I am trying to test a simple file i/o program on android where i type in some text in
EditText and when i click the Save Button, it writes the content in a file. and when i click the Load button it loads the content back into the EditText.
here is my code---
public class Activity2 extends Activity {
private EditText textBox;
private static final int READ_BLOCK_SIZE = 100;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout2);
textBox = (EditText) findViewById(R.id.txtText1);
Button saveBtn = (Button) findViewById(R.id.btnSave);
Button loadBtn = (Button) findViewById(R.id.btnLoad);
saveBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String str = textBox.getText().toString();
try
{
PrintWriter PR=new PrintWriter(new File("text1.txt"));
PR.write(str);
PR.flush();
PR.close();
//textBox.setText("");
//---display file saved message---
Toast.makeText(getBaseContext(),
"File saved successfully!",
Toast.LENGTH_SHORT).show();
//---clears the EditText---
textBox.setText("");
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
}
});
loadBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
try
{
File f=new File("text1.txt");
BufferedReader BR=new BufferedReader(new FileReader(f));
String txt="";
String str;
while((str=BR.readLine())!=null)
{
txt+=str;
}
//---set the EditText to the text that has been
// read---
textBox.setText(txt);
BR.close();
Toast.makeText(getBaseContext(),
"File loaded successfully!",
Toast.LENGTH_SHORT).show();
}
catch (IOException ioe) {
ioe.printStackTrace();
}
}
});
}
}
`
why is it not working? Thanks in advance for any help. Any explanation would be highly appreciated.
Using new File("text1.txt") as output does not work on Android. The current working directoy is always / which is not writable for your app. Use
File f = new File(Environment.getExternalStorageDirectory(), "text1.txt");
getExternalStorageDirectory() is the internal storage for newer phones.
Your app Context has several paths that you can use if you want to store data in your app-private folder. Paths from Environment are in public places where you can simply read the data with a filemanager
And don't forget to add
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
in case you want to write to those public paths
Related
I have code (which can be seen below) which does not function correctly. I have tried literally every solution already presented on SO and i cannot find anything that will work for my problem.
The aim of my application is to get the Key Code (either numerical or represented as the label/"KEYCODE_A") and output this to a txt file. Regardless of the txt file aspect, i cannot even get the keycode to output to the log.
The only four keycodes that come from the stock android keyboard are:
KEYCODE_SHIFT_LEFT = 59
KEYCODE_SHIFT_RIGHT = 60
KEYCODE_ENTER = 66
KEYCODE_DEL = 67
Please can someone help me to be able to get the characters on the keyboard represented as a numerical value or otherwise to output to either the log, a field, or a text file.
I have tried numerous solutions such as
char unicodeChar = (char)event.getUnicodeChar();
try editText.setOnEditorActionListener
and they do not work.
Thank you in advance for your help!!!!!!!
public class MainActivity extends AppCompatActivity{
EditText et_name, et_content;
Button b_save;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1000);
}
et_name = (EditText) findViewById(R.id.et_name);
et_content = (EditText) findViewById(R.id.et_content);
final TextView view = (TextView) findViewById(R.id.view);
b_save = (Button) findViewById(R.id.b_save);
et_content.setOnKeyListener(new View.OnKeyListener(){
public boolean onKey(View v, int keyCode, KeyEvent event) {
// String keyCodeStr = KeyEvent.keyCodeToString(keyCode);
//view.setText(String.valueOf(keyCodeStr));
char unicodeChar = (char) event.getUnicodeChar();
Log.e("Key", "Code "+keyCode + " " + unicodeChar);
et_content.getText().append(unicodeChar);
return true;
}
});
b_save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String filename = et_name.getText().toString();
String content = et_content.getText().toString();
saveTextAsFile(filename, content);
}
});
}
private void saveTextAsFile (String filename, String content){
String fileName = filename + ".txt";
//create file
File file = new File (Environment.getExternalStorageDirectory().getAbsolutePath(), fileName);
//write to file
try {
FileOutputStream fos = new FileOutputStream(file);
fos.write(content.getBytes());
fos.close();
Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e){
e.printStackTrace();
Toast.makeText(this, "File not found", Toast.LENGTH_SHORT).show();
} catch (IOException e){
e.printStackTrace();
Toast.makeText(this, "Error saving", Toast.LENGTH_SHORT).show();
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
switch (requestCode){
case 1000:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "Permission Granted", Toast.LENGTH_SHORT).show();
} else{
Toast.makeText(this, "Permission Not Granted", Toast.LENGTH_SHORT).show();
finish();
}
}
}
}
Thank you for your help!
Any more info needed please let me know, but i'm very desperate to get this fixed!
Soft keyboards rarely if ever send key codes. They tend to send text directly via commitText() calls on the input connection. They just don't work on the old "send hardware key event" model you want them to, there's no way to do what you're trying.
You can try creating your own custom input connection and working on that level. But my guess is you'll have a lot of issues dealing with the predictive capabilities of the keyboard and composing text (a concept where part of the text is temporary and is overwritten by the next send of any text). And the fact that it may send whole words at a time rather than letters/keystrokes
This is my first android app so I am quite new to it. I am able to read from a property file but facing problem on writing back to it on the save button in the same activity.
Here is my code
public class ConfigurationActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_configuration);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final EditText abc = (EditText) findViewById(R.id.abc);
...
...
...
//Reading into a activity and displaying it into the user
try {
Properties props = new Properties();;
InputStream inputStream = getApplicationContext().getAssets().open("app.properties");
props.load(inputStream);
abc.setText(props.getProperty("abc"));
...
...
...
inputStream.close();
} catch (FileNotFoundException ex) {
Log.e("Exception", "File donot exists");
} catch (IOException ex) {
Log.e("Exception","IO error");
}
//On the save button I am trying to write back to properties file
Button save = (Button) findViewById(R.id.SaveButton);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
Properties props = new Properties();
props.setProperty("abc", abc.getText().toString());
...
...
...
props.store(getApplicationContext().getAssets().openFd("app.properties").createOutputStream(), null);
Intent intent = new Intent(ConfigurationActivity.this, MainActivity.class);
startActivity(intent);
finish();
//inputStream.close();
} catch (FileNotFoundException ex) {
Log.e("Exception", "File donot exists");
} catch (IOException ex) {
Log.e("Exception","IO error");
}
}
});
}
}
Now I am getting the data from the property file and displaying it to user but on the save button its giving FileNotFoundException. I looked for other codes on stackoverflow but I wasn't able to solve my problem
Can someone guide my in this ?
Thanks in advance
You cannot modify assets or resources at runtime. They are read-only.
I'm trying to write the stream of my array that is coming from Bluetooth module and read from (HandleRead), to the internal storage directly. Is that possible in the first place?
Note that I am reading 100 samples per second. That means the file will fill up quickly. I am not familiar with storage, and my code isn't executed as I expected.
public class MainActivity extends ActionBarActivity implements SensorEventListener {
File Root = Environment.getExternalStorageDirectory();
File Dir = new File (Root.getAbsolutePath()+"/myAppFile");
File file = new File(Dir,"Message.txt");
#Override
protected void onCreate(Bundle savedInstanceState){
String state;
state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)){
if (!Dir.exists()){
Dir.mkdir();
}
}
private void handleRead(Message msg) {
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf);
ByteBuffer buffer = ByteBuffer.wrap(readBuf, 0, readBuf.length);
buffer.order(ByteOrder.BIG_ENDIAN);
buffer.clear();
final String[] strNumbers = readMessage.split("\n");
for (int j = 1; j <= strNumbers.length - 2; j++) {
pressure = Integer.parseInt(readMessage2);
MyFinalPressure = (float) (9.677 +0.831 * pressure);
// trying to store directly to internal sotrage
activity.save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
FileOutputStream fileOutputStream = new FileOutputStream(activity.file);
fileOutputStream.write((int) MyFinalPressure);
fileOutputStream.close();
Toast.makeText(activity.getApplicationContext(),"Message saved ", Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e){
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}
}
}
It appears you are not setting the FileOutputStream to 'append' (you need to add 'true' as 2nd parameter in constructor.)
This would write over the file from the file-start every time
also your 'setOnClickListener' is INSIDE your loop. This doesn't do anything for you as far as I can tell.
I recommend always setting up UI elements in a private void setupUI() {...} method that onCreate calls. The public void onClick(View v) {buttonForSavingPresssed()} where buttonForSavingPressed(){...} is the 'logic' of your onClick() method.
This will help you clean up the class and not have stray onClickListener assignments, etc.
My guess is that either your multiple assignments is very inefficient, since clickListeners aren't cheap, or... the clickListener might not even work at all because of a timing issue (if your loop is long running and you press the button and the listener has already been swapped for a new one)
I've cleaned up your code some, There are some suggestions and some log statements that should help you figure out what is going on.
// this is inside your onCreate()
...
activity.save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) { buttonPressed();}
});
...
// Here is where you would put your logic when the button is presssed
public void buttonPressed(){
Toast.makeText(activity.getApplicationContext(),"Button Pressed ",
Toast.LENGTH_SHORT).show();
}
// you should make 'helper' functions that consolidate separate pieces of logic like this,
// that way you can more easily track what is happening in each method.
// Plus it helps keep each method shorter for ease of understanding, etc.
public void writeToFile(float finalPressure){
Log.d(LOG_TAG // where LOG_TAG is the String name of this class
"writeToFile(float) called." );
try{
// true here for 'append'
FileOutputStream fileOutputStream = new
FileOutputStream(activity.file, true);
fileOutputStream.write((int) finalPressure);
fileOutputStream.close();
}catch (FileNotFoundException e){
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
// now back to your handleRead, is this method called async wenever
// a message is read? Then wouldn't this be called a lot? I'm lost as to why
// you had the button in here at all.
private void handleRead(Message msg) {
Log.d(LOG_TAG // where LOG_TAG is the String name of this class
"handleRead(Message) called." );
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf);
ByteBuffer buffer = ByteBuffer.wrap(readBuf, 0, readBuf.length);
buffer.order(ByteOrder.BIG_ENDIAN);
buffer.clear();
final String[] strNumbers = readMessage.split("\n");
Log.d(LOG_TAG // where LOG_TAG is the String name of this class
"strNumbers length: " + strNumbers.length );
for (int j = 1; j <= strNumbers.length - 2; j++) {
pressure = Integer.parseInt(readMessage2);
MyFinalPressure = (float) (9.677 +0.831 * pressure);
// trying to store directly to internal sotrage
writeToFile(MyFinalPressure);
}
}
I have an application that saves data to a file called 'sensorLog.txt'. I am not sure where exactly this is stored but I know this is only accessible by the applicationand it is in the internal memory.
I want to be able to write a copy the current file to an external storage when I click on a button "export". I have pasted a small bit of my program, But i am not sure how to copy sensorLog.txt file to the external storage.
public class MainActivity extends Activity {
private static final String DEBUG_TAG = "MainActivity";
private Button buttonStartService;
private Button buttonStopService;
private Button buttonSettings;
private Button buttonExport;
private TextView textStatus;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Context context = getApplicationContext();
setContentView(R.layout.activity_main);
buttonStartService = (Button) findViewById(R.id.button_start_service);
buttonStopService = (Button) findViewById(R.id.button_stop_service);
buttonSettings = (Button) findViewById(R.id.button_settings);
buttonExport = (Button) findViewById(R.id.button_export);
textStatus = (TextView) findViewById(R.id.text_status);
buttonStartService.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
startSensorService();
}
});
buttonStopService.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
stopSensorService();
}
});
//export button listener
buttonExport.setOnClickListener(export_handler);
}
public void startSensorService() {
// Schedule
AlarmManager scheduler = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(getApplicationContext(), SensorService.class);
PendingIntent scheduledIntent = PendingIntent.getService(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
// 30 seconds
long interval = 30 * 1000;
scheduler.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), interval, scheduledIntent);
Log.d(DEBUG_TAG, "Service started");
}
public void stopSensorService() {
// Cancel
AlarmManager scheduler = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(this, SensorService.class);
PendingIntent scheduledIntent = PendingIntent.getService(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
scheduler.cancel(scheduledIntent);
Log.d(DEBUG_TAG, "Service stopped");
}
View.OnClickListener export_handler = new View.OnClickListener() {
public void onClick(View v)
{
// Here is the part I am not sure what to do. I want to copy a file sensorLog.txt that has all my sensor information to sd card
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state))
{
Log.d(DEBUG_TAG, "SD card detected");
stopSensorService();
File file = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_DOCUMENTS),"SensorLog.txt");
// delete file from the internal storage once exported
context.deleteFile("SensorLog.txt");
startSensorService();
}
else
{
Log.d(DEBUG_TAG, "No external storage detected(cannot copy file)");
}
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
Part where I create sensorLog.txt***(I dont think it is necessary to read for this question but just in case someone needs it)*:
private class SensorServiceLoggerTask extends AsyncTask<SensorFrame, Void, Void> {
#Override
protected Void doInBackground(SensorFrame... frames) {
SensorFrame frame = frames[0];
BufferedWriter bufWr = null;
try {
File file = new File(getApplicationContext().getFilesDir(), "SensorLog.txt");
if (file.exists()) {
// Write to new file
bufWr = new BufferedWriter(new FileWriter(file, true));
} else {
file.createNewFile();
Log.d(DEBUG_TAG, "New log file created");
// Append to existing file
bufWr = new BufferedWriter(new FileWriter(file, false));
// Write header
bufWr.append(sensorHeader.toString());
}
// Write frame
bufWr.append(sensorFrame.toString());
bufWr.flush();
Log.d(DEBUG_TAG, "Added frame to log");
} catch (IOException ex) {
// TODO: useful error handling
} finally {
// Cleanup
if (bufWr != null) {
try {
bufWr.close();
} catch (IOException ex) {
// TODO: useful error handling
}
}
}
return null;
}
}
I also have 2 more queries:
Lets say I want to append some information at the top of the file just before moving it how can I do that?
My aim is to transfer the sensorLog.txt file from internal to external storage when the export button is pressed. delete or empty the internal sensorLog.txt file and then the same thing happens again if i press export again, then I would have to rename my file when I export it right? would there not be a name clash? How do I handle that? could I give a name dynamically?
Thank you.
EDIT: Some corrections
View.OnClickListener export_handler = new View.OnClickListener() {
public void onClick(View v)
{
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state))
{
Log.d(DEBUG_TAG, "SD card detected");
stopSensorService();
Log.d(DEBUG_TAG, "stopSensorService for file transfer");
//make the timestamp the file name
long TS = System.currentTimeMillis();
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(TS);
stringBuilder.append(".txt");
String file_name = stringBuilder.toString();
//file name stored in file_name
File file_ext = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_DOCUMENTS),file_name);
// attempt to create this new directory
//read from sensorLog.txt file
try
{
file_ext.createNewFile();
File file = getBaseContext().getFileStreamPath("sensorLog.txt");
if(file.exists())
{
FileInputStream read_file = openFileInput("sensorLog.txt");
//read contents of internal file
InputStreamReader inputStreamReader = new InputStreamReader(read_file);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
StringBuilder sb = new StringBuilder();
sb.append("Timestamp of export to SD"+TS+"/n");
String line;
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
BufferedWriter bufWr = null;
bufWr = new BufferedWriter(new FileWriter(file_ext, false));
// Write header
bufWr.append(sb.toString());
inputStreamReader.close();
bufWr.close();
read_file.close();
//delete sensor file once exported
getApplicationContext().deleteFile("sensorLog.txt");
}
}
catch(Exception e){}
But for some reason my file is not getting stored in the SD card.
Check out the Android documentation. If you can read your sensorLog.txt file, then you can save it in a String and then save the string to a file in the external storage.
I am downloading a file from ftp server. downloading code worked fine, however after download code screen doesn't show anything ,it gets black. Also download function is not returning true value, even the file is being saved in the specified directory.
public class FTPClass{
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_file_player);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
Intent intent = getIntent();
dirname = intent.getStringExtra("currentDirName");
MyFTPClient mftp = new MyFTPClient();
createPath = mftp.getAppRootPath().concat("/"+ dirname);
mftp.setCurrentDir(createPath);
System.out.println(mftp.ftpChangeDirectory(createPath));
FTPFile[] farr = mftp.ftpListAllFiles();
System.out.println(farr.length);
for(int i = 0; i<farr.length;i++){
System.out.println("SRC: "+createPath+"/"+farr[i].getName());
String src = createPath+"/"+farr[i].getName();
System.out.println("DEST: "+"/data/data/com.example.ftpplayer" + "/app_"+dirname);
String dest ="/data/data/com.example.ftpplayer" + "/app_"+dirname+"/"+farr[i].getName();
System.out.println(mftp.downloadFile(src,dest));
}
}
}
public class CallingIntent extends Activity{
System.out.println("In item click ");
Intent intent = new Intent(getApplicationContext(), FTPClass.class);
String dir = ((TextView) view).getText().toString();
intent.putExtra("currentDirName", dir);
startActivity(intent);
}
public class MyFTPClient{
public boolean downloadFile(String srcPath , String destPath){
try {
FileOutputStream fos = new FileOutputStream(destPath);
System.out.println(mftp.retrieveFile(srcPath, fos)); // retrieve file doesn't return true
fos.flush();
fos.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}
return false;
}
}
You need to run your code on the background thread, try using an asyncTask.