I am now building an file sharing app in android and i have tried to get all the files on a certain directory (in my case it is the mp3 directory). while I was doing it using the function File.listFiles() it was returning null for no reason that I know of.
directorys = new File(Environment.getExternalStorageDirectory().toString()+"/mp3");
Log.d(TAG,directorys.listFiles().length+"");
after it an exception has be given for that listFiles is an null array?
btw I have used this permission
<uses-permission- android:name="android.permission.READ_EXTERNAL_STORAGE"/>
try this code
String path = Environment.getExternalStorageDirectory().toString()+"/mp3";
Log.d("Files", "Path: " + path);
File directory = new File(path);
File[] files = directory.listFiles();
Log.d("Files", "Size: "+ files.length);
for (int i = 0; i < files.length; i++)
{
Log.d("Files", "FileName:" + files[i].getName());
}
and from marshmallow and above version you need to add permission programaticaly
public boolean requestForPermission() {
boolean isPermissionOn = true;
final int version = Build.VERSION.SDK_INT;
if (version >= 23) {
if (!canAccessExternalSd()) {
isPermissionOn = false;
requestPermissions(EXTERNAL_PERMS, EXTERNAL_REQUEST);
}
}
return isPermissionOn; }
public boolean canAccessExternalSd() {
return (hasPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)); }
private boolean hasPermission(String perm) {
return (PackageManager.PERMISSION_GRANTED == ContextCompat.checkSelfPermission(this, perm));
}
Hi friend thanks for previous replies,
i am facing problem in removing cache and temp files/folders,
what i require is to clean the whole device temp files and cache from one app which is mine app
but here i am able to clean only my apps cache , here is my code
private void mAppMethod(List<App> mApps) {
// TODO Auto-generated method stub
// File f = g
for (int i = 0; i < mApps.size(); i++) {
File dir = new File("/data/data/"+mApps.get(i).getPackageName().concat("/cache"));
Log.e("dir "+dir, "is directory "+dir.isDirectory());
int j = clearCacheFolder(dir, 10);
if (dir!= null && dir.isDirectory())
Log.e("j", "rff "+dir.delete());
System.out.println(j+" rff "+dir.delete());
}
and my clear cache method as under
static int clearCacheFolder(final File dir, final int numDays) {
int deletedFiles = 0;
if (dir!= null && dir.isDirectory()) {
// System.out.println("here"+dir.delete());
Log.e("here", "here "+dir.isDirectory());
try {
Log.e("here1", "here1"+dir.listFiles());
for (File child:dir.listFiles()) {
Log.e("here11", "here11");
//first delete subdirectories recursively
if (child.isDirectory()) {
Log.e("here111", "here111");
deletedFiles += clearCacheFolder(child, numDays);
Log.e("here1111", "here1111");
}
Log.e("here11111", "here11111");
//then delete the files and subdirectories in this dir
//only empty directories can be deleted, so subdirs have been done first
if (child.lastModified() < new Date().getTime() - numDays * DateUtils.DAY_IN_MILLIS) {
Log.e("here111111", "here111111");
if (child.delete()) {
Log.e("here1111111", "here1111111");
deletedFiles++;
Log.e("here11111111", "here11111111");
}
}
}
}
catch(Exception e) {
Log.e("TAG", String.format("Failed to clean the cache, error %s", e.getMessage()));
}
}
return deletedFiles;
}
please help how can i clear the whole device cache,here i am getting every apps cache location i.e. dir to cache of all apps in device but when i want to delete them it returns false
please help any help is appreciable
i am able to clear cache of one app which is the one i am running this code but not for other apps
thanks in advance
Try with this code
public void clearApplicationData() {
File cache = getCacheDir();
File appDir = new File(cache.getParent());
if(appDir.exists()){
String[] children = appDir.list();
for(String s : children){
if(!s.equals("lib")){
deleteDir(new File(appDir, s));
Log.i("TAG", "**************** File /data/data/APP_PACKAGE/" + s +" DELETED *******************");
}
}
}
}
public static boolean deleteDir(File dir) {
if (dir != null && dir.isDirectory()) {
String[] children = dir.list();
for (int i = 0; i < children.length; i++) {
boolean success = deleteDir(new File(dir, children[i]));
if (!success) {
return false;
}
}
}
return dir.delete();
}
This will delete your all data,and cache files in the application.
I want the users of my application to be able to delete the DCIM folder (which is located on the SD card and contains subfolders).
Is this possible, if so how?
You can delete files and folders recursively like this:
void deleteRecursive(File fileOrDirectory) {
if (fileOrDirectory.isDirectory())
for (File child : fileOrDirectory.listFiles())
deleteRecursive(child);
fileOrDirectory.delete();
}
Let me tell you first thing you cannot delete the DCIM folder because it is a system folder. As you delete it manually on phone it will delete the contents of that folder, but not the DCIM folder. You can delete its contents by using the method below:
Updated as per comments
File dir = new File(Environment.getExternalStorageDirectory()+"Dir_name_here");
if (dir.isDirectory())
{
String[] children = dir.list();
for (int i = 0; i < children.length; i++)
{
new File(dir, children[i]).delete();
}
}
We can use the command line arguments to delete a whole folder and its contents.
public static void deleteFiles(String path) {
File file = new File(path);
if (file.exists()) {
String deleteCmd = "rm -r " + path;
Runtime runtime = Runtime.getRuntime();
try {
runtime.exec(deleteCmd);
} catch (IOException e) { }
}
}
Example usage of the above code:
deleteFiles("/sdcard/uploads/");
In Kotlin you can use deleteRecursively() extension from kotlin.io package
val someDir = File("/path/to/dir")
someDir.deleteRecursively()
Short koltin version
fun File.deleteDirectory(): Boolean {
return if (exists()) {
listFiles()?.forEach {
if (it.isDirectory) {
it.deleteDirectory()
} else {
it.delete()
}
}
delete()
} else false
}
UPDATE
Kotlin stdlib function
file.deleteRecursively()
use below method to delete entire main directory which contains files and it's sub directory. After calling this method once again call delete() directory of your main directory.
// For to Delete the directory inside list of files and inner Directory
public static boolean deleteDir(File dir) {
if (dir.isDirectory()) {
String[] children = dir.list();
for (int i=0; i<children.length; i++) {
boolean success = deleteDir(new File(dir, children[i]));
if (!success) {
return false;
}
}
}
// The directory is now empty so delete it
return dir.delete();
}
Your approach is decent for a folder that only contains files, but if you are looking for a scenario that also contains subfolders then recursion is needed
Also you should capture the return value of the return to make sure you are allowed to delete the file
and include
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
in your manifest
void DeleteRecursive(File dir)
{
Log.d("DeleteRecursive", "DELETEPREVIOUS TOP" + dir.getPath());
if (dir.isDirectory())
{
String[] children = dir.list();
for (int i = 0; i < children.length; i++)
{
File temp = new File(dir, children[i]);
if (temp.isDirectory())
{
Log.d("DeleteRecursive", "Recursive Call" + temp.getPath());
DeleteRecursive(temp);
}
else
{
Log.d("DeleteRecursive", "Delete File" + temp.getPath());
boolean b = temp.delete();
if (b == false)
{
Log.d("DeleteRecursive", "DELETE FAIL");
}
}
}
}
dir.delete();
}
There is a lot of answers, but I decided to add my own, because it's little different. It's based on OOP ;)
I created class DirectoryCleaner, which help me each time when I need to clean some directory.
public class DirectoryCleaner {
private final File mFile;
public DirectoryCleaner(File file) {
mFile = file;
}
public void clean() {
if (null == mFile || !mFile.exists() || !mFile.isDirectory()) return;
for (File file : mFile.listFiles()) {
delete(file);
}
}
private void delete(File file) {
if (file.isDirectory()) {
for (File child : file.listFiles()) {
delete(child);
}
}
file.delete();
}
}
It can be used to solve this problem in next way:
File dir = new File(Environment.getExternalStorageDirectory(), "your_directory_name");
new DirectoryCleaner(dir).clean();
dir.delete();
You can not delete the directory if it has subdirectories or files in Java. Try this two-line simple solution. This will delete the directory and contests inside the directory.
File dirName = new File("directory path");
FileUtils.deleteDirectory(dirName);
Add this line in gradle file and sync the project
compile 'org.apache.commons:commons-io:1.3.2'
According to the documentation:
If this abstract pathname does not denote a directory, then this method returns null.
So you should check if listFiles is null and only continue if it's not
boolean deleteDirectory(File path) {
if(path.exists()) {
File[] files = path.listFiles();
if (files == null) {
return false;
}
for (File file : files) {
if (file.isDirectory()) {
deleteDirectory(file);
} else {
boolean wasSuccessful = file.delete();
if (wasSuccessful) {
Log.i("Deleted ", "successfully");
}
}
}
}
return(path.delete());
}
If you dont need to delete things recursively you can try something like this:
File file = new File(context.getExternalFilesDir(null), "");
if (file != null && file.isDirectory()) {
File[] files = file.listFiles();
if(files != null) {
for(File f : files) {
f.delete();
}
}
}
public static void deleteDirectory( File dir )
{
if ( dir.isDirectory() )
{
String [] children = dir.list();
for ( int i = 0 ; i < children.length ; i ++ )
{
File child = new File( dir , children[i] );
if(child.isDirectory()){
deleteDirectory( child );
child.delete();
}else{
child.delete();
}
}
dir.delete();
}
}
see android.os.FileUtils, it's hide on API 21
public static boolean deleteContents(File dir) {
File[] files = dir.listFiles();
boolean success = true;
if (files != null) {
for (File file : files) {
if (file.isDirectory()) {
success &= deleteContents(file);
}
if (!file.delete()) {
Log.w("Failed to delete " + file);
success = false;
}
}
}
return success;
}
Source: https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/os/FileUtils.java#414
The fastest and easiest way:
public static boolean deleteFolder(File removableFolder) {
File[] files = removableFolder.listFiles();
if (files != null && files.length > 0) {
for (File file : files) {
boolean success;
if (file.isDirectory())
success = deleteFolder(file);
else success = file.delete();
if (!success) return false;
}
}
return removableFolder.delete();
}
This is what I do... (terse and tested)
...
deleteDir(new File(dir_to_be_deleted));
...
// delete directory and contents
void deleteDir(File file) {
if (file.isDirectory())
for (String child : file.list())
deleteDir(new File(file, child));
file.delete(); // delete child file or empty directory
}
private static void deleteRecursive(File dir)
{
//Log.d("DeleteRecursive", "DELETEPREVIOUS TOP" + dir.getPath());
if (dir.isDirectory())
{
String[] children = dir.list();
for (int i = 0; i < children.length; i++)
{
File temp = new File(dir, children[i]);
deleteRecursive(temp);
}
}
if (dir.delete() == false)
{
Log.d("DeleteRecursive", "DELETE FAIL");
}
}
Simple way to delete all file from directory :
It is generic function for delete all images from directory by calling only
deleteAllImageFile(context);
public static void deleteAllFile(Context context) {
File directory = context.getExternalFilesDir(null);
if (directory.isDirectory()) {
for (String fileName: file.list()) {
new File(file,fileName).delete();
}
}
}
Safest code I know:
private boolean recursiveRemove(File file) {
if(file == null || !file.exists()) {
return false;
}
if(file.isDirectory()) {
File[] list = file.listFiles();
if(list != null) {
for(File item : list) {
recursiveRemove(item);
}
}
}
if(file.exists()) {
file.delete();
}
return !file.exists();
}
Checks the file exists, handles nulls, checks the directory was actually deleted
//To delete all the files of a specific folder & subfolder
public static void deleteFiles(File directory, Context c) {
try {
for (File file : directory.listFiles()) {
if (file.isFile()) {
final ContentResolver contentResolver = c.getContentResolver();
String canonicalPath;
try {
canonicalPath = file.getCanonicalPath();
} catch (IOException e) {
canonicalPath = file.getAbsolutePath();
}
final Uri uri = MediaStore.Files.getContentUri("external");
final int result = contentResolver.delete(uri,
MediaStore.Files.FileColumns.DATA + "=?", new String[]{canonicalPath});
if (result == 0) {
final String absolutePath = file.getAbsolutePath();
if (!absolutePath.equals(canonicalPath)) {
contentResolver.delete(uri,
MediaStore.Files.FileColumns.DATA + "=?", new String[]{absolutePath});
}
}
if (file.exists()) {
file.delete();
if (file.exists()) {
try {
file.getCanonicalFile().delete();
} catch (IOException e) {
e.printStackTrace();
}
if (file.exists()) {
c.deleteFile(file.getName());
}
}
}
} else
deleteFiles(file, c);
}
} catch (Exception e) {
}
}
here is your solution it will also refresh the gallery as well.
This (Tries to delete all sub-files and sub-directories including the supplied directory):
If File, delete
If Empty Directory, delete
if Not Empty Directory, call delete again with sub-directory, repeat 1 to 3
example:
File externalDir = Environment.getExternalStorageDirectory()
Utils.deleteAll(externalDir); //BE CAREFUL.. Will try and delete ALL external storage files and directories
To gain access to External Storage Directory, you need the following permissions:
(Use ContextCompat.checkSelfPermission and ActivityCompat.requestPermissions)
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Recursive method:
public static boolean deleteAll(File file) {
if (file == null || !file.exists()) return false;
boolean success = true;
if (file.isDirectory()) {
File[] files = file.listFiles();
if (files != null && files.length > 0) {
for (File f : files) {
if (f.isDirectory()) {
success &= deleteAll(f);
}
if (!f.delete()) {
Log.w("deleteAll", "Failed to delete " + f);
success = false;
}
}
} else {
if (!file.delete()) {
Log.w("deleteAll", "Failed to delete " + file);
success = false;
}
}
} else {
if (!file.delete()) {
Log.w("deleteAll", "Failed to delete " + file);
success = false;
}
}
return success;
}
Here is a non-recursive implementation, just for fun:
/**
* Deletes the given folder and all its files / subfolders.
* Is not implemented in a recursive way. The "Recursively" in the name stems from the filesystem command
* #param root The folder to delete recursively
*/
public static void deleteRecursively(final File root) {
LinkedList<File> deletionQueue = new LinkedList<>();
deletionQueue.add(root);
while(!deletionQueue.isEmpty()) {
final File toDelete = deletionQueue.removeFirst();
final File[] children = toDelete.listFiles();
if(children == null || children.length == 0) {
// This is either a file or an empty directory -> deletion possible
toDelete.delete();
} else {
// Add the children before the folder because they have to be deleted first
deletionQueue.addAll(Arrays.asList(children));
// Add the folder again because we can't delete it yet.
deletionQueue.addLast(toDelete);
}
}
}
I've put this one though its' paces it deletes a folder with any directory structure.
public int removeDirectory(final File folder) {
if(folder.isDirectory() == true) {
File[] folderContents = folder.listFiles();
int deletedFiles = 0;
if(folderContents.length == 0) {
if(folder.delete()) {
deletedFiles++;
return deletedFiles;
}
}
else if(folderContents.length > 0) {
do {
File lastFolder = folder;
File[] lastFolderContents = lastFolder.listFiles();
//This while loop finds the deepest path that does not contain any other folders
do {
for(File file : lastFolderContents) {
if(file.isDirectory()) {
lastFolder = file;
lastFolderContents = file.listFiles();
break;
}
else {
if(file.delete()) {
deletedFiles++;
}
else {
break;
}
}//End if(file.isDirectory())
}//End for(File file : folderContents)
} while(lastFolder.delete() == false);
deletedFiles++;
if(folder.exists() == false) {return deletedFiles;}
} while(folder.exists());
}
}
else {
return -1;
}
return 0;
}
Hope this helps.
Yet another (modern) way to solve it.
public class FileUtils {
public static void delete(File fileOrDirectory) {
if(fileOrDirectory != null && fileOrDirectory.exists()) {
if(fileOrDirectory.isDirectory() && fileOrDirectory.listFiles() != null) {
Arrays.stream(fileOrDirectory.listFiles())
.forEach(FileUtils::delete);
}
fileOrDirectory.delete();
}
}
}
On Android since API 26
public class FileUtils {
public static void delete(File fileOrDirectory) {
if(fileOrDirectory != null) {
delete(fileOrDirectory.toPath());
}
}
public static void delete(Path path) {
try {
if(Files.exists(path)) {
Files.walk(path)
.sorted(Comparator.reverseOrder())
.map(Path::toFile)
// .peek(System.out::println)
.forEach(File::delete);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
I'm using this recursive function to do the job:
public static void deleteDirAndContents(#NonNull File mFile){
if (mFile.isDirectory() && mFile.listFiles() != null && mFile.listFiles().length > 0x0) {
for (File file : mFile.listFiles()) {
deleteDirAndContents(file);
}
} else {
mFile.delete();
}
}
The function checks if it is a directory or a file.
If it is a directory checks if it has child files, if it has child files will call herself again passing the children and repeating.
If it is a file it delete it.
(Don't use this function to clear the app cache by passing the cache dir because it will delete the cache dir too so the app will crash...
If you want to clear the cache you use this function that won't delete the dir you pass to it:
public static void deleteDirContents(#NonNull File mFile){
if (mFile.isDirectory() && mFile.listFiles() != null && mFile.listFiles().length > 0x0) {
for (File file : mFile.listFiles()) {
deleteDirAndContents(file);
}
}
}
or you can check if it is the cache dir using:
if (!mFile.getAbsolutePath().equals(context.getCacheDir().getAbsolutePath())) {
mFile.delete();
}
Example code to clear app cache:
public static void clearAppCache(Context context){
try {
File cache = context.getCacheDir();
FilesUtils.deleteDirContents(cache);
} catch (Exception e){
MyLogger.onException(TAG, e);
}
}
Bye, Have a nice day & coding :D
This is kotlin option. It worked very well.
fun executeDelete(context: Context, paths: List<String>): Int {
return try {
val files = paths.map { File(it) }
val fileCommands = files.joinToString(separator = " ") {
if (it.isDirectory) "'${it.absolutePath}/'" else "'${it.absolutePath}'"
}
val command = "rm -rf $fileCommands"
val process = Runtime.getRuntime().exec(arrayOf("sh", "-c", command))
val result = process.waitFor()
if (result == 0) {
context.rescanPaths(paths)
}
result
} catch (e: Exception) {
-1
}
}
// avoid calling this multiple times in row, it can delete whole folder contents
fun Context.rescanPaths(paths: List<String>, callback: (() -> Unit)? = null) {
if (paths.isEmpty()) {
callback?.invoke()
return
}
var cnt = paths.size
MediaScannerConnection.scanFile(applicationContext, paths.toTypedArray(), null) { _, _ ->
if (--cnt == 0) {
callback?.invoke()
}
}
}