I uploaded a text file(*.txt) to a server, now I want to read the text file...
I tried this example without luck.
ArrayList<String> urls=new ArrayList<String>(); //to read each line TextView t; //to show the result try { // Create a URL for the desired page URL url = new URL(""); //My text file location // Read all the text returned by the server BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream())); t=(TextView)findViewById(R.id.TextView1); String str; while ((str = in.readLine()) != null) { urls.add(str); } in.close(); } catch (MalformedURLException e) { } catch (IOException e) { } t.setText(urls.get(0)); // My TextFile has 3 lines App is closing itself... Can it be up to the domain name ? Should there be a IP instead ? I figured out that the while loop isn't executed. Because if I put t.setText* in the while loop there is no error, and the TextView is empty. LogCat Error : it highlight the line with t.setText(urls.get(0));
Thanks in Advance !!!
44 Answers
Try using an HTTPUrlConnection or a OKHTTP Request to get the info, here try this:
Always do any kind of networking in a background thread else android will throw a NetworkOnMainThread Exception
new Thread(new Runnable(){ public void run(){ ArrayList<String> urls=new ArrayList<String>(); //to read each line //TextView t; //to show the result, please declare and find it inside onCreate() try { // Create a URL for the desired page URL url = new URL(""); //My text file location //First open the connection HttpURLConnection conn=(HttpURLConnection) url.openConnection(); conn.setConnectTimeout(60000); // timing out in a minute BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream())); //t=(TextView)findViewById(R.id.TextView1); // ideally do this in onCreate() String str; while ((str = in.readLine()) != null) { urls.add(str); } in.close(); } catch (Exception e) { Log.d("MyTag",e.toString()); } //since we are in background thread, to post results we have to go back to ui thread. do the following for that Activity.this.runOnUiThread(new Runnable(){ public void run(){ t.setText(urls.get(0)); // My TextFile has 3 lines } }); } }).start(); 1-) Add internet permission to your Manifest file.
2-) Make sure that you are launching your code in separate thread.
Here is the snippet which works for me great.
public List<String> getTextFromWeb(String urlString) { URLConnection feedUrl; List<String> placeAddress = new ArrayList<>(); try { feedUrl = new URL(urlString).openConnection(); InputStream is = feedUrl.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8")); String line = null; while ((line = reader.readLine()) != null) // read line by line { placeAddress.add(line); // add line to list } is.close(); // close input stream return placeAddress; // return whatever you need } catch (Exception e) { e.printStackTrace(); } return null; } Our reader function is ready, let's call it by using another thread
new Thread(new Runnable() { public void run() { final List<String> addressList = getTextFromWeb(""); // format your URL runOnUiThread(new Runnable() { @Override public void run() { //update ui } }); } }).start(); just put it inside a new thread and start the thread it will work.
new Thread(new Runnable() { @Override public void run() { try { URL url = new URL("URL");//my app link change it HttpsURLConnection uc = (HttpsURLConnection) url.openConnection(); BufferedReader br = new BufferedReader(new InputStreamReader(uc.getInputStream())); String line; StringBuilder lin2 = new StringBuilder(); while ((line = br.readLine()) != null) { lin2.append(line); } Log.d("texts", "onClick: "+lin2); } catch (IOException e) { Log.d("texts", "onClick: "+e.getLocalizedMessage()); e.printStackTrace(); } } }).start(); thats it.
declare a string variable to save text:
public String txt; declare a method to check connectivity:
private boolean isNetworkConnected() { ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); return cm.getActiveNetworkInfo() != null; } delare an AsyncTask like this:
private class ReadFileTask extends AsyncTask<String,Integer,Void> { protected Void doInBackground(String...params){ URL url; try { //create url object to point to the file location on internet url = new URL(params[0]); //make a request to server HttpURLConnection con=(HttpURLConnection)url.openConnection(); //get InputStream instance InputStream is=con.getInputStream(); //create BufferedReader object BufferedReader br=new BufferedReader(new InputStreamReader(is)); String line; //read content of the file line by line while((line=br.readLine())!=null){ txt+=line; } br.close(); }catch (Exception e) { e.printStackTrace(); //close dialog if error occurs } return null; } now call AsyncTask with desired Url:
if(isNetworkConnected()) { ReadFileTask tsk=new ReadFileTask (); tsk.execute(""); } and dont forget to add following permission in Manifest:
<uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
