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Trying to get the MediaRecorder to reset and also to continue running when I change to a different class

Currently I am facing three issues:
Getting the MediaRecorder to reset instead of release.
I think i need to create a new instance of the MediaRecorder and release() it as well, but I do not know where.
I want it to keep recording audio until the phone dies and even when the user changes to a different screen (i.e. going to a new class).
I have tried to google this but do not know how to achieve it.
Edit - I figured out how to use SimpleDateFormat!
Edit 2 - Realised I need to create a started service for my 2nd issue.
My code is as follows
Class:
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.TextView;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Drugs extends AppCompatActivity {
WebView myBrowser;
MediaRecorder mRecorder;
private static String audioFilePath;
public boolean isRecording = false;
MediaPlayer mediaPlayer;
public boolean isPlaying = false;
SimpleDateFormat simpledate;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_drugs);
myBrowser = (WebView) findViewById(R.id.mybrowser);
myBrowser.loadUrl("file:///android_asset/drugs.html");
myBrowser.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
Button btndrugslaw = (Button) findViewById(R.id.drugslaw);
btndrugslaw.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent intentdruglaw = new Intent(Drugs.this, DrugLaw.class);
startActivity(intentdruglaw);
}
});}
public void RecordButton (View view) {
if(mRecorder == null){
audioFilePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + simpledate
+ "/myaudio.3gp";
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setOutputFile(audioFilePath);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
}
if (isRecording) {
try{
stopRecording();
isRecording = false;
((Button)view).setText("Start Recording");
}catch(Exception e){
e.printStackTrace();
}
} else {
try{
startRecording();
isRecording = true;
((Button)view).setText("Stop Recording");
}catch(Exception e){
e.printStackTrace();
}
}
}
public void startRecording() throws IllegalStateException, IOException{
mRecorder.prepare();
MediaRecorder mRecorder = new MediaRecorder();
mRecorder.start();
}
public void stopRecording() throws IllegalStateException, IOException{
mRecorder.stop();
mRecorder.reset();
}
public void StartPlaying(View view) throws IllegalStateException, IOException {
if (mediaPlayer == null) {
mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource(audioFilePath);
}
if (isPlaying) {
try {
stopPlaying();
isPlaying = false;
((Button)view).setText("Play Audio");
} catch (Exception e) {
e.printStackTrace();
}
} else {
try{
startPlaying();
isPlaying = true;
((Button)view).setText("Stop Audio");
} catch (Exception e) {
e.printStackTrace();
}
}
}
public void startPlaying() throws IllegalStateException, IOException {
mediaPlayer.prepare();
mediaPlayer.start();
}
public void stopPlaying () throws IllegalStateException, IOException {
mediaPlayer.release();
}
}

Trying to check if textfile with same name has already been created

I am trying to create a basic app where I input text to the app, this text names a text file, then the app adds extra text to the file. If a text file with the same name already exists, I want to output "file exists". At the moment from what I can see, the check to see if a file with the same name already exists is not working. Can anybody see why? From what I see it should work. Here is the code:
package com.example.user.filetest;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.io.File;
public class MainActivity extends AppCompatActivity {
FileUtility myFile = new FileUtility();
private File root;
private File file;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final EditText enter = ((EditText) findViewById(R.id.editText));
final TextView show = ((TextView) findViewById(R.id.textView));
Button b = ((Button) findViewById(R.id.button));
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
final String s = enter.getText().toString();
file = new File(root, "//" + s);
if (file.exists()) {
show.setText("File Exists");
}
else {
myFile.createFile(getApplicationContext(), s);
myFile.writeLine("test");
show.setText(myFile.readAll());
}
}
}
);
}
package com.example.user.filetest;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import android.content.Context;
import android.os.Environment;
import android.util.Log;
import android.content.*;
public class FileUtility {
private File root;
private File file;
public FileUtility() {
root = Environment.getExternalStorageDirectory();
}
public void createFile(Context context, String fileName) {
try {
if (root.canWrite()) {
file = new File(root, "//" + fileName);
if (!file.exists()) {
file.createNewFile();
}
}
else
{
file = new File(context.getFilesDir(), "//" + fileName); // File(root, "//" + fileName);
if (!file.exists()) {
file.createNewFile();
}
}
} catch (IOException e) {
Log.e("Error", "fail to create a new file");
}
}
public String readAll() {
StringBuilder returnString = new StringBuilder();
try {
BufferedReader in;
FileReader datawriter = new FileReader(file);
in = new BufferedReader(datawriter);
if (file.exists()) {
String str = null;
while((str=in.readLine())!=null)
{
returnString.append(str + "\n");
}
}
in.close();
} catch (IOException e) {
Log.e("Error", "fail to write file");
}
return returnString.toString();
}
public void writeLine(String message) {
try {
BufferedWriter out;
FileWriter datawriter = new FileWriter(file,true);
out = new BufferedWriter(datawriter);
if (file.exists()) {
out.write(message + "\n");
out.flush();
}
out.close();
} catch (IOException e) {
Log.e("Error", "fail to write file");
}
}
}

You have an issue in the way you declare and initialize File root in both classes.
In MainActivity :
The File root attribute is not initialized
Change your code to
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
root = Environment.getExternalStorageDirectory(); // Initialilze the root file here
// ...
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
final String s = enter.getText().toString();
file = new File(root, "//" + s);
if (file.exists()) {
show.setText("File Exists");
}
else {
myFile.createFile(root, getApplicationContext(), s); // pass the root file as parameter
myFile.writeLine("test");
show.setText(myFile.readAll());
}
}
}
);
}
In FileUtility :
As you are also using the root in FileUtility to create the new file you can pass it as parameter and then remove the class attribute .
class FileUtility{
private File file;
public FileUtility() {
}
public void createFile(File root, Context context, String fileName){
// Use the root initialized into the main activity
//...
And the you

After 'takePicture' call, 'onPictureTaken' response is dependent on location in app...why?

I'm trying to build an app which will periodically call the Camera to take a picture and save it.
My problem is that unless I put the 'takePictuce' call in the 'onCreate' the response to 'takePicture' (onPictureTaken) is never called.
I've broken down the app as simply as possible to illustrate.
if a class to handle the camera is partially defined as:
public class CameraHandler {
private Camera mCamera;
public CameraHandler(){
mCamera = Camera.open();
mCamera.setPreviewTexture(new SurfaceTexture(10));
mCamera.startPreview();
mCamera.takePicture(null, null, mPicture);
}
Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
} catch (IOException e) { }
}
};
Then when I put the following code into MainActivity.java, 'onPictureTaken' IS called when CameraHandler is instantiated.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
CameraHandler cameraHandler = new CameraHandler();
}
However, putting the call to instantiate CameraHandler in a click event in the MainActivity.java will NOT call 'onPictureTaken' in response to the takePicture call.
(This snippet is located in MainACtivity.java)
public void onClickListener(View view){
CameraHandler cameraHandler = new CameraHandler();
}
So why is this occurring, and how can I get the call to take a picture in the class where it belongs and not in the 'main' of the program?
All help welcome

Finally figured out how to set the phone to take timed pics without any screen display.
There were 2 main issues I struggled with. First, I wanted to take the pics without displaying to screen. Along those lines, I found an example where they used :
mCamera.setPreviewTexture(new SurfaceTexture(10));
and nothing showed on the screen when using this preview method. It appears that some sort of preview is required. Another method was to set the preview to 1 pixel. This method had examples online which appeared to work as well, but I did not try it.
The second and bigger problem had to do with 'onPictureTaken' method. This method processes your picture after the 'takePicture' call.
It seemed that no matter what looping method I used, or where in the code the call to 'takePicture' was located, all of the 'onPictureTaken' methods were queued up and called one after another once the parent of the 'takePicture' caller ended.
Although the picture data processed by onPictureTaken were in a proper time sequence, I could see that having several hundred pics stored and waiting to process could cause problems, and a method needed to be found where on pic was processed and stored before the next pic was taken.
Along those lines, I stumbled upon the AlarmManager and coupled that with the BroadcastReceiver and Future classes to solve the problem.
What I've done is set the alarmManger to go off at a set time or time frequency. The BroadcaseReceiver captures this call & in turn calls a method which creates
a thread where a 'Future' object makes the call to take a picture.
'Future' object is nice, because it will wait for the physical camera to take the picture (takePicture) and then process it (onPictureTaken). This all occurs in one thread, then terminates. So no queuing of pics to process and each picture sequence is handled separately.
Code is contained below. Note that some of the default 'Overrides' have been left out to save space. Also, the visible screen was basically a button which captured the click event...very basic.
MainActivity.java:
package myTest.com.test;
import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.SystemClock;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class MainActivity extends Activity {
CameraHandler cameraHandler;
public BroadcastReceiver br;
public PendingIntent pi;
public AlarmManager am;
final static private long LOOPTIME = 20000;
private static final ExecutorService threadpool = Executors.newFixedThreadPool(3);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setup();
}
private void setup() {
try{
cameraHandler = new CameraHandler();
br = new BroadcastReceiver() {
#Override
public void onReceive(Context c, Intent i) {
//Toast.makeText(c, "Taking a pic!", Toast.LENGTH_LONG).show();
TryAThread();
}
};
registerReceiver(br, new IntentFilter("com.timedActivity.activity") );
pi = PendingIntent.getBroadcast(this, 0, new Intent("com.timedActivity.activity"), 0);
am = (AlarmManager)(this.getSystemService( Context.ALARM_SERVICE ));
}
catch (Exception e){ }
}
private void TryAThread() {
try{
CameraCaller cameraCaller = new CameraCaller(cameraHandler);
Future future = threadpool.submit(cameraCaller);
while (!future.isDone()) {
try {
Thread.sleep(5000);
} catch (Exception ex) { }
}
}
catch (Exception e){ }
}
#Override
protected void onDestroy() {
am.cancel(pi);
unregisterReceiver(br);
super.onDestroy();
}
public void onClickListener(View view){
try{
am.setRepeating(am.ELAPSED_REALTIME,SystemClock.elapsedRealtime(), LOOPTIME, pi);
}
catch (Exception e){ }
}
}
CameraCaller.java:.
package myTest.com.test;
import java.util.concurrent.Callable;
public class CameraCaller implements Callable {
private CameraHandler cameraHandler;
public CameraCaller(CameraHandler ch){
cameraHandler = ch;
}
#Override
public Object call() throws Exception {
cameraHandler.takeAPic();
return true;
}
}
CameraHandler.java:.
package myTest.com.test;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.os.Environment;
import android.util.Log;
import junit.runner.Version;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class CameraHandler implements Camera.PictureCallback{
private Camera mCamera;
public CameraHandler(){
}
public Boolean takeAPic(){
try{
if (mCamera == null){
mCamera = Camera.open();
mCamera.enableShutterSound(false);
try {
mCamera.setPreviewTexture(new SurfaceTexture(10));
}
catch (IOException e1) {Log.e(Version.id(), e1.getMessage());
}
}
mCamera.startPreview();
mCamera.takePicture(null, null, this);
}
catch (Exception ex){ }
return true;
}
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
} catch (IOException e) { }
try {
Thread.sleep(2000);
}catch (Exception ex){}
}
public static File getOutputMediaFile() {
File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File mediaStorageDir = new File(file, "MyCameraApp");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
return mediaFile;
}
}

Writing more than one String to a file without deleting the first one ANDROID favorites for browser

I am making a simple browser for school and I am trying to make the favorites. This code here adds a favorite to a file(so I can keep it after the app is closed) and displays it in the TextView. My problem is that it can only save one. If i add the second one, the first one is replaced. I thought i could add them in an array or arrayList(or anything that works, i am open to suggestions), but i can't succeed. Thanks for the help.
package com.example.browser3;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Favorite extends Activity {
EditText etName;
EditText etAdress;
Button bAdd;
TextView tvDisplay;
protected void onResume() {
readFile("favorite.txt", tvDisplay);
super.onResume();
}
public void writeFile(String fileName, EditText v, EditText x){
try {
OutputStreamWriter out=new OutputStreamWriter(openFileOutput(fileName,0));
out.write(v.getText().toString()+ x.getText().toString());
out.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void readFile(String fileName, TextView w){
try {
InputStream in=openFileInput(fileName);
if(in!=null){
InputStreamReader reader= new InputStreamReader(in);
BufferedReader buffreader= new BufferedReader(reader);
StringBuilder builder= new StringBuilder();
String str;
while((str=buffreader.readLine())!=null){
builder.append(str+ "\n");
}
in.close();
w.setText(builder.toString());
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.favorite);
etName = (EditText) findViewById(R.id.etName);
etAdress = (EditText) findViewById(R.id.etAdress);
bAdd = (Button) findViewById(R.id.bAdd);
tvDisplay = (TextView) findViewById(R.id.tvDisplay);
bAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
writeFile("favorite.txt",etName, etAdress);
readFile("favorite.txt", tvDisplay);
}
});
}
}

to write at first position i.e. prepend then u need to use this
private void writeToFile(Context context,String data){
try{
String path=context.getFilesDir().getAbsolutePath();
File file = new File(path + File.separator + fileName);
RandomAccessFile rf = new RandomAccessFile(file,"rws");
file.getParentFile().mkdirs();
Log.d("creating file path",path);
byte[] text = new byte[(int) file.length()];
rf.readFully(text);
rf.seek(0);
rf.writeBytes(data);
rf.write(text);
Log.d("write","writing file...");
rf.close();
}catch(Exception e){e.printStackTrace(); Log.d("caught", "data wititng fail");}
}
and if u want to append use this
private void writeToFile(Context context,String data){
try{
String path=context.getFilesDir().getAbsolutePath();
File file = new File(path + File.separator + fileName);
RandomAccessFile rf = new RandomAccessFile(file,"rws");
file.getParentFile().mkdirs();
Log.d("creating file path",path);
byte[] text = new byte[(int) file.length()];
rf.readFully(text);
rf.seek(0);
rf.write(text);
rf.writeBytes(data);
Log.d("write","writing file...");
rf.close();
}catch(Exception e){e.printStackTrace(); Log.d("caught", "data wititng fail");}
}
or u can open file in MODE_APPEND mode.. to open file in append mode change to this OutputStreamWriter out=new OutputStreamWriter(openFileOutput(fileName,true));

android.app.SuperNotCalledException: Activity did not call through to super.onCreate()

Here is my Android Media player code. I don't know what I am missing in this code, when I run with breakpoint at line MediaPlayer mp = new MediaPlayer() in Debug mode. All the files in zip folder is played. But when I run the application in normal mode the first file is played and then I get this error:
android.app.SuperNotCalledException: Activity {com.example.mediaplayer/com.example.mediaplayer.MainActivity} did not call through to super.onCreate()
Code:
package com.example.mediaplayer;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import org.apache.commons.io.IOUtils;
import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.widget.Button;
public class MainActivity extends Activity {
private MediaPlayer mp;
private static final String MAIN_TAG ="ERROR";
#Override
protected void onCreate(Bundle savedInstanceState) {
try {
//final String file_loc= Environment.getExternalStorageDirectory().toString();
//Log.i("location",file_loc);
ZipFile zip = new ZipFile("/storage/emulated/0/AjeshDocument/sample.zip");
for(int i=1;i<7;i++){
ZipEntry entry = zip.getEntry("sample/rihanna_"+i+".mp3");
if (entry != null) {
InputStream in = zip.getInputStream(entry);
// see Note #3.
File tempFile = File.createTempFile("_AUDIO_", ".wav");
FileOutputStream out = new FileOutputStream(tempFile);
IOUtils.copy(in, out);
// do something with tempFile (like play it)
File f = tempFile;
try {
if (f.exists())
{
Log.i(MAIN_TAG,"Audio file found!");
MediaPlayer mp = new MediaPlayer();
FileInputStream fis = new FileInputStream(f);
mp.setDataSource(fis.getFD());
mp.prepare();
//mp.setLooping(false);
mp.start();
//mp.stop();
// mp.release();
Log.i(MAIN_TAG,"Pronounciation finished!");
}
else
{
Log.i(MAIN_TAG,"File doesn't exist!!");
}
}
catch (IOException e)
{
Log.i(MAIN_TAG,e.toString());
}
}
else {
// no such entry in the zip
}
} //for end
mp.release();
}
catch (Exception e) {
// handle your exception cases...
Log.i(MAIN_TAG,e.toString());
}
}
#Override
protected void onResume() {
Log.w("Info", "App Resume");
super.onResume();
}
#Override
protected void onStop() {
Log.w("Info", "App stopped");
super.onStop();
}
#Override
protected void onDestroy() {
Log.w("Info", "App destoryed");
super.onDestroy();
}
}

You didn't call the Activity's onCreate() method, i.e the super class' one. Add the call to MainActivity's onCreate() method:
public class MainActivity extends Activity {
private MediaPlayer mp;
private static final String MAIN_TAG ="ERROR";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); // this line is missing
// your code below ...