i'm new in java and android programming but i accepted a challenge launched by a friend and now i have to work hard.
I finally managed to have this type of activity working with AsyncTask but it seems to work well on all android but not on 4.4.2 KitKat.
The problem seems to be on url.openConnection and i tried many times to change the way in wich i do it but i haven't had positive results...
I have only to read file from an URL
This is my class code:
public class MenuActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu);
new HttpTask().execute();
}
public final class HttpTask
extends
AsyncTask<String/* Param */, Boolean /* Progress */, String /* Result */> {
private HttpClient mHc = new DefaultHttpClient();
#Override
protected String doInBackground(String... params) {
publishProgress(true);
InputStream inputstream = null;
URL url = null;
try {
url = new URL("http://somesite/prova.txt");
} catch (MalformedURLException e) {
e.printStackTrace();
}
assert url != null;
URLConnection connection = null;
try {
connection = url.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
try {
HttpURLConnection httpConnection = (HttpURLConnection) connection;
httpConnection.setRequestMethod("GET");
httpConnection.connect();
if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
inputstream = httpConnection.getInputStream();
}
} catch (Exception ex) {
ex.printStackTrace();
}
ByteArrayOutputStream bytearryoutputstream = new ByteArrayOutputStream();
int i;
try {
i = inputstream.read();
while (i != -1) {
bytearryoutputstream.write(i);
i = inputstream.read();
}
inputstream.close();
} catch (IOException e) {
e.printStackTrace();
}
return bytearryoutputstream.toString();
}
#Override
protected void onProgressUpdate(Boolean... progress) {
}
#Override
protected void onPostExecute(String result) {
StringBuilder nuovafrase=new StringBuilder("");
String[] frasone=result.split("\n");
ListView listView = (ListView)findViewById(R.id.listViewDemo);
ArrayAdapter<String> arrayAdapter;
arrayAdapter = new ArrayAdapter<String>(getApplicationContext(), R.layout.rowmenu, R.id.textViewList, frasone);
listView.setAdapter(arrayAdapter);
}
}
}
And this is the Logcat...
03-11 17:49:37.955 1277-1294/com.example.appsb.app W/System.err﹕ atjava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-11 17:49:37.955 1277-1294/com.example.appsb.app W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ at java.lang.Thread.run(Thread.java:841)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ Caused by: libcore.io.GaiException: getaddrinfo failed: EAI_NODATA (No address associated with hostname)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ at libcore.io.Posix.getaddrinfo(Native Method)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ at libcore.io.ForwardingOs.getaddrinfo(ForwardingOs.java:61)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ at java.net.InetAddress.lookupHostByName(InetAddress.java:405)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ ... 18 more
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ Caused by: libcore.io.ErrnoException: getaddrinfo failed: EACCES (Permission denied)
03-11 17:49:37.959 1277-1294/com.example.appsb.app W/System.err﹕ ... 21 more
03-11 17:49:37.963 1277-1294/com.example.appsb.app W/dalvikvm﹕ threadid=11: thread exiting with uncaught exception (group=0xa4d69b20)
03-11 17:49:37.963 1277-1294/com.example.appsb.app E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
Process: com.example.appsb.app, PID: 1277
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NullPointerException
at com.example.appsb.app.MenuActivity$HttpTask.doInBackground(MenuActivity.java:74)
at com.example.appsb.app.MenuActivity$HttpTask.doInBackground(MenuActivity.java:33)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
There is a Caused by: java.lang.NullPointerException but i cannot understand why...
Thanks
It could be caused by the inputstream being null. inputstream will only be initialized if the response code is OK. So you need to check what response code is being returned. If it is not causing the error, I'd still add some code for if the response code is not OK. You don't want your app to crash if it can't connect. You should at least display a helpful error message
Example:
else{
showErrorMsg();
return null;
}
Catch FileNotFoundException when trying inputstream.read();
try {
i = inputstream.read();
while (i != -1) {
bytearryoutputstream.write(i);
i = inputstream.read();
}
inputstream.close();
} catch (FileNotFoundException e) {
Log.e("MyTag","Handling empty page...");
} catch (IOException e) {
Log.e("MyTag",e.toString());
}
Related
This question already has answers here:
How can I fix 'android.os.NetworkOnMainThreadException'?
(66 answers)
Closed 5 years ago.
Hello i am using android studio to create an App and i have encountered an error which is proving hard to resolve by myself. All i want to do is read a CSV file from a url and for each row add the values to a map marker. I can easily read from a file and add the to my markers, but this url csv read is proving a challenge for me :(. What is my mistake please or even better can it be simplified too.
HttpURLConnection conn = null;
try {
URL url = new URL("http://www.free-map.org.uk/course/mad/ws/get.php?username=user002&format=csv");
conn = (HttpURLConnection) url.openConnection();
InputStream in = conn.getInputStream();
if(conn.getResponseCode() == 200)
{
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String inputLine;
while ((inputLine = br.readLine()) != null) {
String[] comps = inputLine.split(",");
if (comps.length == 5) {
OverlayItem currentItem = new OverlayItem(comps[0], comps[2], new GeoPoint(Double.parseDouble(comps[4]), Double.parseDouble(comps[3])));
pois.addItem(currentItem);
}
}
}
}catch (IOException e){
new AlertDialog.Builder(this).setMessage("ERROR: "+e).show();
}
finally
{
if(conn!=null)
conn.disconnect();
}
I have this code placed in my on Resume() to test if it is working if that helps. and these are the errors displayed in Logcat.
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.edwin.mapping, PID: 2048
java.lang.RuntimeException: Unable to resume activity {com.example.edwin.mapping/com.example.edwin.mapping.HelloMap}: android.os.NetworkOnMainThreadException
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2788)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2817)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
at java.net.InetAddress.getAllByName(InetAddress.java:214)
at com.android.okhttp.internal.Dns$1.getAllByName(Dns.java:28)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:216)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:122)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:292)
at com.android.okhttp.internal.http.HttpEngine.sendSocketRequest(HttpEngine.java:255)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:206)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:345)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:296)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:179)
at com.example.edwin.mapping.HelloMap.onResume(HelloMap.java:158)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1192)
at android.app.Activity.performResume(Activity.java:5310)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2778)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2817)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Application terminated.
use an Async Task to perform the network operation. Do not run it on UI thread.
For example:
private class ReadFile extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
HttpURLConnection conn = null;
try {
URL url = new URL("http://www.free-map.org.uk/course/mad/ws/get.php?username=user002&format=csv");
conn = (HttpURLConnection) url.openConnection();
InputStream in = conn.getInputStream();
if(conn.getResponseCode() == 200)
{
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String inputLine;
while ((inputLine = br.readLine()) != null) {
String[] comps = inputLine.split(",");
if (comps.length == 5) {
OverlayItem currentItem = new OverlayItem(comps[0], comps[2], new GeoPoint(Double.parseDouble(comps[4]), Double.parseDouble(comps[3])));
pois.addItem(currentItem);
}
}
}
}catch (Exception e){
Log.e("Error, e.toString());
}
finally
{
if(conn!=null)
conn.disconnect();
}
return null;
}
#Override
protected void onPostExecute(String result) {
}
#Override
protected void onPreExecute() {}
}
Now call it using:
new ReadFile().execute("");
I am trying to create list view with json .
And this is the Logcat Stacktrace
1215-1239/com.skripsi.mazdamobil E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NullPointerException
at com.skripsi.mazdamobil.Data_Tipsntrick$DownloadList.doInBackground(Data_Tipsntrick.java:186)
at com.skripsi.mazdamobil.Data_Tipsntrick$DownloadList.doInBackground(Data_Tipsntrick.java:164)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Data_Tipsntrick.java:164
private class DownloadList extends AsyncTask<Void,Void,Void> <- line 164
{
protected void onPreExecute()
{
super.onPreExecute();
pDialog = new ProgressDialog(Data_Tipsntrick.this);
pDialog.setMessage("Tunggu Sebentar...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
Data_Tipsntrick.java:186
protected Void doInBackground(Void... unused)
{
String url_param;
url_param="fungsi.php?pl="+filepl+"&kategori="+filekategori;
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(url+url_param);
Log.d("log", "url:" + url + url_param);
try
{
JSONArray result = json.getJSONArray("result"); <<-- line 186
for (int i = 0; i < result.length(); i++)
{
JSONObject c = result.getJSONObject(i);
String id = c.getString("id");
String pesan = c.getString("pesan");
String nama_tipsntrick = c.getString("nama");
String kategori_tipsntrick= c.getString("kategori");
HashMap<String,String> map = new HashMap<String,String>();
map.put(in_id,id);
map.put(in_pesan,pesan);
map.put(in_nama,nama_tipsntrick);
map.put(in_kategori,kategori_tipsntrick);
resultList.add(map);
}
Log.d("log", "bla:" + resultList);
}
catch (JSONException e)
{
e.printStackTrace();
}
return null;
}
next
05-05 11:06:11.299 1215-1215/com.skripsi.mazdamobil E/WindowManager﹕ Activity com.skripsi.mazdamobil.Data_Tipsntrick has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{416ef190 V.E..... R.....ID 0,0-304,96} that was originally added here
android.view.WindowLeaked: Activity com.skripsi.mazdamobil.Data_Tipsntrick has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{416ef190 V.E..... R.....ID 0,0-304,96} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:345)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:239)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:281)
at com.skripsi.mazdamobil.Data_Tipsntrick$DownloadList.onPreExecute(Data_Tipsntrick.java:173)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
at android.os.AsyncTask.execute(AsyncTask.java:534)
at com.skripsi.mazdamobil.Data_Tipsntrick.onCreate(Data_Tipsntrick.java:66)
at android.app.Activity.performCreate(Activity.java:5133)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
Data_Tipsntrick.java:173
protected void onPreExecute()
{
super.onPreExecute();
pDialog = new ProgressDialog(Data_Tipsntrick.this);
pDialog.setMessage("Tunggu Sebentar...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show(); <-- line 173
}
Data_Tipsntrick.java:66
new DownloadList().execute();
What am i doing wrong.Granted i don't know much java.
JSON Response
{"result":[{"id":"7","nama":"sadasdas","kategori":"berkendara","pesan":"dasdasdasdasd"},{"id":"5","nama":"Menggati Ban Bocor","kategori":"berkendara","pesan":"asdsadasdas"}]}
Well you can try this way if you are getting proper JSON response:
...
...
try {
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(url+url_param);
JSONArray result = json.getJSONArray("result");
if(result!=null) {
for (int i = 0; i < result.length(); i++) {
JSONObject c = (JSONObject) result.get(i);
String id = "", pesan = "", nama_tipsntrick = "", kategori_tipsntrick = "";
if (c.has("id"))
id = c.getString("id");
if (c.has("pesan"))
pesan = c.getString("pesan");
if (c.has("nam"))
nama_tipsntrick = c.getString("nama");
if (c.has("kategori"))
kategori_tipsntrick = c.getString("kategori");
HashMap<String, String> map = new HashMap<String, String>();
map.put(in_id, id);
map.put(in_pesan, pesan);
map.put(in_nama, nama_tipsntrick);
map.put(in_kategori, kategori_tipsntrick);
resultList.add(map);
}
}
Log.d("log", "bla:" + resultList);
} catch (JSONException e) {
e.printStackTrace();
}
I need your help, there is an Fatal Error in my code. I don't know how to solve this problem... please help me out :)
my code
public class MainActivity extends Activity {
// button to show progress dialog
Button btnShowProgress;
// Progress Dialog
private ProgressDialog pDialog;
ImageView my_image;
// Progress dialog type (0 - for Horizontal progress bar)
public static final int progress_bar_type = 0;
// File url to download
private static String file_url = "https://example.pdf";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// show progress bar button
btnShowProgress = (Button) findViewById(R.id.btnProgressBar);
// Image view to show image after downloading
my_image = (ImageView) findViewById(R.id.my_image);
/**
* Show Progress bar click event
* */
btnShowProgress.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// starting new Async Task
new DownloadFileFromURL().execute(file_url);
}
});
}
/**
* Showing Dialog
* */
#Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case progress_bar_type: // we set this to 0
pDialog = new ProgressDialog(this);
pDialog.setMessage("Downloading file. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setMax(100);
pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pDialog.setCancelable(true);
pDialog.show();
return pDialog;
default:
return null;
}
}
/**
* Background Async Task to download file
* */
class DownloadFileFromURL extends AsyncTask<String, String, String> {
private SSLContext context;
/**
* Before starting background thread
* Show Progress Bar Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(progress_bar_type);
}
/**
* Downloading file in background thread
* */
#Override
protected String doInBackground(String... f_url) {
int count;
try {
This line is the error in: URL url = new URL(f_url[0]);
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
// Load the truststore that includes self-signed cert as a "trusted" entry.
KeyStore truststore;
truststore = KeyStore.getInstance("BKS");
InputStream in = getActivity().getResources().openRawResource(R.raw.mykeystore);
truststore.load(in, "mysecret".toCharArray());
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
trustManagerFactory.init(truststore);
// Create custom SSL context that incorporates that truststore
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, trustManagerFactory.getTrustManagers(), null);
connection.setSSLSocketFactory(sslContext.getSocketFactory());
connection.connect();
// this will be useful so that you can show a tipical 0-100% progress bar
int lenghtOfFile = connection.getContentLength();
// download the file
InputStream input = new BufferedInputStream(connection.getInputStream(), 8192);
// Output stream
OutputStream output = new FileOutputStream("/sdcard/downloadedfile.pdf");
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
// publishing the progress....
// After this onProgressUpdate will be called
publishProgress(""+(int)((total*100)/lenghtOfFile));
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
private ContextWrapper getActivity() {
// TODO Auto-generated method stub
return null;
}
/**
* Updating progress bar
* */
protected void onProgressUpdate(String... progress) {
// setting progress percentage
pDialog.setProgress(Integer.parseInt(progress[0]));
}
/**
* After completing background task
* Dismiss the progress dialog
* **/
#Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after the file was downloaded
dismissDialog(progress_bar_type);
// Displaying downloaded image into image view
// Reading image path from sdcard
String imagePath = Environment.getExternalStorageDirectory().toString() + "/downloadedfile.pdf";
// setting downloaded into image view
my_image.setImageDrawable(Drawable.createFromPath(imagePath));
}
}
}
and this is my Logcat :
03-21 16:36:26.747: E/AndroidRuntime(5751): FATAL EXCEPTION: AsyncTask #1
03-21 16:36:26.747: E/AndroidRuntime(5751): Process: com.example.test2, PID: 5751
03-21 16:36:26.747: E/AndroidRuntime(5751): java.lang.RuntimeException: An error occured while executing doInBackground()
03-21 16:36:26.747: E/AndroidRuntime(5751): at android.os.AsyncTask$3.done(AsyncTask.java:300)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.util.concurrent.FutureTask.run(FutureTask.java:242)
03-21 16:36:26.747: E/AndroidRuntime(5751): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.lang.Thread.run(Thread.java:841)
03-21 16:36:26.747: E/AndroidRuntime(5751): Caused by: java.lang.NullPointerException: println needs a message
03-21 16:36:26.747: E/AndroidRuntime(5751): at android.util.Log.println_native(Native Method)
03-21 16:36:26.747: E/AndroidRuntime(5751): at android.util.Log.e(Log.java:232)
03-21 16:36:26.747: E/AndroidRuntime(5751): at com.example.test1.MainActivity$DownloadFileFromURL.doInBackground(MainActivity.java:194)
03-21 16:36:26.747: E/AndroidRuntime(5751): at com.example.test1.MainActivity$DownloadFileFromURL.doInBackground(MainActivity.java:1)
03-21 16:36:26.747: E/AndroidRuntime(5751): at android.os.AsyncTask$2.call(AsyncTask.java:288)
03-21 16:36:26.747: E/AndroidRuntime(5751): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
03-21 16:36:26.747: E/AndroidRuntime(5751): ... 4 more
Stacktrace output
03-21 18:39:45.957: W/System.err(2061): java.lang.NullPointerException
03-21 18:39:45.967: W/System.err(2061): at com.example.test1.MainActivity$DownloadFileFromURL.doInBackground(MainActivity.java:147)
03-21 18:39:45.967: W/System.err(2061): at com.example.test1.MainActivity$DownloadFileFromURL.doInBackground(MainActivity.java:1)
03-21 18:39:45.967: W/System.err(2061): at android.os.AsyncTask$2.call(AsyncTask.java:288)
03-21 18:39:45.967: W/System.err(2061): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
03-21 18:39:45.967: W/System.err(2061): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
03-21 18:39:45.967: W/System.err(2061): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-21 18:39:45.967: W/System.err(2061): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-21 18:39:45.967: W/System.err(2061): at java.lang.Thread.run(Thread.java:841)
Try
Log.e("Error:", " " + e.getMessage());
Instead of Log.e("Error: ", e.getMessage());
// e.getMessage() could be null or empty.
Also add catch(MalformedURLException e) {} and see why the url exception is thrown
Make your AsyncTask extend AsyncTask<String, Void, String>.
I'm debugging an Asynctask that simply downloads a file: here the code:
public class AsyncDownloadFilesTask extends AsyncTask<String, Integer, Boolean> {
public AsyncResponse<Boolean> delegate=null;
protected Boolean doInBackground(String... params) {
android.os.Debug.waitForDebugger();
try {
URL url = new URL(params[0]);
int count;
String fileName = new String(params[1]);
URLConnection connessione = url.openConnection();
connessione.connect();
int lenghtOfFile = connessione.getContentLength();
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(fileName);
long total = 0;
byte data[] = new byte[1024];
while ((count = input.read(data)) != -1) {
total += count;
publishProgress((int)((total*100)/lenghtOfFile));
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
return Boolean.valueOf(true);
} catch (Exception e) {
return null;
}
}
protected void onPostExecute(Boolean result) {
delegate.processFinish(result);
}
}
I obtain a strange behaviour: when execution arrive to return
Boolean.valueOf(true);
it skips to
return null;
into the catch block, but Exception e is null, and then debugger goto line 1 of AsyncTask, that is simply
package com.example.compa.asynctasks;
Then execution goes on (executing onPostExecute method) and, of course, returned result is null
What happens? Why debug jump in this way?
Task download correctly the file.
Here code of the Activity that instantiates and calls Async Task
package com.example.compa.activities;
import android.app.Activity;
import ...
public class CoverActivity extends Activity implements AsyncResponse<Boolean>{
ImageView coverImg;
Drawable d;
CompassesFileManager cfm;
int coverId;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cover);
coverId = getIntent().getExtras().getInt("coverId");
cfm = new CompassesFileManager(this);
ImageView coverImg = (ImageView)findViewById(R.id.cover_image);
d = cfm.getCover(coverId);
if (d!=null){
coverImg.setImageDrawable(d);
} else {
AsyncDownloadFilesTask task = new AsyncDownloadFilesTask();
task.delegate = this;
task.execute(cfm.getCoverURL(coverId), cfm.getCoverFileName(coverId));
}
}
#Override
public void processFinish(Boolean output) {
if (output){
Drawable d = cfm.getCover(coverId);
coverImg.setImageDrawable(d);
} else {
finish();
}
}
}
Stacktrace of error:
02-21 19:37:29.520: E/AndroidRuntime(407): FATAL EXCEPTION: main
02-21 19:37:29.520: E/AndroidRuntime(407): java.lang.NullPointerException
02-21 19:37:29.520: E/AndroidRuntime(407): at com.example.compa.asynctasks.AsyncDownloadFilesTask.onPostExecute(AsyncDownloadFilesTask.java:65)
02-21 19:37:29.520: E/AndroidRuntime(407): at com.example.compa.asynctasks.AsyncDownloadFilesTask.onPostExecute(AsyncDownloadFilesTask.java:1)
02-21 19:37:29.520: E/AndroidRuntime(407): at android.os.AsyncTask.finish(AsyncTask.java:631)
02-21 19:37:29.520: E/AndroidRuntime(407): at android.os.AsyncTask.access$600(AsyncTask.java:177)
02-21 19:37:29.520: E/AndroidRuntime(407): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
02-21 19:37:29.520: E/AndroidRuntime(407): at android.os.Handler.dispatchMessage(Handler.java:99)
02-21 19:37:29.520: E/AndroidRuntime(407): at android.os.Looper.loop(Looper.java:176)
02-21 19:37:29.520: E/AndroidRuntime(407): at android.app.ActivityThread.main(ActivityThread.java:5419)
02-21 19:37:29.520: E/AndroidRuntime(407): at java.lang.reflect.Method.invokeNative(Native Method)
02-21 19:37:29.520: E/AndroidRuntime(407): at java.lang.reflect.Method.invoke(Method.java:525)
02-21 19:37:29.520: E/AndroidRuntime(407): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
02-21 19:37:29.520: E/AndroidRuntime(407): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
02-21 19:37:29.520: E/AndroidRuntime(407): at dalvik.system.NativeStart.main(Native Method)
line:
02-21 19:37:29.520: E/AndroidRuntime(407): at com.example.compa.asynctasks.AsyncDownloadFilesTask.onPostExecute(AsyncDownloadFilesTask.java:65)
is the last one of AsyncDownloadFilesTask class, and is a closing bracket, }
Thank you
I don't have enough points to comment, but it looks like delegate is null in your onPostExecute
delegate.processFinish(result); // delegate is null
if that's not the case, you're code stub above doesn't define it though.
I solved on my own.
1st, I move call to the Async Task in the onStart() method, instead of onCreate()
2nd, I made a mistake, in change line
ImageView coverImg = (ImageView)findViewById(R.id.cover_image);
in
coverImg = (ImageView)findViewById(R.id.cover_image);
to avoid a stupid null pointer (I already declared coverImg)!
Anyway, I still don't understand debug's behaviour, but I solved my problem.
Thank you everybody
I have this doInBackground method which records audio streams from the internet. The main work is being done inside while (len != -1) { }. This works fine however the buffer = new byte[] doesn't work as I expected - when the connection is interrupted the IOException is called immidiately and the buffer is not used anymore. How can I make this buffer to "feed" my code till it is empty? I want to have the same behavior like it is in audio players; so first when you connect to the stream (it is buffering), then playing and if the connection is interrupted it is still playing from the buffer (till it is empty).
Recorder:
protected Boolean doInBackground(String... StringUrls) {
boolean fdetermined = false;
Environment env = new Environment();
Calendar c = Calendar.getInstance();
BufferedOutputStream bufOutstream = null;
buffer = new byte[1024 * 10];
int len=-1;
InputStream in = null;
URLConnection conn = null;
try{
conn = new URL(StringUrls[0]).openConnection();
conn.setConnectTimeout(5000);
in = conn.getInputStream();
len = in.read(buffer);
File dir = new File(env.getExternalStorageDirectory() + "/somewhere");
if (!dir.exists()) {
dir.mkdir();
}
filename = env.getExternalStorageDirectory()+"/somewhere/file";
bufOutstream = new BufferedOutputStream(new FileOutputStream(new File(filename)));
} catch (IOException e) {
System.err.println("Caught IOException: " + e.getMessage());
}
while (len != -1) {
if(in != null && buffer != null && bufOutstream != null) {
try {
bufOutstream.write(buffer, 0, len);
len = in.read(buffer);
if (Recorder.this.isCancelled) {
Recorder.this.stopSelf();
break;
}
} catch (IOException e) {
e.printStackTrace();
conn = null;
in = null;
}
}
}
try{
if(bufOutstream != null) {
bufOutstream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
return true;
}
IO Exception:
12-16 14:37:16.999 31950-32021/com.app.example W/System.err﹕ java.net.SocketException: recvfrom failed: ETIMEDOUT (Connection timed out)
12-16 14:37:17.059 31950-32021/com.app.example W/System.err﹕ at libcore.io.IoBridge.maybeThrowAfterRecvfrom(IoBridge.java:542)
12-16 14:37:17.109 31950-32021/com.app.example W/System.err﹕ at libcore.io.IoBridge.recvfrom(IoBridge.java:506)
12-16 14:37:17.109 31950-32021/com.app.example W/System.err﹕ at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488)
12-16 14:37:17.109 31950-32021/com.app.example W/System.err﹕ at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
12-16 14:37:17.119 31950-32021/com.app.example W/System.err﹕ at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
12-16 14:37:17.119 31950-32021/com.app.example W/System.err﹕ at java.io.BufferedInputStream.read(BufferedInputStream.java:304)
12-16 14:37:17.149 31950-32021/com.app.example W/System.err﹕ at libcore.net.http.UnknownLengthHttpInputStream.read(UnknownLengthHttpInputStream.java:41)
12-16 14:37:17.149 31950-32021/com.app.example W/System.err﹕ at java.io.InputStream.read(InputStream.java:163)
12-16 14:37:17.189 31950-32021/com.app.example W/System.err﹕ at com.app.example.Recorder$RecordTask.doInBackground(Recorder.java:376)
12-16 14:37:17.189 31950-32021/com.app.example W/System.err﹕ at com.app.example.Recorder$RecordTask.doInBackground(Recorder.java:288)
12-16 14:37:17.189 31950-32021/com.app.example W/System.err﹕ at android.os.AsyncTask$2.call(AsyncTask.java:264)
12-16 14:37:17.189 31950-32021/com.app.example W/System.err﹕ at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at java.util.concurrent.FutureTask.run(FutureTask.java:137)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at java.lang.Thread.run(Thread.java:856)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ Caused by: libcore.io.ErrnoException: recvfrom failed: ETIMEDOUT (Connection timed out)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at libcore.io.Posix.recvfromBytes(Native Method)
12-16 14:37:17.199 31950-32021/com.app.example W/System.err﹕ at libcore.io.Posix.recvfrom(Posix.java:131)
12-16 14:37:17.209 31950-32021/com.app.example W/System.err﹕ at libcore.io.BlockGuardOs.recvfrom(BlockGuardOs.java:164)
12-16 14:37:17.209 31950-32021/com.app.example W/System.err﹕ at libcore.io.IoBridge.recvfrom(IoBridge.java:503)
I have added finally block below:
while (len != -1) {
if(in != null && buffer != null && bufOutstream != null) {
try {
bufOutstream.write(buffer, 0, len);
len = in.read(buffer);
if (Recorder.this.isCancelled) {
Recorder.this.stopSelf();
break;
}
} catch (IOException e) {
e.printStackTrace();
conn = null;
in = null;
}
finally{
//do your work here. This block will execute no matter of what exception is thrown
try{
if(bufOutstream != null) {
bufOutstream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}