is there a way to change the urls without compiling the app or deployment once i pushed to the market? the url might change in future or point to different urls.
currently i am hardcoding the urls somethign like this:
try {
url = "http://ofertaweb.ro/android/sleepandlovemusic/" + songs_array[counter] + ".mp3";
mediaPlayer.setDataSource(url);
}
Do not hardcode your URL at project build time, consider writing code that dynamically resolve it at application run time. for example, you can create a static html page (contains a list of actual mp3 URLs), hardcode this static html page URL at project build time, every time your application starting running, query this static html page to get the up-to-date mp3 URL at application run time. there are many alternative way to achieve this, just give you some clue, hope this helps.
here is what i found a way to read the html file:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
public class Get_Webpage {
public String parsing_url = "";
public Get_Webpage(String url_2_get){
parsing_url = url_2_get;
}
public String get_webpage_source(){
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(parsing_url);
HttpResponse response = null;
try {
response = client.execute(request);
} catch (ClientProtocolException e) {
} catch (IOException e) {
}
String html = "";
InputStream in = null;
try {
in = response.getEntity().getContent();
} catch (IllegalStateException e) {
} catch (IOException e) {
}
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuilder str = new StringBuilder();
String line = null;
try {
while((line = reader.readLine()) != null)
{
str.append(line);
}
} catch (IOException e) {
}
try {
in.close();
} catch (IOException e) {
}
html = str.toString();
return html;
}
}
then you read like this:
try {
Get_Webpage obj = new Get_Webpage("http://ofertaweb.ro/android/sleepandlovemusic/list_files.php");
directory_listings = obj.get_webpage_source();
} catch (Exception e) {
}
//Log.d("director listing", directory_listings);
songs_array = directory_listings.split(":::");
Related
I have the following function to allow my android app to communicate with a web server. However the app shows a 'Please Wait' message when I call this code and only disappears if a new activity loads in or if I press the back button. Where is the Please wait coming from and how can I avoid it appearing? Thanks
package util.sapa.sapacontainermanager5;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
public class SimpleWebCalls {
public String executeHttpGet(String serverIP, String nvp) {
String lines="";
serverIP="???????????";
URL url = null;
try {
url = new URL("http://" + serverIP + "/WCF.aspx?" + nvp);
HttpURLConnection conn = null;
try {
conn = (HttpURLConnection) url.openConnection();
try {
conn.setRequestMethod("GET");
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
lines+=line;
}
in.close();
return lines;
} catch (IOException e) {
e.printStackTrace();
}
} catch (ProtocolException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return "";
}
}
the above class is called from:
public String GetDataFromServer(String serverIP,String nvp) {
SimpleWebCalls tWebCall = new SimpleWebCalls();
String sReturn="";
sReturn= tWebCall.executeHttpGet(serverIP,nvp);
return sReturn;
}
the above function is called from:
String data="";
data="doAction=location&u=" + sess.getUserName()+
"&p=" + sess.getPwd() +
"&uid=" + sess.getUserID() +
"&lf=" + sess.encodeStr(editScannedCode.getText().toString());
result = sess.GetDataFromServer(serverIP,data);
follow this tutorial link it might be helpful to you.
add GetDataFromServer() method in to your doInBackground() method.
I am new to android and I am trying to read data from a server. I use a util and call that util like this
private void ParseSource(String Url){
String source = new Cls_SourceGrabber().grabSource(Url);
}
But I am getting a android.os.networkonmainthreadexception. How can I reduce that?
My SourceGrabber util:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URISyntaxException;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
public class Cls_SourceGrabber {
private HttpGet mRequest;
private HttpClient mClient;
private BufferedReader mReader;
private StringBuffer mBuffer;
private String mNewLine;
public Cls_SourceGrabber() {
mRequest = new HttpGet();
InitializeClient();
mReader = null;
mBuffer = new StringBuffer(10000);
mNewLine = System.getProperty("line.separator");
}
private void InitializeClient() {
if (mClient == null || mClient.getConnectionManager() == null) {
HttpParams httpParameters = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParameters, 4500);
HttpConnectionParams.setSoTimeout(httpParameters, 10000);
// HttpConnectionParams.setTcpNoDelay(httpParameters, true);
mClient = new DefaultHttpClient(httpParameters);
}
}
/*
*Grab the full source
*/
public String grabSource(String url) {
mBuffer.setLength(0);
InitializeClient();
String source = "";
try {
mRequest.setURI(new URI(url));
HttpResponse response = mClient.execute(mRequest);
mReader = new BufferedReader(new InputStreamReader(response
.getEntity().getContent()));
String line = "";
while ((line = mReader.readLine()) != null) {
mBuffer.append(line);
mBuffer.append(mNewLine);
source = mBuffer.toString();
if (Thread.interrupted()) {
break;
}
}
} catch (ConnectTimeoutException e) {
source = "Connection Timed Out.";
} catch (java.net.UnknownHostException e) {
source = "No Internet Connection available!";
} catch (java.lang.ArrayIndexOutOfBoundsException e) {
source = "Site Parsing Exception.";
} catch (ClientProtocolException e) {
source = "Protocol Exception.";
} catch (IOException e) {
source = "Server not responding.";
} catch (URISyntaxException e) {
source = "Wrong URL!";
} catch (Exception e) {
source = "Exception - " + e.toString() + " - "
+ e.getMessage();
e.printStackTrace();
} finally {
closeReader();
}
return source;
}
}
First of all, I would not recommend on using HTTPClient any more, since it is not supported any more from sdk version 23.
So, it will be better to migrate the network operations to URL Connection.
Now, android never allows network operations on Main thread since it will block the UI thread for a considerable time, hence may cause crash or bad user experience.
You can take a look on these docs : Doc 1
The better way to do Network operations is by creating an AsyncTask.
Just take care not to access any UI thread element in the doInBackground method. You can modify UI Thread elements on onPreExecute or onPostExecute Methods.
I have created a NetworkOps Util. You can take a look on that, whether it may be any use for you :
import android.content.Context;
import android.net.Uri;
import android.util.Log;
import com.csehelper.variables.Constants;
import com.csehelper.variables.Keys;
import com.csehelper.variables.Url;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.ProtocolException;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.util.ArrayList;
public class NetworkOps {
public final String EXCEPTION = "~Exception~";
/****************************
* Method to Grab Source
****************************/
public static String GrabSource(String URL) {
return PostData(URL, null);
}
/**
* *****************************************
* Method to Grab Source code from URL
* Posting Data
* *****************************************
*/
private static String PostData(String url, Uri.Builder uribuilder) {
String Source;
HttpURLConnection.setFollowRedirects(false);
HttpURLConnection urlConnection = null;
try {
urlConnection = (HttpURLConnection) new URL(url).openConnection();
urlConnection.setDoOutput(true);
urlConnection.setConnectTimeout(10000);
if(uribuilder != null) {
String query = uribuilder.build().getEncodedQuery();
OutputStream os = urlConnection.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
}
urlConnection.connect();
if (urlConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
String line;
StringBuilder builder = new StringBuilder();
InputStreamReader isr = new InputStreamReader(
urlConnection.getInputStream());
BufferedReader reader = new BufferedReader(isr);
while ((line = reader.readLine()) != null) {
builder.append(line);
}
Source = builder.toString();
} else {
Source = EXCEPTION + "Server unreachable. Check network connection.";
}
} catch (SocketTimeoutException e) {
Source = EXCEPTION + "Connection timed out.";
} catch (java.net.UnknownHostException e) {
Source = EXCEPTION + Constants.EXCEPTION_NO_NET;
} catch (ArrayIndexOutOfBoundsException e) {
Source = EXCEPTION + "Server error";
} catch (ProtocolException e) {
Source = EXCEPTION + "Protocol error";
} catch (IOException e) {
Source = EXCEPTION + "Server unreachable. Check network connection.";
} catch (Exception e) {
Source = EXCEPTION + "Error:" + e.toString() + " - "
+ e.getMessage();
e.printStackTrace();
} finally {
if (urlConnection != null) urlConnection.disconnect();
}
return Source;
}
}
Call these Static Functions from AsyncTask:
/*********************************
* AsyncTask to GrabSource
********************************/
class AsyncTask_GrabSource extends AsyncTask<Void, Void, Void> {
String Source = null;
String url = "https://enigmatic-woodland-35608.herokuapp.com/pager.json";
#Override
protected void onPreExecute() {
//Runs on Main Thread. You can access your UI elements here.
}
#Override
protected Void doInBackground(Void... params) {
// Don't access any UI elements from this function
Source = NetworkOps.GrabSource(this.url);
return null;
}
#Override
protected void onPostExecute(Void result) {
if (Source != null) {
if (!Source.contains("~Exception~")) {
//Show Error Message or do whatever you want
} else {
//Do Whatever with your Grabbed Sourcecode.
// This function runs on UI Thread, so you can update UI elements here
}
}
}
You can also post data with the function PostData. In method doInBackground, add this:
Uri.Builder builder = new Uri.Builder()
.appendQueryParameter("key", "value")
.appendQueryParameter("key2", "value2");
Source = NetworkOps.PostData(getApplicationContext(), url, builder);
I'm a android noob on programming, but with some help of a few programms I can learn the basics. I would like to do a basic http get request to an arduino ethernetshield.
For this I've found some code, but I can't get it to work.
I'm allways stuck on the getResponse part with the code I've tried from several pages.
I've found the following page which gave me readable code:
How to work with an image using url in android?
Now I've created the following:
Press on a button and do a get to an url:
package adhttpget.test;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
public class AdhttpgetActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void pushbutton1(View view) {
Toast.makeText(getBaseContext(), "button press", Toast.LENGTH_SHORT).show();
Log.e("button", "pressed");
URL connectURL = new URL("http://192.168.0.48/?out=13&status=2");
HttpURLConnection conn = (HttpURLConnection)connectURL.openConnection();
// do some setup
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("GET");
// connect and flush the request out
conn.connect();
conn.getOutputStream().flush();
// now fetch the results
String response = getResponse(conn); // <-- THIS IS MY PROBLEM
}
private String getResponseOrig(HttpURLConnection conn)
{
InputStream is = null;
try
{
is = conn.getInputStream();
// scoop up the reply from the server
int ch;
StringBuffer sb = new StringBuffer();
while( ( ch = is.read() ) != -1 ) {
sb.append( (char)ch );
}
return sb.toString();
}
catch(Exception e)
{
Log.e("http", "biffed it getting HTTPResponse");
}
finally
{
try {
if (is != null)
is.close();
} catch (Exception e) {}
}
return "";
}
}
Where can I find information to learn how to write the code correctly?
Or do you happen to have the answer in some kind of hint so I can learn from it?
You must create a BufferedReader passing the InputStream, then you can read strings
private static String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
Then I recommend you make the connection (or read/write file) with a separeted thread from the Thread UI (use Thread, AsyncTask, Handler, etc) because that will improve your app.
http://developer.android.com/intl/es/guide/components/processes-and-threads.html
I am unable to figure out why I am stuck at this point although there is no error is my coding. My problem is actually, it doesn't print out my epub, as well as it just hangs there, till the not responding dialog comes up.
My code is as below:
package com.epub;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;
import nl.siegmann.epublib.domain.Book;
import nl.siegmann.epublib.domain.Resource;
import nl.siegmann.epublib.domain.Spine;
import nl.siegmann.epublib.domain.SpineReference;
import nl.siegmann.epublib.epub.EpubReader;
import android.app.Activity;
import android.content.res.AssetManager;
import android.os.Bundle;
import android.util.Log;
import android.webkit.WebView;
import android.widget.TextView;
public class EpubReaderActivity extends Activity {
WebView webView;
Book book;
TextView tv;
String line;
String linez;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv = new TextView(this);
webView = (WebView)findViewById(R.id.webView);
webView.getSettings().setJavaScriptEnabled(true);
AssetManager am = getAssets();
try {
InputStream epubInputStream = am.open("testbook.epub");
book = (new EpubReader()).readEpub(epubInputStream);
} catch (IOException e) {
Log.e("epublib", e.getMessage());
}
Spine spine = book.getSpine();
List<SpineReference> spineList = spine.getSpineReferences() ;
int count = spineList.size();
tv.setText(Integer.toString(count));
StringBuilder string = new StringBuilder();
for (int i = 0; count > i; i++) {
Resource res = spine.getResource(i);
try {
InputStream is = res.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
try {
while ((line = reader.readLine()) != null) {
linez = string.append(line + "\n").toString();
}
} catch (IOException e) {e.printStackTrace();}
//do something with stream
} catch (IOException e) {
e.printStackTrace();
}
}
webView.loadData(linez, "text/html", "utf-8");
}
}
Mind helping me out on this point?
An ANR(Application Not Responding) happens generally when you do a heavy job. In Android, if the OS can't execute one code line within about 5 seconds, the ANR dialog wil pop up. From your codes, it seems that you are reading and parsing an .epub file from your asset folder. I am not familiar with epub files, but I suspect this is a heavy task which blocks your app.
How about start a Thread or AsyncTask to read the file so the main thread would not be blocked?
Pu this code inside a thread as this takes time to write the data and load a web view
Thread is a different part of execution and you will have to wait for few sconds if yor file is large
you can also put a progress dialog to show loading of webview
new Thread(){
public void run() {
for (int i = 0; count > i; i++) {
Resource res = spine.getResource(i);
try {
InputStream is = res.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
try {
while ((line = reader.readLine()) != null) {
linez = string.append(line + "\n").toString();
}
} catch (IOException e) {e.printStackTrace();}
//do something with stream
} catch (IOException e) {
e.printStackTrace();
}
}
};
}.start();
More your file reading code form onCreaate() to onResume(). As data will be read once the UI show to user
I have gone through all the examples and I can not seem to get this to work.
This is my current code:
package hello.android;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class HelloAndroidActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView tv = (TextView) findViewById(R.id.textView1);
try {
// Create a URL for the desired page
URL url = new URL("http://xlradioaustin.com/song/CurrentSong.txt");
// Read all the text returned by the server
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String str;
while ((str = in.readLine()) != null) {
// str is one line of text; readLine() strips the newline character(s)
}
in.close();
tv.setText(str);
} catch (MalformedURLException e) {
tv.setText("mal");
} catch (IOException e) {
tv.setText("io");
}
}
}
Assuming your Android device is online and you've granted your app the INTERNET permission, try this:
try {
// Create a URL for the desired page
URL url = new URL("http://xlradioaustin.com/song/CurrentSong.txt");
// Read all the text returned by the server
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String str;
StringBuilder sb = new StringBuilder(100);
while ((str = in.readLine()) != null) {
sb.append(str);
// str is one line of text; readLine() strips the newline character(s)
}
in.close();
tv.setText(sb.toString());
} catch (MalformedURLException e) {
tv.setText("mal");
} catch (IOException e) {
tv.setText("io");
}
Let me know if that works: you are currently looping until str is null, then using that null value.
A follow up on the answer, it worked after adding
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}