java - HTTPRequest での EOF 例外 (Android 4.1)

Question

HTTPRequest を作成するときに (時々) EOFException が発生します。私はすでに keepalive ="false" を設定しようとしましたが、それは役に立たなかったので、問題は別の場所にあるに違いないと思います..(私は INTERNET 権限を持っています)... この AsyncTask が時々実行されている可能性があることが問題である可能性があります同時に複数回？）私が使用しているコードは

package jo.z.invg.fahrplan;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.List;
import java.util.Scanner;

import org.apache.http.cookie.ClientCookie;
import org.apache.http.cookie.MalformedCookieException;
import org.apache.http.cookie.SetCookie;
import org.apache.http.impl.cookie.BasicExpiresHandler;
import org.apache.http.impl.cookie.BrowserCompatSpec;
import android.os.AsyncTask;
import android.text.TextUtils;
import android.util.Log;
import android.widget.Toast;

class PostRequest extends AsyncTask<PostParam, Void, String> {
    //private Exception exception;
    class LenientCookieSpec extends BrowserCompatSpec {
        public LenientCookieSpec() {
            super();
            registerAttribHandler(ClientCookie.EXPIRES_ATTR, new BasicExpiresHandler(DATE_PATTERNS) {
                @Override public void parse(SetCookie cookie, String value) throws MalformedCookieException {
                    if (TextUtils.isEmpty(value)) {
                        // You should set whatever you want in cookie
                        cookie.setExpiryDate(null);
                    } else {
                        super.parse(cookie, value);
                    }
                }
            });
        }
    }
    private boolean succ = true;
    private int info;
    private int reqnr;
    private ScheduleRequest sreq;
    @Override
    protected String doInBackground(PostParam...postData) {
        //build the string to store the response text from the server
        Log.d("Test", "Anfrage gesendet");
        String response= "***";

        reqnr = postData[0].reqnr;
        sreq = postData[0].req;
                info = postData[0].in;
                System.setProperty("http.keepAlive", "false");
                //do this wherever you are wanting to POST
                URL url;
                HttpURLConnection conn;

                try{
                //if you are using https, make sure to import java.net.HttpsURLConnection
                url=new URL(postData[0].adress);

                //you need to encode ONLY the values of the parameters


                String param = EncodeParam(postData[0].postparam);

                conn=(HttpURLConnection)url.openConnection();
                //set the output to true, indicating you are outputting(uploading) POST data

                conn.setDoOutput(true);
                //once you set the output to true, you don't really need to set the request method to post, but I'm doing it anyway
                conn.setRequestMethod("POST");
                conn.setInstanceFollowRedirects(true);
                //Android documentation suggested that you set the length of the data you are sending to the server, BUT
                // do NOT specify this length in the header by using conn.setRequestProperty("Content-Length", length);
                //use this instead.
                conn.setFixedLengthStreamingMode(param.getBytes().length);
                conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                //conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:15.0) Gecko/20120830 Firefox/15.0");//User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:15.0) Gecko/20120830 Firefox/15.0

                //send the POST out
                PrintWriter out = new PrintWriter(conn.getOutputStream());
                out.print(param);

                out.close();


                //start listening to the stream
                Scanner inStream = new Scanner(conn.getInputStream());

                //process the stream and store it in StringBuilder
                while(inStream.hasNextLine()){
                response+=(inStream.nextLine());}
                //Log.d("HTTPRequest",response);

                conn.disconnect();

                }

                //catch some error
                catch(MalformedURLException ex){  
                //Toast.makeText(MyActivity.this, ex.toString(), 1 ).show();
                    Log.d("HTTPRequest", "Problem beim Postrequest",ex);
                }
                // and some more
                catch(IOException ex){
                    succ = false;
                    if(!(INVG_Fahrplan.INVG_this.isOnline())){INVG_Fahrplan.INVG_this.runOnUiThread(new Runnable() {
                        public void run() {
                            Toast.makeText(INVG_Fahrplan.INVG_this,"Keine Internetverbindung", Toast.LENGTH_LONG).show();
                        }
                    });}
                    else{
                        INVG_Fahrplan.INVG_this.runOnUiThread(new Runnable() {
                            public void run() {
                                Toast.makeText(INVG_Fahrplan.INVG_this,"Fehler bei der Abfrage", Toast.LENGTH_LONG).show();
                            }
                        });
                    }

                    Log.d("HTTPRequest", "Problem beim Postrequest",ex);
                //Toast.makeText(MyActivity.this, ex.toString(), 1 ).show();
                }
                return response;
            }
    public String EncodeParam (List<PostNameValuePair> para){
        String param = "";
        for (PostNameValuePair nvp: para){
            try{
                param += nvp.name +"=" + URLEncoder.encode(nvp.value, "UTF-8") + "&";
            }catch (Exception e){
                Log.d("HTTPRequest", "Problem beim Postrequest",e);
            }

        }
        return param.substring(0, param.length()-1);
    }



    protected void onPostExecute(String result) {
       if(succ){
        if (info == 1){
        sreq.ParseRequest(result,1,-1,reqnr);
       }else if (info == 2){
           sreq.ParseDetails(result,reqnr);
       }}else{
           sreq.reqerror(info);
       }
        //sreq.ParseRequest(result,1);
    }


 }

事前に助けてくれてありがとう; D