I want to get matching line, which start with "a" and end for example "140807" in dir.txt read this line and set reading data to my TextView (like this: a152z140807). I don't know why, but my code set blank text in TextView.
Even if i change
data = inputLine;
to:
data = "something";
the text in TextView is setting to blank. Thanks in advance.
TextView poleTextowe;
public void mButton (View view){
URLConnection nbpUrl;
String data = null;
try {
nbpUrl = new URL("http://www.nbp.pl/Kursy/xml/dir.txt").openConnection();
InputStream is = nbpUrl.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String inputLine;
while ((inputLine = reader.readLine()) != null) {
if (inputLine.startsWith("a") && inputLine.endsWith("140807")) {
data = inputLine;
}
}
is.close();
}catch(Exception e){
e.printStackTrace();
}
poleTextowe = (TextView)findViewById(R.id.pole1);
poleTextowe.setText(data);
}
The xml file below:
<TextView
android:text="#string/hello_world"
android:id="#+id/pole1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="#+id/tekst"
android:onClick="mButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/pole1"
android:text="Click"/>
You probably have this exception :
android.os.NetworkOnMainThreadException
Android doesn't allow you to do networking on the main (ui) thread.
Create an async task for example to do networking tasks.
That's easy, your code throws an exception, to be specific, a android.os.NetworkOnMainThreadException. Which means data stays null, and nothing shows. Run it in an AsyncTask or a Thread
Here's an extremely common example. Make this an inner class in your Activity
public class MainActivity extends Activity {
public void onCreate(Bundle b) {
//usual stuff
}
public void doStuff() {
new LongOperation().execute(); //run asynctask
}
private class LongOperation extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
InputStream is = null;
try {
Log.d(TAG, "starting connection");
URLConnection nbpUrl = new URL("http://www.nbp.pl/Kursy/xml/dir.txt").openConnection();
is = nbpUrl.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String inputLine;
while ((inputLine = reader.readLine()) != null) {
if (inputLine.startsWith("a") && inputLine.endsWith("140807")) {
return inputLine; //because if the line's found, no need to look for other lines
}
}
}
catch (Exception e) {
e.printStackTrace();
}
finally {
if (is != null)
is.close(); //close inputstream in finally block, so it always gets closed
}
Log.d(TAG, "asynctask ran");
return "NOT FOUND";
}
#Override
protected void onPostExecute(String data) {
poleTextowe = (TextView) findViewById(R.id.pole1);
poleTextowe.setText(data);
}
#Override
protected void onPreExecute() { }
#Override
protected void onProgressUpdate(Void... values) { }
}
}
Related
This is my main activity which gets a json array from a URL. My problem is that when I try and Unit test what should be in the textview it gives me a null pointer exeption.
public class MainActivity extends AppCompatActivity {
TextView txtJson;
ProgressDialog pd;
public static TextView testString;
String jsonString = null;
List<Location> locations;`enter code here`
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txtJson = (TextView) findViewById(R.id.tvJsonItem);
testString = (TextView) findViewById(R.id.test_for_string);
new JsonTask().execute("https://wsu-dining-service.s3.amazonaws.com/current-menu.json");
}
protected void postCreate()
{
mapStrinToClass();
testString.setText(locations.get(0).getName());
}
private void mapStrinToClass()
{
ObjectMapper objectMapper = new ObjectMapper();
JsonFactory jsonFactory = objectMapper.getFactory();
try {
JsonParser jsonParser = jsonFactory.createParser(jsonString);
locations = objectMapper.readValue(jsonString,
new TypeReference<List<Location>>() {
});
} catch (IOException e) {
e.printStackTrace();
}
}
private class JsonTask extends AsyncTask<String, String, String> {
protected void onPreExecute() {
super.onPreExecute();
pd = new ProgressDialog(MainActivity.this);
pd.setMessage("Please wait");
pd.setCancelable(false);
pd.show();
}
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line+"\n");
Log.d("Response: ", "> " + line); //here u ll get whole response...... :-)
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (pd.isShowing()){
pd.dismiss();
}
jsonString = result;
postCreate();
}
}
}
My unit test
* When I run the app the textview is populated with "Tim & Jeanne's Dining Commons" but the test fails and says the testString.getText().toString(); is null
#Test
public void isMenuCorrect() {
String menuTxt = MainActivity.testString.getText().toString();
assert(menuTxt == "Tim & Jeanne's Dining Commons");
}
First of all, you should use Espresso to run UI tests, under the androidTest folder. Example:
onView(allOf(withId(R.id.tvJsonItem), withText("Tim & Jeanne's Dining Commons")).check(matches(isDisplayed()));
Basically what we're doing here is checking if a view with id R.id.tvJsonItem and with a text "Tim & Jeanne's Dining Commons" is displayed on the screen. Now how to run Espresso tests is not in this question's scope.
Second, your production code should never know what's going on in the tests, like you have created a TextView just to be used in your unit tests.
Finally, never have static references to your views since you can't guarantee your activity has been created by the time you try to access them. In fact, a view should only be seen by its parent. In your case, the reference TextView should be private in your activity.
Im studying android, and i want to make an app that connects to a service and gets the values from there..
main activity:
public class teste extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
new api().execute();
}
}
AsyncTask
public class api extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... params) {
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
try {
URL url = new URL("https://randomuser.me/api/0.7");
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
reader = new BufferedReader(new InputStreamReader(inputStream));
String linha;
StringBuffer buffer = new StringBuffer();
while((linha = reader.readLine()) != null) {
buffer.append(linha);
buffer.append("\n");
}
return buffer.toString();
} catch (Exception e) {
e.printStackTrace();
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
return null;
}
#Override
protected void onPostExecute(String dados) {
}
}
how can i fill a EditText in the mainactivity with the values returned from the asynctask?
Ive searched in the web, but cand find a answer that works..
thankss!
Rafael
Since you don't provide code for your EditText view, consider the following piece of code and modify accordingly to suit your case. You need to write the following on the onPostExecute method of your AsyncTask
#Override
protected void onPostExecute(String dados) {
EditText simpleEditText = (EditText) findViewById(R.id.simpleEditText); //replace here with your editText's id
simpleEditText.setText(dados); //dados contains the result returned from the doInBackground() method
}
EDIT
I now realised that the api class is in different file from the teste class, so you need to pass a reference of the latter one (the activity) to the AyncTask, api. You can do this by declaring a constructor:
public class api extends AsyncTask<Void, Void, String> {
private Activity activity;
//constructor
public api(Activity activity) {
this.activity = activity;
}
//rest of your code
#Override
protected void onPostExecute(String dados) {
EditText simpleEditText = (EditText) activity.findViewById(R.id.simpleEditText); //replace here with your editText's id
simpleEditText.setText(dados); //dados contains the result returned from the doInBackground() method
}
}
and call your api in teste:
public class teste extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
new api(this).execute();
}
}
You don't. The point of an AsyncTask is its asynchronous. It doesn't return anything. You should never call .get() on one, if you do then there's no point in using an AsyncTask. Instead, all the code that needs the result should be placed in onPostExecute.
I am trying to parse some data using JSoup, this is all happening in a asynctask (doInBackground) part of my MainActivity.
Unfortunately all the elements (9) are empty when I execute the app.
When I debug below codeline, I actually get the complete website, it`s all there.
The method readMultipleLinesRespone() is located in another class HttpUtility where I also call my Post and Get requests.
I tested this upfront by saving the website as a file and using JSoups assets ability, it worked perfectly then.
The setupAdapter() method in onPostExecute fills a ExpandableListview with data, should this info be nessecary. If you need more info pls ask.
Can somebody assist and tell me what I am doing wrong?
response1 = util.readMultipleLinesRespone(); <--- debugged and all data (seems) to be there but isn`t.
Edit: If I print response1, there is indeed no data to parse.
Logcat output:
E/Resonse:: [Ljava.lang.String;#3d3410a
Below is the method readMultipleLinesRespone from HttpUtility class:
public String[] readMultipleLinesRespone() throws IOException {
InputStream inputStream = null;
if (httpConn != null) {
inputStream = httpConn.getInputStream();
} else {
throw new IOException("Connection is not established.");
}
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputStream));
List<String> response = new ArrayList<String>();
String line = "";
while ((line = reader.readLine()) != null) {
response.add(line);
}
reader.close();
return (String[]) response.toArray(new String[0]);
}
The asynctask where it`s all hapening:
private class FetchWebsiteData extends AsyncTask<Void, Void, Void> {
ProgressDialog mProgressDialog;
#Override
protected void onPreExecute() {
this.mProgressDialog = new ProgressDialog(getActivity());
mProgressDialog.setMessage("Laden...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
}
#Override
protected Void doInBackground(Void... result) {
try {
util.sendGetRequest("https://mobile.somesite.nl/Data", null);
response1 = util.readMultipleLinesRespone();
} catch (IOException e) {
e.printStackTrace();
}
if (response1.length > 0) {
Document doc = Jsoup.parse(response1.toString());
// Get the html document title
Elements els = doc.select("span[class=item-value pull-right]");
if (els.size() > 0) {
fac_naam = els.get(0).text();
fac_straat = els.get(1).text();
fac_post = els.get(2).text();
con_tel = els.get(3).text();
con_email = els.get(4).text();
betaal_reknr = els.get(5).text();
betaal_houd = els.get(6).text();
zig_gebruiker = els.get(7).text();
zig_wacht = els.get(8).text();
}
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPreExecute();
setupAdapter();
mProgressDialog.dismiss();
}
}
In the meantime I solved the problem.
I did not pass the response string correctly to the asynctask which parses the required elements.
Just required a public string in which the response is being set and passed (not an elegant way but it works):
public static String HttpResponse = "";
In the HttpUtility class:
public String[] readMultipleLinesRespone() throws IOException {
...
TabFragment1.HttpResponse = response.toString();
...
return (String[]) response.toArray(new String[0]);
}
Then pass it to the asynctask:
#Override
protected Void doInBackground(Void... result) {
try {
util.sendGetRequest(LoginActivity.PersData_URL, null);
util.readMultipleLinesRespone();
} catch (IOException e) {
e.printStackTrace();
}
if (HttpResponse.length() > 0) {
Document doc = Jsoup.parse(HttpResponse.toString());
// Get the html document title
Elements els = doc.select("span[class=item-value pull-right]");
...
}
return null;
}
I am new to android and am completely puzzled by AsyncTasks. I need to create a leaderboard which will pull global leaderboard scores from a server.
I have posted below the two methods that were created in the LeaderboardsFragment which are used to access and display the scores - getGlobalScores and readStream.
I am unsure of how to use these in the AsyncTask - mostly how and what parameters to pass to the AsyncTask - most of the tutorials I have been looking at do not deal with 2D arrays. Any hints would be really appreciated, I am really having trouble understanding the literature surrounding this.
package uk.ni.appidemic.whackamole;
import java.io.BufferedReader;
public class LeaderboardsFragment extends Fragment {
AssetStore AS;
private TextView TopScores;
private String[][] global_scores = new String[10][3];
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_leaderboards, container, false);
//Go and get the asset store from the activity
AS = WhackAMoleActivity.getAssetManager();
TopScores = (TextView) rootView.findViewById(R.id.leaderboards);
// Extract and display the top score text view from the preferences
displayLocalScores();
// this method is used to send a highscore to the server (name and score)
// this method may get pulled out to the gameloop as its the only place it should be used in the final game
// but this can be used for testing purposes atm (Server needs to be on)
// sendScoreGlobal("porter", 1001);
//async Get global scores from the server and display them - new thread
new AsyncOperation().execute();
...................
public void getGlobalScores() {
//gets global score in HTML format to be parsed
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
try {
URL url = new URL("http://62........./high_scores");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
readStream(con.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
}
/gets the data and stores the global scores in a 2d array
//it then displays to screen
public void readStream(InputStream in) {
BufferedReader reader = null;
try {
StringBuilder htmlIn = new StringBuilder();
StringBuilder globalScoreBuilder = new StringBuilder();
htmlIn.append("");
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
htmlIn.append(line);
}
// String to be scanned to find the pattern.
String html = htmlIn.toString();
String regexPattern = "<td align=\"left\" style=\"padding-left:10px;\">(\\d+?)</td>|<td align=\"right\" style=\"padding-right:10px;\">(\\w+?)</td>";
// Create a Pattern object
Pattern patternObject = Pattern.compile(regexPattern);
// Now create matcher object.
Matcher matcherObject = patternObject.matcher(html);
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Trying to find regex matches");
TopScores.append("\n");
int nextFreePointer = 0;
int rowCount = 0;
while (matcherObject.find()) {
if (matcherObject.group(1) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(1));
globalScoreBuilder.append(matcherObject.group(1) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(1);
nextFreePointer++;
}
if (matcherObject.group(2) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(2));
globalScoreBuilder.append(matcherObject.group(2) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(2);
nextFreePointer++;
}
if (nextFreePointer > 2) {
nextFreePointer = 0;
rowCount++;
}
globalScoreBuilder.append("\n");
}
StringBuilder sb = new StringBuilder();
String lineSeparator = System.getProperty("line.separator");
for (String[] row : global_scores) {
sb.append(Arrays.toString(row)).append(lineSeparator);
}
String text = sb.toString();
TopScores.append("Global Top 10 Scores\n");
TopScores.append(text);
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public class AsyncOperation extends AsyncTask<String, Void, Void>{
protected void onPreExecute(){
}//end of onPreExecute
#Override
protected Void doInBackground(Void... values) {
}//doinBackground
protected void onProgressUpdate(Void... values){
}//onProgressUpdate
protected void onPostExecute(Void... result){
}//end of onPostExecute
}//end of AsyncOperation inner class
}//end of Leaderboards class
You should fetch your game score through a WebService class that extentds AsynTask. Below is my class that I am using in order to fetch remote data safely.
CODE:
public class WebServiceRestTask extends AsyncTask<HttpUriRequest, Void, Object> {
private static final String TAG = "WebServiceRestTask";
private AbstractHttpClient mClient;
private WeakReference<WebServiceRestCallback> mCallback;
private int ws_task;
public WebServiceRestTask(int ws_task) {
this(new DefaultHttpClient(), ws_task);
}
public WebServiceRestTask(AbstractHttpClient client, int task_number) {
mClient = client;
this.ws_task = task_number;
}
public interface WebServiceRestCallback {
public void onRequestSuccess(String response);
public void onRequestError(Exception error);
}
public void setResponseCallback(WebServiceRestCallback callback) {
mCallback = new WeakReference<WebServiceRestCallback>(callback);
}
#Override
protected Object doInBackground(HttpUriRequest... params) {
try {
HttpUriRequest request = params[0];
HttpResponse serverResponse = mClient.execute(request);
BasicResponseHandler handler = new BasicResponseHandler();
String response = handler.handleResponse(serverResponse);
return response + ws_task;
} catch (Exception e) {
Log.w(TAG, e);
return e;
}
}
#Override
protected void onPostExecute(Object result) {
if (mCallback != null && mCallback.get() != null) {
if (result instanceof String) {
mCallback.get().onRequestSuccess((String) result);
} else if (result instanceof Exception) {
mCallback.get().onRequestError((Exception) result);
} else {
mCallback.get().onRequestError(
new IOException("Unknown Error Contacting Host"));
}
}
}
}
Not at my workstation but think something like this should work.
public class AsyncOperation extends AsyncTask<String, Void, Void>{
private String[][] global_scores = new String[10][3];
protected void onPreExecute(){
// optionally show loading indicator
TopScores.append("\n");
}//end of onPreExecute
#Override
protected Void doInBackground(Void... values) {
try {
URL url = new URL("http://62........./high_scores");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
readStream(con.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
}//doinBackground
protected void onProgressUpdate(Void... values){
}//onProgressUpdate
protected void onPostExecute(Void... result){
// optionally hide loading indicator
StringBuilder sb = new StringBuilder();
String lineSeparator = System.getProperty("line.separator");
for (String[] row : global_scores) {
sb.append(Arrays.toString(row)).append(lineSeparator);
}
String text = sb.toString();
TopScores.append("Global Top 10 Scores\n");
TopScores.append(text);
}//end of onPostExecute
private void readStream(InputStream in) {
BufferedReader reader = null;
try {
StringBuilder htmlIn = new StringBuilder();
StringBuilder globalScoreBuilder = new StringBuilder();
htmlIn.append("");
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
htmlIn.append(line);
}
// String to be scanned to find the pattern.
String html = htmlIn.toString();
String regexPattern = "<td align=\"left\" style=\"padding-left:10px;\">(\\d+?)</td>|<td align=\"right\" style=\"padding-right:10px;\">(\\w+?)</td>";
// Create a Pattern object
Pattern patternObject = Pattern.compile(regexPattern);
// Now create matcher object.
Matcher matcherObject = patternObject.matcher(html);
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Trying to find regex matches");
int nextFreePointer = 0;
int rowCount = 0;
while (matcherObject.find()) {
if (matcherObject.group(1) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(1));
globalScoreBuilder.append(matcherObject.group(1) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(1);
nextFreePointer++;
}
if (matcherObject.group(2) != null) {
Log.d(getActivity().getResources().getString(R.string.LOG_TAG), "Regex match : " + matcherObject.group(2));
globalScoreBuilder.append(matcherObject.group(2) + " ");
global_scores[rowCount][nextFreePointer] = matcherObject.group(2);
nextFreePointer++;
}
if (nextFreePointer > 2) {
nextFreePointer = 0;
rowCount++;
}
globalScoreBuilder.append("\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}//end of AsyncOperation inner class
I am just getting the first 30 lines, how can I view the new lines being generated in my application, here is my code:
package com.example.showinlog;
public class ShowingLog extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
Process process = Runtime.getRuntime().exec("logcat");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder log=new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
log.append(line);
log.append("\n");
}
TextView tv = (TextView)findViewById(R.id.textView1);
tv.setText(log.toString());
} catch (IOException e) {
}
}
}
I'm actually not sure how you get anything. The reading shouldn't ever "end", and since you don't do your reading in a different thread, you should never get to the part where you initialize the TextView.
Even if you did get to a point where you can continually log text, it wouldn't work with this code because you'd never be "done" building your StringBuilder.
Try this. You'll need to pass in a LogcatOut as a callback for the log data:
public class LolCat
{
private Process proc;
private LogcatOut logcatOut;
public LolCat(LogcatOut logcatOut)
{
this.logcatOut = logcatOut;
}
private InputStream inStd;
private InputStream inErr;
private LogcatProcessStreamReader streamReader;
private LogcatProcessStreamReader errStreamReader;
public void start()
{
try
{
proc = Runtime.getRuntime().exec("logcat");
OutputStream os = proc.getOutputStream();
this.inStd = proc.getInputStream();
this.inErr = proc.getErrorStream();
startReaders();
os.flush();
}
catch (IOException e)
{
// App.logExecption("Can't logcat", e);
}
catch (Exception e1)
{
// App.logExecption("Can't logcata", e1);
}
}
private void startReaders() throws FileNotFoundException
{
this.streamReader = new LogcatProcessStreamReader(this.inStd, logcatOut);
this.errStreamReader = new LogcatProcessStreamReader(this.inErr, null);
streamReader.start();
errStreamReader.start();
}
public void kill()
{
proc.destroy();
if (this.streamReader != null)
this.streamReader.finish();
if (this.errStreamReader != null)
this.errStreamReader.finish();
}
public abstract class LogcatOut
{
public abstract void writeLogData(byte[] data, int read) throws IOException;
protected void cleanUp()
{
}
}
class LogcatProcessStreamReader extends Thread
{
private InputStream in;
private boolean done = false;
private LogcatOut logcatOut;
public LogcatProcessStreamReader(InputStream in, LogcatOut logcatOut)
{
this.in = in;
this.logcatOut = logcatOut;
}
#Override
public void run()
{
byte[] b = new byte[8 * 1024];
int read;
try
{
while (!done && ((read = in.read(b)) != -1))
{
if(logcatOut != null)
logcatOut.writeLogData(b, read);
}
if(logcatOut != null)
logcatOut.cleanUp();
}
catch (IOException e)
{
// App.logExecption("Can't stream", e);
}
}
public synchronized void finish()
{
done = true;
}
}
}
In your onCreate:
final Handler handler = new Handler();
new LolCat(new LolCat.LogcatOut()
{
#Override
public void writeLogData(final byte[] data, final int read) throws IOException
{
handler.post(new Runnable()
{
public void run()
{
TextView tv = (TextView) asdf;
tv.setText(tv.getText() + "\n" + new String(data, 0, read));
}
});
}
});
A few caveats:
1) I adapted this from other code I have. I HAVE NOT tested it. You may hit a null pointer exception or the like, but the basic code should work.
2) You do need the log permission (forget what that is)
3) I don't remember if the log data comes from std out or err out. I think its std, but if you're getting nothing, swap.
4) I would not recommend concatting text like I did in here in a text view. You'll need to implement a buffer that can be limited, and large string concats are obviously bad in Java. I'll leave that solution to the reader...
I found the AsyncTasks very useful when trying to implement this.
public class LogCatTask extends AsyncTask<Void, String, Void> {
public AtomicBoolean run = new AtomicBoolean(true);
#Override
protected Void doInBackground(Void... params) {
try {
Runtime.getRuntime().exec("logcat -c");
Process process = Runtime.getRuntime().exec("logcat");
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
StringBuilder log = new StringBuilder();
String line = "";
while (run.get()) {
line = bufferedReader.readLine();
if (line != null) {
log.append(line);
publishProgress(log.toString());
}
line = null;
Thread.sleep(10);
}
}
catch(Exception ex){
}
return null;
}
}
And to implement the task you do something like
public void setupTextView(){
textView.setMovementMethod(new ScrollingMovementMethod());
logCatTask = new LogCatTask(){
#Override
protected void onProgressUpdate(String... values) {
textView.setText(values[0]);
super.onProgressUpdate(values);
}
};
logCatTask.execute();
}