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How to create File object from assets folder?

I am trying to read a pdf file from my assets folder but I do not know how to get the path of pdf file.
I right click on pdf file and select "copy Path" and paste it
Here is the another screen shot of my code:
Here is my code:
File file = new File("/Users/zulqarnainmustafa/Desktop/ReadPdfFile/app/src/main/assets/Introduction.pdf");
if (file.exists()){
Uri path = Uri.fromFile(file);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(path, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try {
this.startActivity(intent);
}
catch (ActivityNotFoundException e) {
Toast.makeText(this, "No application available to view PDF", Toast.LENGTH_LONG).show();
}
}else{
Toast.makeText(this, "File path not found", Toast.LENGTH_LONG).show();
}
I always get file not found, Help me to create File object or let me know how I can get the exact path for a file I also tried with file:///android_asset/Introduction.pdf but no success. I also tried with Image.png but never gets file.exists() success. I am using Mac version of Android studio. Thanks

get input stream from asset and convert it to a file object.
File f = new File(getCacheDir()+"/Introduction.pdf");
if (!f.exists())
try {
InputStream is = getAssets().open("Introduction.pdf");
byte[] buffer = new byte[1024];
is.read(buffer);
is.close();
FileOutputStream fos = new FileOutputStream(f);
fos.write(buffer);
fos.close();
} catch (Exception e) { throw new RuntimeException(e); }

Short converter (storing asset as cache file) in Kotlin:
fun fileFromAsset(name: String) : File =
File("$cacheDir/$name").apply { writeBytes(assets.open(name).readBytes()) }
cacheDir is just shorthand for this.getCacheDir() and should be predefined for you.

Can you try this code
AssetManager am = getAssets();
InputStream inputStream = am.open("Indroduction.pdf");
File file = createFileFromInputStream(inputStream);
private File createFileFromInputStream(InputStream inputStream) {
try{
File f = new File("new FilePath");
OutputStream outputStream = new FileOutputStream(f);
byte buffer[] = new byte[1024];
int length = 0;
while((length=inputStream.read(buffer)) > 0) {
outputStream.write(buffer,0,length);
}
outputStream.close();
inputStream.close();
return f;
}catch (IOException e) {
//Logging exception
}
return null;
}
Then try with
File file = new File("new file path");
if (file.exists())

android-copying database from asset to sdcard -open failed: EISDIR (Is a directory)

this is my code for copying database from asset folder to SD card:
File databaseFile = new File(context.getExternalFilesDir(null),"");
if(!databaseFile.exists()){
databaseFile.mkdirs();
}
String outFileName = context.getExternalFilesDir(null) + "/db.db";
try {
OutputStream myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
InputStream myInput = context.getAssets().open("db");
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myInput.close();
myOutput.flush();
myOutput.close();
} catch (Exception e) {
Log.v("this",e.getMessage().toString());
}
when I run it ,it gives me this error :
/storage/emulated/0/Android/data/myPackageName/files/db.db: open failed: EISDIR (Is a directory)
How can I solve this ?
I've read this topic but didn't work :
FileOutputStream crashes with "open failed: EISDIR (Is a directory)" error when downloading image
also ,I test it on read device, the same error
thank you

I cannot get the full picture from the log line you have attached.
Still, if I had to guess, your problem is probably here:
if(!databaseFile.exists()){
databaseFile.mkdirs();
}
Remember: mkdirs() takes the entire path param you pass it, breaks it and, if needed, creates new folders.
mkdirs() cannot tell a file from a directory
So, if you invoke it like this:
databaseFile.mkdirs("/sdcard/rootDir/resDir/myImage.png");
It will create a folder named myImage.png.
Please check your code and change if needed.

This is the code I'm using to copy all files in assets to a sdcard. It's a asynch task so you want to implement some kind of respond method to know when the code is done and the db is useable.
The variable maindir is the folder location that you're copying to
and remember to give promissions in manifest file
public class copyEveStaticDataDump extends AsyncTask<String,Void,String> {
private Context context;
private String url,filename;
private String maindir;
public copyEveStaticDataDump(Context contextt,String maindir) {
super();
this.context = contextt;
this.maindir = maindir;
}
#Override
protected String doInBackground(String... params) {
copyFilesToSdCard();
return null;
}
private void copyFilesToSdCard() {
copyFileOrDir(""); // copy all files in assets folder in my project
}
private void copyFileOrDir(String path) {
AssetManager assetManager = context.getAssets();
String assets[] = null;
try {
Log.i("tag", "copyFileOrDir() "+path);
assets = assetManager.list(path);
if (assets.length == 0) {
copyFile(path);
} else {
String fullPath = maindir;
Log.i("tag", "path="+fullPath);
File dir = new File(fullPath);
if (!dir.exists() && !path.startsWith("images") && !path.startsWith("sounds") && !path.startsWith("webkit"))
if (!dir.mkdirs())
Log.i("tag", "could not create dir "+fullPath);
for (int i = 0; i < assets.length; ++i) {
String p;
if (path.equals(""))
p = "";
else
p = path + "/";
if (!path.startsWith("images") && !path.startsWith("sounds") && !path.startsWith("webkit"))
copyFileOrDir( p + assets[i]);
}
}
} catch (IOException ex) {
Log.e("tag", "I/O Exception", ex);
}
}
private void copyFile(String filename) {
AssetManager assetManager = context.getAssets();
InputStream in = null;
OutputStream out = null;
String newFileName = null;
try {
Log.i("tag", "copyFile() "+filename);
in = assetManager.open(filename);
if (filename.endsWith(".jpg")) // extension was added to avoid compression on APK file
newFileName = maindir + filename.substring(0, filename.length()-4);
else
newFileName = maindir+"/" + filename;
out = new FileOutputStream(newFileName);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e) {
Log.e("tag", "Exception in copyFile() of "+newFileName);
Log.e("tag", "Exception in copyFile() "+e.toString());
}
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
}
}

FileNotFoundException while copying data to SD Card - Android

Following is the code which I use to copy a folder containing a txt file. The folder resides in assets folder of my application. While I copy , I get File not found exception in the line out = new FileOutputStream(newFileName);
I get this working perfectly, when I save this to /data/data folder; ie; internal memory. I have checked the SD card state and it shows mounted.
public class CpyAsset extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
copyFileOrDir("edu1");//directory name in assets
}
File sdCard = Environment.getExternalStorageDirectory();
private void copyFileOrDir(String path) {
AssetManager assetManager = this.getAssets();
String assets[] = null;
try {
assets = assetManager.list(path);
if (assets.length == 0) {
copyFile(path);
} else {
File dir = new File (sdCard.getAbsolutePath());
if (!dir.exists()){
System.out.println("Created directory"+sdCard.getAbsolutePath());
boolean result = dir.mkdir();
System.out.println("Result of directory creation"+result);
}
for (int i = 0; i < assets.length; ++i) {
copyFileOrDir(path + "/" + assets[i]);
}
}
} catch (IOException ex) {
System.out.println("Exception in copyFileOrDir"+ex);
}
}
private void copyFile(String filename) {
AssetManager assetManager = this.getAssets();
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
String newFileName = sdCard.getAbsolutePath() + "/"+filename;
out = new FileOutputStream(newFileName);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e) {
System.out.println("Exception in copyFile"+e);
}
}
}
Exception
01-01 06:13:34.783: INFO/System.out(11334): Exception in copyFilejava.io.FileNotFoundException: /mnt/sdcard/edu1/anees.txt: open failed: ENOENT (No such file or directory)
The folder(and the content) I try to copy is in assets/edu1/abc.txt
Can someone please let me know what causes this as I cannot find any obvious reasons for the same? Any help is much appreciated.

You are always trying to create the external storage root dir in this part:
File dir = new File (sdCard.getAbsolutePath());
if (!dir.exists()){
System.out.println("Created directory"+sdCard.getAbsolutePath());
boolean result = dir.mkdir();
System.out.println("Result of directory creation"+result);
}
so you are not creating the folder edu1/ and the creation of the file anees.txt in that folder will fail.

in your code you check if the sdcard path is exist while you should check for your path which result in the dir "edu1" is never created try use this instead
File dir = new File (sdCard.getAbsolutePath()+"/"+path);

Try it out this way.......
File f = new File("/sdcard/assets/edu1/abc.txt");
FileWriter fw = new FileWriter(f);
BufferedWriter bw = new BufferedWriter(fw);

Copy directory ,sub directories and files to sd card - android

I use the following code to copy a particular directory and its contents to the sd card. The directory is placed inside res/raw folder.
Following is the code I use:
public class CopyActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
copyFilesToSdCard();
}
static String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
final static String TARGET_BASE_PATH = extStorageDirectory+"/Android/data/";
private void copyFilesToSdCard() {
copyFileOrDir("");
}
private void copyFileOrDir(String path) {
AssetManager assetManager = this.getAssets();
String assets[] = null;
try {
Log.i("tag", "copyFileOrDir() "+path);
assets = assetManager.list(path);
if (assets.length == 0) {
copyFile(path);
} else {
String fullPath = TARGET_BASE_PATH + path;
Log.i("tag", "path="+fullPath);
File dir = new File(fullPath);
if (!dir.exists())
if (!dir.mkdirs());
Log.i("tag", "could not create dir "+fullPath);
for (int i = 0; i < assets.length; ++i) {
String p;
if (path.equals(""))
p = "";
else
p = path + "/";
copyFileOrDir( p + assets[i]);
}
}
} catch (IOException ex) {
Log.e("tag", "I/O Exception", ex);
}
}
private void copyFile(String filename) {
AssetManager assetManager = this.getAssets();
InputStream in = null;
OutputStream out = null;
String newFileName = null;
try {
Log.i("tag", "copyFile() "+filename);
in = assetManager.open(filename);
if (filename.endsWith(".jpg")) // extension was added to avoid compression on APK file
newFileName = TARGET_BASE_PATH + filename.substring(0, filename.length()-4);
else
newFileName = TARGET_BASE_PATH + filename;
out = new FileOutputStream(newFileName);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e) {
Log.e("tag", "Exception in copyFile() of "+newFileName);
Log.e("tag", "Exception in copyFile() "+e.toString());
}
}
}
exception:
Exception in copyFile() of /mnt/sdcard/Android/data/raw/edu/anees.txt
Exception in copyFile() java.io.FileNotFoundException:
/mnt/sdcard/Android/data/raw/edu/anees.txt: open failed: ENOENT (No such file or directory)
Can someone please let me know what causes this issue and solution for the same.
ref: How to copy files from 'assets' folder to sdcard?
EDIT
I could resolve the exception with one of the tips regarding permission which was posted as one answer here.
Now I encounter another issue which is as follows:
The following log says I cannot create a folder in the following path:
Log.i("tag", "could not create dir "+fullPath);// fullPath = /mnt/sdcard/Android/data/raw
I do not want to have the data stored inside /mnt/sdcard/Android/data/raw, but instead, I want to have the contents of the raw folder inside assets to be copied to the path /mnt/sdcard/Android/data which is not happening with the piece of code I use from the reference link I gave. Any obvious reasons that might cause this with the code I gave?

You might have forgotten to set the permission in your manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Simple export and import of a SQLite database on Android

I am trying to implement a simple SQLite export/import for backup purposes. Export is just a matter of storing a copy of the raw current.db file. What I want to do for import is to just delete the old current.db file and rename the imported.db file to current.db. Is this possible? When I try this solution, I get the following error:
06-30 13:33:38.831: ERROR/SQLiteOpenHelper(23570):
android.database.sqlite.SQLiteDatabaseCorruptException: error code 11: database disk image is malformed
If I look at the raw database file in a SQLite browser it looks fine.

I use this code in the SQLiteOpenHelper in one of my applications to import a database file.
EDIT: I pasted my FileUtils.copyFile() method into the question.
SQLiteOpenHelper
public static String DB_FILEPATH = "/data/data/{package_name}/databases/database.db";
/**
* Copies the database file at the specified location over the current
* internal application database.
* */
public boolean importDatabase(String dbPath) throws IOException {
// Close the SQLiteOpenHelper so it will commit the created empty
// database to internal storage.
close();
File newDb = new File(dbPath);
File oldDb = new File(DB_FILEPATH);
if (newDb.exists()) {
FileUtils.copyFile(new FileInputStream(newDb), new FileOutputStream(oldDb));
// Access the copied database so SQLiteHelper will cache it and mark
// it as created.
getWritableDatabase().close();
return true;
}
return false;
}
FileUtils
public class FileUtils {
/**
* Creates the specified <code>toFile</code> as a byte for byte copy of the
* <code>fromFile</code>. If <code>toFile</code> already exists, then it
* will be replaced with a copy of <code>fromFile</code>. The name and path
* of <code>toFile</code> will be that of <code>toFile</code>.<br/>
* <br/>
* <i> Note: <code>fromFile</code> and <code>toFile</code> will be closed by
* this function.</i>
*
* #param fromFile
* - FileInputStream for the file to copy from.
* #param toFile
* - FileInputStream for the file to copy to.
*/
public static void copyFile(FileInputStream fromFile, FileOutputStream toFile) throws IOException {
FileChannel fromChannel = null;
FileChannel toChannel = null;
try {
fromChannel = fromFile.getChannel();
toChannel = toFile.getChannel();
fromChannel.transferTo(0, fromChannel.size(), toChannel);
} finally {
try {
if (fromChannel != null) {
fromChannel.close();
}
} finally {
if (toChannel != null) {
toChannel.close();
}
}
}
}
}
Don't forget to delete the old database file if necessary.

This is a simple method to export the database to a folder named backup folder you can name it as you want and a simple method to import the database from the same folder a
public class ExportImportDB extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
//creating a new folder for the database to be backuped to
File direct = new File(Environment.getExternalStorageDirectory() + "/Exam Creator");
if(!direct.exists())
{
if(direct.mkdir())
{
//directory is created;
}
}
exportDB();
importDB();
}
//importing database
private void importDB() {
// TODO Auto-generated method stub
try {
File sd = Environment.getExternalStorageDirectory();
File data = Environment.getDataDirectory();
if (sd.canWrite()) {
String currentDBPath= "//data//" + "PackageName"
+ "//databases//" + "DatabaseName";
String backupDBPath = "/BackupFolder/DatabaseName";
File backupDB= new File(data, currentDBPath);
File currentDB = new File(sd, backupDBPath);
FileChannel src = new FileInputStream(currentDB).getChannel();
FileChannel dst = new FileOutputStream(backupDB).getChannel();
dst.transferFrom(src, 0, src.size());
src.close();
dst.close();
Toast.makeText(getBaseContext(), backupDB.toString(),
Toast.LENGTH_LONG).show();
}
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG)
.show();
}
}
//exporting database
private void exportDB() {
// TODO Auto-generated method stub
try {
File sd = Environment.getExternalStorageDirectory();
File data = Environment.getDataDirectory();
if (sd.canWrite()) {
String currentDBPath= "//data//" + "PackageName"
+ "//databases//" + "DatabaseName";
String backupDBPath = "/BackupFolder/DatabaseName";
File currentDB = new File(data, currentDBPath);
File backupDB = new File(sd, backupDBPath);
FileChannel src = new FileInputStream(currentDB).getChannel();
FileChannel dst = new FileOutputStream(backupDB).getChannel();
dst.transferFrom(src, 0, src.size());
src.close();
dst.close();
Toast.makeText(getBaseContext(), backupDB.toString(),
Toast.LENGTH_LONG).show();
}
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG)
.show();
}
}
}
Dont forget to add this permission to proceed it
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" >
</uses-permission>
Enjoy

To export db rather it is SQLITE or ROOM:
Firstly, add this permission in AndroidManifest.xml file:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Secondly, we drive to code the db functions:
private void exportDB() {
try {
File dbFile = new File(this.getDatabasePath(DATABASE_NAME).getAbsolutePath());
FileInputStream fis = new FileInputStream(dbFile);
String outFileName = DirectoryName + File.separator +
DATABASE_NAME + ".db";
// Open the empty db as the output stream
OutputStream output = new FileOutputStream(outFileName);
// Transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = fis.read(buffer)) > 0) {
output.write(buffer, 0, length);
}
// Close the streams
output.flush();
output.close();
fis.close();
} catch (IOException e) {
Log.e("dbBackup:", e.getMessage());
}
}
Create Folder on Daily basis with name of folder is Current date:
public void createBackup() {
sharedPref = getSharedPreferences("dbBackUp", MODE_PRIVATE);
editor = sharedPref.edit();
String dt = sharedPref.getString("dt", new SimpleDateFormat("dd-MM-yy").format(new Date()));
if (dt != new SimpleDateFormat("dd-MM-yy").format(new Date())) {
editor.putString("dt", new SimpleDateFormat("dd-MM-yy").format(new Date()));
editor.commit();
}
File folder = new File(Environment.getExternalStorageDirectory() + File.separator + "BackupDBs");
boolean success = true;
if (!folder.exists()) {
success = folder.mkdirs();
}
if (success) {
DirectoryName = folder.getPath() + File.separator + sharedPref.getString("dt", "");
folder = new File(DirectoryName);
if (!folder.exists()) {
success = folder.mkdirs();
}
if (success) {
exportDB();
}
} else {
Toast.makeText(this, "Not create folder", Toast.LENGTH_SHORT).show();
}
}
Assign the DATABASE_NAME without .db extension and its data type is string

Import and Export of a SQLite database on Android
Here is my function for export database into device storage
private void exportDB(){
String DatabaseName = "Sycrypter.db";
File sd = Environment.getExternalStorageDirectory();
File data = Environment.getDataDirectory();
FileChannel source=null;
FileChannel destination=null;
String currentDBPath = "/data/"+ "com.synnlabz.sycryptr" +"/databases/"+DatabaseName ;
String backupDBPath = SAMPLE_DB_NAME;
File currentDB = new File(data, currentDBPath);
File backupDB = new File(sd, backupDBPath);
try {
source = new FileInputStream(currentDB).getChannel();
destination = new FileOutputStream(backupDB).getChannel();
destination.transferFrom(source, 0, source.size());
source.close();
destination.close();
Toast.makeText(this, "Your Database is Exported !!", Toast.LENGTH_LONG).show();
} catch(IOException e) {
e.printStackTrace();
}
}
Here is my function for import database from device storage into android application
private void importDB(){
String dir=Environment.getExternalStorageDirectory().getAbsolutePath();
File sd = new File(dir);
File data = Environment.getDataDirectory();
FileChannel source = null;
FileChannel destination = null;
String backupDBPath = "/data/com.synnlabz.sycryptr/databases/Sycrypter.db";
String currentDBPath = "Sycrypter.db";
File currentDB = new File(sd, currentDBPath);
File backupDB = new File(data, backupDBPath);
try {
source = new FileInputStream(currentDB).getChannel();
destination = new FileOutputStream(backupDB).getChannel();
destination.transferFrom(source, 0, source.size());
source.close();
destination.close();
Toast.makeText(this, "Your Database is Imported !!", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
e.printStackTrace();
}
}

If you want this in kotlin . And perfectly working
private fun exportDbFile() {
try {
//Existing DB Path
val DB_PATH = "/data/packagename/databases/mydb.db"
val DATA_DIRECTORY = Environment.getDataDirectory()
val INITIAL_DB_PATH = File(DATA_DIRECTORY, DB_PATH)
//COPY DB PATH
val EXTERNAL_DIRECTORY: File = Environment.getExternalStorageDirectory()
val COPY_DB = "/mynewfolder/mydb.db"
val COPY_DB_PATH = File(EXTERNAL_DIRECTORY, COPY_DB)
File(COPY_DB_PATH.parent!!).mkdirs()
val srcChannel = FileInputStream(INITIAL_DB_PATH).channel
val dstChannel = FileOutputStream(COPY_DB_PATH).channel
dstChannel.transferFrom(srcChannel,0,srcChannel.size())
srcChannel.close()
dstChannel.close()
} catch (excep: Exception) {
Toast.makeText(this,"ERROR IN COPY $excep",Toast.LENGTH_LONG).show()
Log.e("FILECOPYERROR>>>>",excep.toString())
excep.printStackTrace()
}
}