I want to build a TXT file and add new lines to it every time.
I don't want it to be in the app data folder in external storage (default folder used in openFileOutput()) since it's erased as the app uninstalled (This is a log meant for these issues).
How can it be done ?
Use FileWriter. The constructor's second argument defines whether an existing file should be opened and appended.
FileWriter writer;
try {
writer = new FileWriter(yourFilePathHere, true);
writer.write("Hello World");
writer.flush();
writer.close();
} catch (IOException e) {
//Error handling
}
yourFilePathHere might be new File(getExternalStorageDirectory(), "log.txt").getAbsolutePath();
Related
I have written a method which creates a file and writes data to the file and stores in the internal storage. When I get the absolute path or path of the file [I have added log messages to experiment with the operations on the File], it shows me that the file is getting created under the root directory and its under the /data/data/mypackagename/files/filename.txt. Nevertheless, I could find these folders on the DDMS where I could find the file which has been created by the method which I have written. But I am unable to open that file too as I don't have permissions.
When I look at my Android device, I can't find these directories. I looked up on stack overflow and some have answered that the /data/data folders in the internal storage are hidden and to access them I have to root the device which I don't want to do.
Next approach: There is a folder called as MyFiles on the android device [I am using Galaxy Tab 4 running Android 4.4 for testing]. Under this folder there is Device Storage directory which has various folders like Documents, Pictures, Music, Ringtones, Android, etc, etc.. So, the apps like camera, spread sheet apps, are able to write or save pictures into the pictures folder or txt files in the documents folder. Similarly, how could I write the file which I am creating in the function to the Documents folder or any other folder which could be accessible over the device. Please help me how could I do it, any help is appreciated.
The following is the code which I have written:
public void addLog(String power_level){
// creates a logFile in the root directory of the internal storage of the application.
// If the file does not exists, then it is created.
Log.d("AppendPower", "In addLog method");
//File logFile = new File(((Context)this).getFilesDir(), "logFile.txt");
File logFile = new File(getFilesDir(), "logFile.txt");
Log.d("FilesDir Path", getFilesDir().getAbsolutePath());
Log.d("FilesDir Name", getFilesDir().getName());
Log.d("Path on Android", logFile.getPath());
Log.d("Absolute Path on Android", logFile.getAbsolutePath());
Log.d("Parent", logFile.getParent());
if(!logFile.exists()){
try{
logFile.createNewFile();
}catch(IOException io){
io.printStackTrace();
}
}
try{
BufferedWriter writer = new BufferedWriter(new FileWriter(logFile, true));
writer.write("Battery level reading");
writer.append(power_level);
Log.d("Power_Level in try", power_level);
writer.newLine();
writer.close();
}catch(IOException e){
e.printStackTrace();
}
}
As you have figured out writing to root directories in Android is impossible unless you root the device. Thats why even some apps in Play-store asking for root permissions before installing the app. Rooting will void your warranty so i don't recommend it if you don't have serious requirement.
Other than root directories you can access any folder which are visible in your Android file manager.
Below is how you can write into sd with some data - Taken from : https://stackoverflow.com/a/8152217/830719
Use these code you can write a text file in SDCard along with you need to set permission in android manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
this is the code :
public void generateNoteOnSD(String sFileName, String sBody){
try
{
File root = new File(Environment.getExternalStorageDirectory(), "Notes");
if (!root.exists()) {
root.mkdirs();
}
File gpxfile = new File(root, sFileName);
FileWriter writer = new FileWriter(gpxfile);
writer.append(sBody);
writer.flush();
writer.close();
Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show();
}
catch(IOException e)
{
e.printStackTrace();
importError = e.getMessage();
iError();
}
}
.
1) If your purpose is debugging, you may just write to the /sdcard/. It always works.
2) Again, if your purpose is debugging, you may try to set read permissions on your app's directories. A while ago it worked for me on some Android devices (but did not work on at least one device).
Add this permission in your AndroidManifest.xml file:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Then use this shortest recipe:
try
{
FileOutputStream fos =
openFileOutput("myfile.txt", getApplicationContext().MODE_PRIVATE);
fos.write("my text".getBytes());
fos.close();
}
catch (Exception exception)
{
// Do something, not just logging
}
It will be saved in "/data/data/my.package.name/files/" path.
I'm trying to create a .csv file in an android app. The app is supposed to create the file if there is none, or replace the file if it already exist. I tried to use the FileWriter, but it doesn't create the file and throws the 'FileNotFoundException: open failed: EROFS' exception.
I've already done some research, but I really can't find it. I have the permission in the manifest file (<uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />) and the app folder is not open in any other app.
(I know there is opencsv, but since this is the only thing I need to do, I don't think I really need it.)
Here's my code:
FileWriter writer;
try {
writer = new FileWriter("data.csv");
for(Answer answer: answerList) {
writer.append(answer.getName());
writer.append(',');
writer.append(answer.getTime());
writer.append('\n');
}
writer.flush();
writer.close();
}
catch (Exception e) {
e.printStackTrace();
}
Thank you!
Change
writer = new FileWriter("data.csv");
to
writer = new FileWriter(getFilesDir()+File.separatorChar+"data.csv");
This will create the file in the internal storage.
You need to give the full path to where you want to create the file or where it exists already.
Okay, I seem to be having a small issue with R.drawable.balloons. I'm trying to use a template for building a private external storage file that I found on Android Developer, but balloons keeps giving an error (cannot be resolved or is not a field). I was wondering if I could get some help fixing it.
Here's the code section it sits in:
void createExternalStoragePrivateFile() {
// Create a path where we will place our private file on external
// storage.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
try {
/*
Very simple code to copy a picture from the application's
resource into the external file. Note that this code does
no error checking, and assumes the picture is small (does not
try to copy it in chunks). Note that if external storage is
not currently mounted this will silently fail.
*/
// Creates file to stream picture
OutputStream os = new FileOutputStream(file);
// Allows app to accept the picture
InputStream is = getResources().openRawResource(R.drawable.balloons);
byte[] data = new byte[is.available()];
is.read(data);
os.write(data);
is.close();
os.close();
} catch (IOException e) {
// Unable to create file, likely because external storage is
// not currently mounted.
Log.w("ExternalStorage", "Error writing " + file, e);
}
}
A heads up, in case I get called out for being a copy/paster, this is only supposed to be a template, but I would like to test that it works before I make changes. Sorry.
You need an image named balloons in the res\drawable folder of your project (or any of its variants, such as drawable-hdpi, &c). The R class is autogenerated.
See How do I add R drawable android?
I'm running some tests using Robotium on an Android application that interacts with a web-portal.
I'd like to save some information to file; for example I need to save the id of the username I created from the app and I want to make it read from Selenium to run tests on web-portal to verify a webpage for that user has been created.
Is it possible?
Could someone suggest me a solution or a work-around?
This is an example of code, but it doesn't work (I want to write to a file for example on c:\myworkspace\filename.txt a string):
public void test_write_file(){
if(!solo.searchText("HOME")){
signIn("39777555333", VALID_PASSWORD);
}
try {
String content = "This is the content to write into file";
File file = new File("filename.txt");
// if file doesnt exists, then create it
if (!file.exists()) {
file.createNewFile();
}
FileWriter fw = new FileWriter(file.getAbsoluteFile());
BufferedWriter bw = new BufferedWriter(fw);
bw.write(content);
bw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
assertTrue(solo.searchText("HOME"));
}
This code should write to file on device; my goal is to write on a file on machine from which I'm launching the script; the application under test should have permission to write to memory card; but I ask how to go out from Android Environment and get my Desktop environment.
For tests I suppose you will need xml format to be saved: Create xml file and save it in internal storage android
And then you will need to copy saved file from your device, see this How to copy selected files from Android with adb pull
You could be not so lazy and search it yourself.
For reading from a file or writing to file you would have to use normal java method. There you can create a separate method to read/write, which can be called whenever needed. you can see examples here for normal text file and excel file.
First: see my question Reading XML online and Storing It (Using Java). Read the approved answers and the comments underneath that answer.
So, what my question here is: even though I've run through the process described in the linked question, and the .xml file saves to the /res/values folder in my Android App, its not showing up at all - not when I'm running the app, nor after I close the app.
Does anyone have any ideas on how to fix this so that when I generate the file, it will be available right away, even while the app is running, to read and use?
just use this code,
FileOutputStream fOut = null;
try {
fOut = this.openFileOutput("your xml file name.xml", MODE_PRIVATE);
try {
InputStream is = new FileInputStream("your source file");
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
fOut.write(buffer);
} catch(Exception e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
try {
fOut.close();
} catch (IOException e) {
e.printStackTrace();
}
}
and you can see your xml file at the data/data/packagename/file folder Thnx. Hope this will help you.
I'm not 100% sure if you're running the XML parsing in Java or actually in your Android app.
If you're running in Java, be aware that your project structure isn't live in the emulator - the .apk was packaged up and installed before running. You need to use adb to push files into the emulator (or your Android device) before your app can see the file.
If you're accessing the file in the app:
If you use file access methods such as openFileOutput() it will show up in the private directory on the device, which would be /data/data//files/
However, if you're using "new File(" rather than "context.openFileOutput" then the file is wherever you put it.