Develop Reference

How can I get the true path where my file is?

I want to know if a file exists. I have created it and stored with sharedPreferences, but Android doesn´t get me the true route.
public class SplashScreen extends AppCompatActivity
{
super.onCreate(SavedInstanceState);
setContentView(R.layout.activity_splash_screen);
String FILE_NAME = "configAjustes.xml";
new Handler().postDelayed(() -> {
File file1 = new File(getApplicationContext().getFilesDir().getPath(),FILE_NAME);
Log.d("fc","file1 is "+file1);
Log.d("fc","file1 name is "+file1.getName);
if(file1.exists())
{
Log.d("fc","exists");
Intent inMain = new Intent (getApplicationContext(),MainActivity.class);
startActivity(inMain);
finish();
}else
{
Log.d("fc","not exists");
Intent inSettings= new Intent(getApplicationContext(),Settings.class);
startActivity(inSettings);
finish();
}
},2000);
}
I get the following:
the problem is that the path that android gives me is not true, because the xml file is not in "files". It is in "shared_prefs"
How can I get the true path where my file is?

Normally, we do not think of SharedPreferences as a file, and there is no direct and reliable way to access them as a file.
The closest solution is:
File prefsDir = new File(getApplicationInfo().dataDir,"shared_prefs");
File file1 = new File(prefsDir, FILE_NAME);
Or possibly:
File dataDir = getFilesDir().getParentFile();
File prefsDir = new File(dataDir,"shared_prefs");
File file1 = new File(prefsDir, FILE_NAME);
However, there is no guarantee that these will work across all Android OS versions and all devices.

Storage in android studio

I am trying to pull multiple images from gallery and place in grid view , Unfortunately I am not able to do so, Can you help me with that. And also I made a folder in sd card and I m trying to store audio as well as photographs in the same folder. Can you help me with that as well?
I am using android 2.3.
So I have included this code inside the button click but on click of button it has created the folder but its not storing the file inside the folder. On click of the button every other thing is working, its opening the gallery and its calculating numpic. I am not sure why its not storing the file in CN Video folder.
public void onClick(View v) {
Intent pass_data = new Intent(MainRecord.this, OpenGallery.class);
pass_data.putExtra("numpic",numpic);
startActivity(pass_data);
// Saving Audio recorded file to directory
File f = new File(Environment.getExternalStorageDirectory() + "/CNvideo");
if(f.isDirectory()) {
//Write code for the folder exist condition
}else {
// create a File object for the parent directory
File CNvideoDirectory = new File("/sdcard/CNVideo/");
// have the object build the directory structure, if needed.
CNvideoDirectory.mkdirs();
// create a File object for the output file
String filename = getfilename();
File outputFile = new File(CNvideoDirectory, filename);
// now attach the OutputStream to the file object, instead of a String representation
try {
FileOutputStream fos = new FileOutputStream(outputFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}};

Android; Check if file exists without creating a new one

I want to check if file exists in my package folder, but I don't want to create a new one.
File file = new File(filePath);
if(file.exists())
return true;
Does this code check without creating a new file?

Your chunk of code does not create a new one, it only checks if its already there and nothing else.
File file = new File(filePath);
if(file.exists())
//Do something
else
// Do something else.

When you use this code, you are not creating a new File, it's just creating an object reference for that file and testing if it exists or not.
File file = new File(filePath);
if(file.exists())
//do something

It worked for me:
File file = new File(getApplicationContext().getFilesDir(),"whatever.txt");
if(file.exists()){
//Do something
}
else{
//Nothing
}

When you say "in you package folder," do you mean your local app files? If so you can get a list of them using the Context.fileList() method. Just iterate through and look for your file. That's assuming you saved the original file with Context.openFileOutput().
Sample code (in an Activity):
public void onCreate(...) {
super.onCreate(...);
String[] files = fileList();
for (String file : files) {
if (file.equals(myFileName)) {
//file exits
}
}
}

The methods in the Path class are syntactic, meaning that they operate on the Path instance. But eventually you must access the file system to verify that a particular Path exists
File file = new File("FileName");
if(file.exists()){
System.out.println("file is already there");
}else{
System.out.println("Not find file ");
}

public boolean FileExists(String fname) {
File file = getBaseContext().getFileStreamPath(fname);
return file.exists();
}

if(new File("/sdcard/your_filename.txt").exists())){
// Your code goes here...
}

Kotlin Extension Properties
No file will be create when you make a File object, it is only an interface.
To make working with files easier, there is an existing .toFile function on Uri
You can also add an extension property on File and/or Uri, to simplify usage further.
val File?.exists get() = this?.exists() ?: false
val Uri?.exists get() = File(this.toString).exists()
Then just use uri.exists or file.exists to check.

Error when call write()

I have error in line:
workbook.write();
When I try debug, i see massage: "Source not found."
How it fix?
private void exportExcel() throws IOException, WriteException{
File file = new File(Environment.getExternalStorageDirectory() + "/backup.xls");
WritableWorkbook workbook = Workbook.createWorkbook(file);
workbook.createSheet("worksheet", 0);
workbook.write();
workbook.close();
}
Thanks in advance
WTF my code above begin to work!!!
When I started, I using default jexcelapi. Afterwards I begin using alternative jexcelapi, but it also not work.
When I try your code with little changes - it work! Your code:
private void exportExcel() throws WriteException, IOException{
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File(sdCard + "/myFolder");
//make them in case they're not there
dir.mkdirs();
//create a standard java.io.File object for the Workbook to use
File wbfile = new File(dir, "backup.xls");
WritableWorkbook workbook = null;
try{
workbook = Workbook.createWorkbook(wbfile);
workbook.createSheet("worksheet", 0);
workbook.write();
workbook.close();
} catch (IOException ex) {
Log.e("Workbook Test", "Could not create " + wbfile.getPath(), ex);
}
}
But when I try my code above, it also work.
Maybe Eclipse not instantly update using library?
Thank you very much!
P.S. Excuse me for my bad english.

Your code does not check that the external storage directory is actually available. You need to call getExternalStorageState and check the return value against the various MEDIA_* values defined in Environment. If the directory is not available, that may cause the problem.
The problem also may be that you are trying to write to the root of the external storage directory. From the docs:
Applications should not directly use this top-level directory, in order to avoid polluting the user's root namespace. Any files that are private to the application should be placed in a directory returned by Context.getExternalFilesDir, which the system will take care of deleting if the application is uninstalled.
EDIT
Try this code:
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File(sdCard + "/myFolder");
//make them in case they're not there
dir.mkdirs();
//create a standard java.io.File object for the Workbook to use
File wbfile = new File(dir, "backup.xls");
try{
WritableWorkbook workbook = Workbook.createWorkbook(wbfile);
workbook.createSheet("worksheet", 0);
workbook.write();
workbook.close();
} catch (IOException ex) {
Log.e("Workbook Test", "Could not create " + wbfile.getPath(), ex);
}
return wb;
That should tell you more about what's going on.
EDIT 2
After a little more research, I found another possible issue: JExcelApi uses a lot of resources when it is creating a file. One solution is to use a temp file. Add the following code:
WorkbookSettings wbSettings = new WorkbookSettings();
wbSettings.setUseTemporaryFileDuringWrite(true);
and inside the try block, change the line that creates the workbook:
WritableWorkbook workbook = Workbook.createWorkbook(wbfile, wbSettings);

access android media directory?

ey up. ive built a simple music app that reads wav files from the sdcard and plays them.
how do i access the default media directory?
this is how i get the sdcard
public void LoadSounds() throws IOException
{
String extState = Environment.getExternalStorageState();
if(!extState.equals(Environment.MEDIA_MOUNTED)) {
//handle error here
}
else {
File sd = new File(Environment.getExternalStorageDirectory ()); //this needs to be a folder the user can access, like media
as usual the docs dont give an actual example of usage but it says this - If you're using API Level 8 or greater, use getExternalFilesDir() to open a File that represents the external storage directory where you should save your files. This method takes a type parameter that specifies the type of subdirectory you want, such as DIRECTORY_MUSIC...
how do i use it?
thank you
edit:
this makes it crash if i try to fill a spinner array with file path Strings.
File path = getExternalFilesDir(Environment.DIRECTORY_MUSIC);
File sd = new File(path, "/myFolder");
File[] sdDirList = sd.listFiles(new WavFilter());
if (sdDirList != null)
{
//sort the spinner
amountofiles = sdDirList.length;
array_spinner=new String[amountofiles];
......
final Spinner s = (Spinner) findViewById(R.id.spinner1); //crashes here
ArrayAdapter<?> adapter = new ArrayAdapter<Object>(this,
android.R.layout.select_dialog_item, array_spinner);
EDIT2:
ok so ive done this test that is supposed to write a txt file to the music directory.
i run the app, no txt file is written anywhere on the device i can find.
// Path to write files to
String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC).getAbsolutePath();
String fname = "mytest.txt";
// Current state of the external media
String extState = Environment.getExternalStorageState();
// External media can be written onto
if (extState.equals(Environment.MEDIA_MOUNTED))
{
try {
// Make sure the path exists
boolean exists = (new File(path)).exists();
if (!exists){ new File(path).mkdirs(); }
// Open output stream
FileOutputStream fOut = new FileOutputStream(path + fname);
fOut.write("Test".getBytes());
// Close output stream
fOut.flush();
fOut.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
another edit: i will get this working!!
so if i use this line it creates a folder on the sdcard called 'Musictest'. dont understand??
String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC + "test").getAbsolutePath();
////////////////////////////////////////////////////////////////////
Final Edit:
right so this will look for a folder called test in the devices music directory.
if it doesnt exist, it will be created.
(some fixing to be done here, error if empty) it then lists the files in the directory and adds them to an array.
public void LoadSounds() throws IOException
{
String extState = Environment.getExternalStorageState();
// Path to write files to
String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC + "/test").getAbsolutePath();
if(!extState.equals(Environment.MEDIA_MOUNTED)) {
//handle error here
}
else {
//do your file work here
// Make sure the path exists
boolean exists = (new File(path)).exists();
//if not create it
if (!exists){ new File(path).mkdirs(); }
File sd = new File(path);
//This will return an array with all the Files (directories and files)
//in the external storage folder
File[] sdDirList = sd.listFiles();
if (sdDirList != null)
{
//add the files to the spinner array
array_spinnerLoad=new String[sdDirList.length];
files = new String[sdDirList.length];
for(int i=0;i<sdDirList.length;i++){
array_spinnerLoad[i] = sdDirList[i].getName();
files[i] = sdDirList[i].getAbsolutePath();
}
}
}
}

as mentioned in the docs, getExternalFilesDir() return File. And File object can represent either file or directory.
Therefore:
File musicDirectory = new File( getExternalFilesDir(Environment.DIRECTORY_MUSIC));
Will give you the object to play with.