java - AsyncTask 执行串行而不是并行(HTTPost TimeOutException)

Question

EDIT: AsyncTask was called lots of times to update status in Server and at the same time, my app tried to upload files. AsyncTask by default, do only one operation at a time (serial mode) but you can put it in Parallel mode, as I answered below.

正常运行几个小时(有时是几分钟)后，我的应用程序停止使用 HTTPost 连接到服务器。我将超时设置为 20 秒，这是一个很好的时间，因为连接良好(wifi)。我已经在两台服务器上进行了测试:我自己的计算机和虚拟专用服务器。这个问题同样会发生。

Android 是否有某种方法或原因可以避免连接到 http 服务器？发生这种情况还有其他原因吗？有更好的方法吗？

谢谢!!

这是我发出 POST 请求的方式:

try{
        new ConexaoHTTPPost.SolicitaDados(parametros).execute(url).get(20000, TimeUnit.MILLISECONDS);
     } catch (InterruptedException e) {
                            new ReportException(getApplicationContext()).send(e,classeToErr);
                        } catch (ExecutionException e) {
                            new ReportException(getApplicationContext()).send(e,classeToErr);
                        } catch (TimeoutException e) {
                            new ReportException(getApplicationContext()).send(e,classeToErr);
                        }

<小时/>

HTTPpost 代码:

public class ConexaoHTTPPost {
    public static String postDados(String urlUsuario, String parametrosUsuario) {
        URL url;
        HttpURLConnection connection = null;

        try {
            url = new URL(urlUsuario);
            connection = (HttpURLConnection) url.openConnection();

            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            connection.setRequestProperty("Content-Lenght","" + Integer.toString(parametrosUsuario.getBytes().length));
            connection.setRequestProperty("Content-Language","pt-BR");
            connection.setUseCaches(false); 
            connection.setDoInput(true);
            connection.setDoOutput(true);

            OutputStreamWriter outputStreamWriter = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
            outputStreamWriter.write(parametrosUsuario);
            outputStreamWriter.flush();
            outputStreamWriter.close();

            InputStream inputStream = connection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));

            StringBuffer resposta = new StringBuffer();

            String linha;
            while ( (linha = bufferedReader.readLine()) != null){
                resposta.append(linha);
                resposta.append('\r');
            }

            bufferedReader.close();

            return resposta.toString();
        }catch (Exception erro){
            return null;
        }finally {
            if(connection != null){
                connection.disconnect();
            }
        }
    }

    public static class SolicitaDados extends AsyncTask<String, Void, String> {

        private String parametros;
        //private String resultado = null;

        public SolicitaDados(String parametros) {
            this.parametros = parametros;
        }

        @Override
        protected String doInBackground(String... urls) {
            return ConexaoHTTPPost.postDados(urls[0], parametros);
        }
        /*
        @Override
        protected void onPostExecute(String resultado){
            this.resultado = resultado;
        }
        */
    }
}

Answer 1

我解决了。我使用的是 execute() 方法，但实际上，正确的方法是在这一行中使用 executeOnExecutor() :

new ConexaoHTTPPost.SolicitaDados(parametros).execute(url).get(20000, TimeUnit.MILLISECONDS);

execute() 在 UI 线程中串行执行所有内容，因此您无法同时上传两个文件(或数据)，因为连接会被 UI 线程阻塞。

使用executeOnExecutor()方法时，可以上传多个文件或数据。我只需更改这一行，如下所示:

new ConexaoHTTPPost.SolicitaDados(parametros).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, url).get(20000, TimeUnit.MILLISECONDS);

我在所有出现的地方都更改了它。PS:您必须使用AsyncTask.THREAD_POOL_EXECUTOR作为线程执行器。