        response = httpclient.execute(httpget);