Android Asynctask套接字连接

Question

I have been working on a program that sends and receives a string via socket connection to a server. I have used Asynctask to open the connection and send the appropriate commands but no matter what nothing happens! I know the command sending to the server is definitely correct and the server information is correct so I am stumped!

Here is my java code

new internetRoutesRetrieve().execute("");

private class internetRoutesRetrieve extends AsyncTask<String, Void, String> {
            @Override
            protected String doInBackground(String... parms) {
                String userNameSend = userName;
                String response = null;
                try {
                    Socket client = new Socket("Hidden", Hidden);
                    DataOutputStream out = new DataOutputStream(client.getOutputStream());
                    DataInputStream in = new DataInputStream(client.getInputStream());
                    String command = "SEARCH " + userNameSend;
                    out.writeUTF(command);
                    out.flush();
                    String responseServer = in.readUTF();
                    out.close();
                    in.close();
                    response = responseServer;
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return response;
            }
            @Override
            protected void onPostExecute(String result) {
                     //This is always null!
                     System.out.println(result);
                 responseIds = result;
            }
            @Override 
            protected void onPreExecute() {


            }
            @Override
            protected void onProgressUpdate(Void... values) {

            }
        }
}

My LogCat if it helps

    12-09 02:58:52.925: W/System.err(17598): java.io.EOFException
12-09 02:58:53.056: W/System.err(17598):    at libcore.io.Streams.readFully(Streams.java:83)
12-09 02:58:53.056: W/System.err(17598):    at java.io.DataInputStream.readFully(DataInputStream.java:120)
12-09 02:58:53.066: W/System.err(17598):    at java.io.DataInputStream.decodeUTF(DataInputStream.java:195)
12-09 02:58:53.066: W/System.err(17598):    at java.io.DataInputStream.decodeUTF(DataInputStream.java:190)
12-09 02:58:53.066: W/System.err(17598):    at java.io.DataInputStream.readUTF(DataInputStream.java:186)
12-09 02:58:53.066: W/System.err(17598):    at com.example.app.RouteSelection$internetRoutesRetrieve.doInBackground(RouteSelection.java:145)
12-09 02:58:53.066: W/System.err(17598):    at com.example.app.RouteSelection$internetRoutesRetrieve.doInBackground(RouteSelection.java:1)
12-09 02:58:53.066: W/System.err(17598):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
12-09 02:58:53.066: W/System.err(17598):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
12-09 02:58:53.066: W/System.err(17598):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
12-09 02:58:53.066: W/System.err(17598):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
12-09 02:58:53.066: W/System.err(17598):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
12-09 02:58:53.066: W/System.err(17598):    at java.lang.Thread.run(Thread.java:856)

Thanks for any help :)

Answer 1

An EOFException signals, that the input stream reached its end before it was expected. It seems like your server doesn't send you enough data or invalid data.

Make sure you use outputStream.writeUTF(...) on your server.