Develop Reference

Copy file from path to Path in Android 11

I hope you are fine.
After I have done all steps, of getting permission storage in Android 11, now I can create, copy files from assets to any folder, or delete files.
I just got a problem when try to copy file from path to path, the problem is I find the output file empty.
Only in this I need help, and I hope you help me and tell me what mistake I have in my code, and thanks in advance.
To copy I'm using:
Uri muri = Uri.parse("content://com.android.externalstorage.documents/tree/primary%3Aagora%2file.txt");
Uri uri2 = Uri.parse("content://com.android.externalstorage.documents/tree/primary%3AAlarms");
DocumentFile mfile = DocumentFile.fromTreeUri(MainActivity.this, muri);
DocumentFile mfile1 = DocumentFile.fromTreeUri(MainActivity.this, uri2);
mfile1 = mfile1.createFile("file/txt", "file.txt");
uri2 = mfile1.getUri();
if (copyFileFromUri2(MainActivity.this, muri, uri2)) {
showMessage("file copied successfully");
} else {
showMessage("failed to copy the file !");
}
The method:
public boolean copyFileFromUri2(Context context, Uri fileUri, Uri targetUri)
{
InputStream fis = null;
OutputStream fos = null;
try {
ContentResolver content = context.getContentResolver();
fis = content.openInputStream(fileUri);
fos = content.openOutputStream(targetUri);
byte[] buff = new byte[1024];
int length = 0;
while ((length = fis.read(buff)) > 0) {
fos.write(buff, 0, length);
}
} catch (IOException e) {
return false;
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
return false;
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
return false;
}
}
}
return true;
}

You can try to initialize the OutputStream os as follows:
fos = new BufferedOutputStream( content.openOutputStream(targetUri))

How can I run executable in assets?

How can I add a executable into assets and run it in Android and show the output?
I've a executable that will work. I assume there will need to be some chmod in the code.
Thank you.

here is my answer
put copyAssets() to your mainactivity.
someone's code:
private void copyAssets() {
AssetManager assetManager = getAssets();
String[] files = null;
try {
files = assetManager.list("");
} catch (IOException e) {
Log.e("tag", "Failed to get asset file list.", e);
}
for(String filename : files) {
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
File outFile = new File(getFilesDir(), filename);
out = new FileOutputStream(outFile);
copyFile(in, out);
} catch(IOException e) {
Log.e("tag", "Failed to copy asset file: " + filename, e);
}
finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
// NOOP
}
}
if (out != null) {
try {
out.close();
} catch (IOException e) {
// NOOP
}
}
}
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
}
also here is code to run command
public String runcmd(String cmd){
try {
Process p = Runtime.getRuntime().exec(cmd);
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
int read;
char[] buffer = new char[4096];
StringBuffer out = new StringBuffer();
while ((read = in.read(buffer)) > 0) {
out.append(buffer, 0, read);
}
in.close();
p.waitFor();
return out.substring(0);
} catch (IOException e) {
throw new RuntimeException(e);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
you may need to change it to
String prog= "programname";
String[] env= { "parameter 1","p2"};
File dir= new File(getFilesDir().getAbsolutePath());
Process p = Runtime.getRuntime().exec(prog,env,dir);
to ensure proper parameter handling
also add this to your main code
to check proper copying of files
String s;
File file4 = new File(getFilesDir().getAbsolutePath()+"/executable");
file4.setExecutable(true);
s+=file4.getName();
s+=file4.exists();
s+=file4.canExecute();
s+=file4.length();
//output s however you want it
should write: filename, true, true, correct filelength.

Place your executable in raw folder, then run it by using ProcessBuilder or Runtime.exec like they do here http://gimite.net/en/index.php?Run%20native%20executable%20in%20Android%20App

Android - Copy assets to internal storage

Good day!
I have just started developing for android. In my app, I need to copy the items in my assets folder to the internal storage.
I have searched a lot on SO including this which copies it to the external storage.
How to copy files from 'assets' folder to sdcard?
This is what I want to achieve:
I have a directory already present in the internal storage as X>Y>Z. I need a file to be copied to Y and another to Z.
Can anyone help me out with a code snippet? I really don't have any idea how to go on about this.
Sorry for my bad English.
Thanks a lot.

Use
String out= Environment.getExternalStorageDirectory().getAbsolutePath() + "/X/Y/Z/" ;
File outFile = new File(out, Filename);
After Editing in your ref. Link Answer.
private void copyAssets() {
AssetManager assetManager = getAssets();
String[] files = null;
try {
files = assetManager.list("");
} catch (IOException e) {
Log.e("tag", "Failed to get asset file list.", e);
}
for(String filename : files) {
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
String outDir = Environment.getExternalStorageDirectory().getAbsolutePath() + "/X/Y/Z/" ;
File outFile = new File(outDir, filename);
out = new FileOutputStream(outFile);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch(IOException e) {
Log.e("tag", "Failed to copy asset file: " + filename, e);
}
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}

I did something like this. This allows you to copy all the directory structure to copy from Android AssetManager.
public String copyDirorfileFromAssetManager(String arg_assetDir, String arg_destinationDir) throws IOException
{
File sd_path = Environment.getExternalStorageDirectory();
String dest_dir_path = sd_path + addLeadingSlash(arg_destinationDir);
File dest_dir = new File(dest_dir_path);
createDir(dest_dir);
AssetManager asset_manager = getApplicationContext().getAssets();
String[] files = asset_manager.list(arg_assetDir);
for (int i = 0; i < files.length; i++)
{
String abs_asset_file_path = addTrailingSlash(arg_assetDir) + files[i];
String sub_files[] = asset_manager.list(abs_asset_file_path);
if (sub_files.length == 0)
{
// It is a file
String dest_file_path = addTrailingSlash(dest_dir_path) + files[i];
copyAssetFile(abs_asset_file_path, dest_file_path);
} else
{
// It is a sub directory
copyDirorfileFromAssetManager(abs_asset_file_path, addTrailingSlash(arg_destinationDir) + files[i]);
}
}
return dest_dir_path;
}
public void copyAssetFile(String assetFilePath, String destinationFilePath) throws IOException
{
InputStream in = getApplicationContext().getAssets().open(assetFilePath);
OutputStream out = new FileOutputStream(destinationFilePath);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0)
out.write(buf, 0, len);
in.close();
out.close();
}
public String addTrailingSlash(String path)
{
if (path.charAt(path.length() - 1) != '/')
{
path += "/";
}
return path;
}
public String addLeadingSlash(String path)
{
if (path.charAt(0) != '/')
{
path = "/" + path;
}
return path;
}
public void createDir(File dir) throws IOException
{
if (dir.exists())
{
if (!dir.isDirectory())
{
throw new IOException("Can't create directory, a file is in the way");
}
} else
{
dir.mkdirs();
if (!dir.isDirectory())
{
throw new IOException("Unable to create directory");
}
}
}

try this below code
private void copyAssets() {
AssetManager assetManager = getAssets();
String[] files = null;
try {
files = assetManager.list("");
} catch (IOException e) {
Log.e("tag", "Failed to get asset file list.", e);
}
for(String filename : files) {
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
File outFile = new File(getExternalFilesDir(null), filename);
out = new FileOutputStream(outFile);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch(IOException e) {
Log.e("tag", "Failed to copy asset file: " + filename, e);
}
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}

This is my Kotlin solution with auto-closable streams to copy in internal app storage:
val copiedFile = File(context.filesDir, "copied_file.txt")
context.assets.open("original_file.txt").use { input ->
copiedFile.outputStream().use { output ->
input.copyTo(output, 1024)
}
}

My small solution on Kotlin, for copy data from assets to INTERNAL STORAGE
fun copy() {
val bufferSize = 1024
val assetManager = context.assets
val assetFiles = assetManager.list("")
assetFiles.forEach {
val inputStream = assetManager.open(it)
val outputStream = FileOutputStream(File(context.filesDir, it))
try {
inputStream.copyTo(outputStream, bufferSize)
} finally {
inputStream.close()
outputStream.flush()
outputStream.close()
}
}
}

public void addFilesToSystem(String sysName, String intFil, Context c){
//sysName is the name of the file we have in the android os
//intFil is the name of the internal file
file = new File(path, sysName + ".txt");
if(!file.exists()){
path.mkdirs();
try {
AssetManager am = c.getAssets();
InputStream is = am.open(intFil);
OutputStream os = new FileOutputStream(file);
byte[] data = new byte[is.available()];
is.read(data);
os.write(data);
is.close();
os.close();
Toast t = Toast.makeText(c, "Making file: " + file.getName() + ". One time action", Toast.LENGTH_LONG);
t.show();
//Update files for the user to use
MediaScannerConnection.scanFile(c,
new String[] {file.toString()},
null,
new MediaScannerConnection.OnScanCompletedListener() {
public void onScanCompleted(String path, Uri uri) {
// TODO Auto-generated method stub
}
});
} catch (IOException e) {
Toast t = Toast.makeText(c, "Error: " + e.toString() + ". One time action", Toast.LENGTH_LONG);
t.show();
e.printStackTrace();
}
}
}
To add a file, call the addFilesToSystem("this_file_is_in_the_public_system", "this_file_is_in_the_assets_folder", context/this context is if you do not have the method in the Activity/
Hope it helps

You can use the Envrionment#getDataDirectory method for that. It'll give the path of the data directory of the internal storage memory. This is generally where all the app related data is stored.
Alternately, if you want to store in the root directory, you can use the Environment#getRootDirectory method for that.

If you need to copy any file from assets to the internal storage and do it only once:
public void writeFileToStorage() {
Logger.d(TAG, ">> writeFileToStorage");
AssetManager assetManager = mContext.getAssets();
if (new File(getFilePath()).exists()) {
Logger.d(TAG, "File exists, do nothing");
Logger.d(TAG, "<< writeFileToStorage");
return;
}
try (InputStream input = assetManager.open(FILE_NAME);
OutputStream output = new FileOutputStream(getFilePath())) {
Logger.d(TAG, "File does not exist, write it");
byte[] buffer = new byte[input.available()];
int length;
while ((length = input.read(buffer)) != -1) {
output.write(buffer, 0, length);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
Logger.e(TAG, "File is not found");
} catch (IOException e) {
e.printStackTrace();
Logger.d(TAG, "Error while writing the file");
}
Logger.d(TAG, "<< writeFileToStorage");
}
public String getFilePath() {
String filePath = mContext.getFilesDir() + "/" + FILE_NAME;
Logger.d(TAG, "File path: " + filePath);
return filePath;
}

File.delete() won't delete the file

There's something going on here that I don't understand. This code deletes all the files in the "stuff"directory:
public static void main(String[] args) throws Exception {
File dire = new File("C:\\Users\\spacitron\\Desktop\\Stuff");
for (File doc : dire.listFiles()) {
doc.delete();
}
}
However it won't work if I try to do something useful with it, such as only deleting duplicate files:
public static void main(String[] args) throws Exception {
File dire = new File("C:\\Users\\spacitron\\Desktop\\Stuff");
ArrayList<String> hashes = new ArrayList<>();
for (File doc : dire.listFiles()) {
String docHash = getHash(doc);
if (hashes.contains(docHash)) {
doc.delete();
} else {
hashes.add(docHash);
}
}
}
public static String getHash(File d) {
MessageDigest md = null;
try {
md = MessageDigest.getInstance("SHA1");
FileInputStream inStream = new FileInputStream(d);
DigestInputStream dis = new DigestInputStream(inStream, md);
BufferedInputStream bis = new BufferedInputStream(dis);
while (true) {
int b = bis.read();
if (b == -1)
break;
}
} catch (NoSuchAlgorithmException | IOException e) {
e.printStackTrace();
}
BigInteger bi = new BigInteger(md.digest());
return bi.toString(16);
}
What gives?

You need to close your input streams in a finally block would be best, These will be accessing you files still preventing them from being deleted as they are in use
FileInputStream inStream = null;
DigestInputStream dis = null;
BufferedInputStream bis = null;
try {
md = MessageDigest.getInstance("SHA1");
inStream = new FileInputStream(d);
dis = new DigestInputStream(inStream, md);
bis = new BufferedInputStream(dis);
while (true) {
int b = bis.read();
if (b == -1)
break;
}
} catch (NoSuchAlgorithmException | IOException e) {
e.printStackTrace();
} finally {
try{
if(inStream!= null)
inStream.close();
if(dis != null)
dis.close();
if(bis != null)
bis.close()
} catch (Exception ex){
ex.printStackTrace()
}
}

Windows does not permit deleting files that are open, unless they are opened with a special flag that is unavailable when programming in Java. While this code would work on a Unix system, on Windows it won't.
Closing open files is a good idea in general because operating systems impose a limit on the number of files that an application can have open at any given time.

How to download a text file via FTP and read the contents to a string

This is re-worded from a previous question (which was probably a bit unclear).
I want to download a text file via FTP from a remote server, read the contents of the text file into a string and then discard the file. I don't need to actually save the file.
I am using the Apache Commons library so I have:
import org.apache.commons.net.ftp.FTPClient;
Can anyone help please, without simply redirecting me to a page with lots of possible answers on?

Not going to do the work for you, but once you have your connection established, you can call retrieveFile and pass it an OutputStream. You can google around and find the rest...
FTPClient ftp = new FTPClient();
...
ByteArrayOutputStream myVar = new ByteArrayOutputStream();
ftp.retrieveFile("remoteFileName.txt", myVar);
ByteArrayOutputStream
retrieveFile

Normally I'd leave a comment asking 'What have you tried?'. But now I'm feeling more generous :-)
Here you go:
private void ftpDownload() {
FTPClient ftp = null;
try {
ftp = new FTPClient();
ftp.connect(mServer);
try {
int reply = ftp.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
throw new Exception("Connect failed: " + ftp.getReplyString());
}
if (!ftp.login(mUser, mPassword)) {
throw new Exception("Login failed: " + ftp.getReplyString());
}
try {
ftp.enterLocalPassiveMode();
if (!ftp.setFileType(FTP.BINARY_FILE_TYPE)) {
Log.e(TAG, "Setting binary file type failed.");
}
transferFile(ftp);
} catch(Exception e) {
handleThrowable(e);
} finally {
if (!ftp.logout()) {
Log.e(TAG, "Logout failed.");
}
}
} catch(Exception e) {
handleThrowable(e);
} finally {
ftp.disconnect();
}
} catch(Exception e) {
handleThrowable(e);
}
}
private void transferFile(FTPClient ftp) throws Exception {
long fileSize = getFileSize(ftp, mFilePath);
InputStream is = retrieveFileStream(ftp, mFilePath);
downloadFile(is, buffer, fileSize);
is.close();
if (!ftp.completePendingCommand()) {
throw new Exception("Pending command failed: " + ftp.getReplyString());
}
}
private InputStream retrieveFileStream(FTPClient ftp, String filePath)
throws Exception {
InputStream is = ftp.retrieveFileStream(filePath);
int reply = ftp.getReplyCode();
if (is == null
|| (!FTPReply.isPositivePreliminary(reply)
&& !FTPReply.isPositiveCompletion(reply))) {
throw new Exception(ftp.getReplyString());
}
return is;
}
private byte[] downloadFile(InputStream is, long fileSize)
throws Exception {
byte[] buffer = new byte[fileSize];
if (is.read(buffer, 0, buffer.length)) == -1) {
return null;
}
return buffer; // <-- Here is your file's contents !!!
}
private long getFileSize(FTPClient ftp, String filePath) throws Exception {
long fileSize = 0;
FTPFile[] files = ftp.listFiles(filePath);
if (files.length == 1 && files[0].isFile()) {
fileSize = files[0].getSize();
}
Log.i(TAG, "File size = " + fileSize);
return fileSize;
}

You can just skip the download to local filesystem part and do:
FTPClient ftpClient = new FTPClient();
try {
ftpClient.connect(server, port);
ftpClient.login(user, pass);
ftpClient.enterLocalPassiveMode();
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
InputStream inputStream = ftpClient.retrieveFileStream("/folder/file.dat");
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "Cp1252"));
while(reader.ready()) {
System.out.println(reader.readLine()); // Or whatever
}
inputStream.close();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
if (ftpClient.isConnected()) {
ftpClient.logout();
ftpClient.disconnect();
}
} catch (IOException ex) {
ex.printStackTrace();
}
}