Trying to check if a file exists in internal storage - java

The following code is how I am trying to identify if a file exists in the internal storage, MODE_PRIVATE.
public boolean isset(String filename){
FileInputStream fos = null;
try {
fos = openFileInput(filename);
//fos = openFileInput(getFilesDir()+"/"+filename);
if (fos != null) {
return true;
}else{
return false;
}
} catch (FileNotFoundException e) {
return false;
}
//File file=new File(mContext.getFilesDir(),filename);
//boolean exists = fos.exists();
}
However, it goes into the exception and doesn't continue with the code. It doesn't do the return. Why?

hope this method helps you.
public boolean fileExist(String fname){
File file = getBaseContext().getFileStreamPath(fname);
return file.exists();
}

For internal storage, this works for me:
public boolean isFilePresent(String fileName) {
String path = getContext().getFilesDir().getAbsolutePath() + "/" + fileName;
File file = new File(path);
return file.exists();
}

Kotlin: This works for me !!
fun check(path: String?): Boolean
{
val file = File(path)
return file.exists()
}

Related

What are some possible reasons for "Zip Path Traversal Vulnerability" happens only in Android 11?

Based on https://support.google.com/faqs/answer/9294009, we implement "Zip Path Traversal Vulnerability" detection in our code.
We are getting crash log from Google Play Console, as we run throw new SecurityException("https://support.google.com/faqs/answer/9294009"); explicitly when we encounter "Zip Path Traversal Vulnerability".
Currently, sometimes, I have "Zip Path Traversal Vulnerability" happens only in Android 11.
public static boolean extractZipFile(InputStream inputStream, String destDirectory, boolean overwrite) {
ZipInputStream zipInputStream = null;
boolean status = true;
try {
zipInputStream = new ZipInputStream(inputStream);
final byte[] data = new byte[1024];
while (true) {
ZipEntry zipEntry = null;
FileOutputStream outputStream = null;
try {
zipEntry = zipInputStream.getNextEntry();
if (zipEntry == null) {
break;
}
final File destination = new File(destDirectory, zipEntry.getName());
final String canonicalPath = destination.getCanonicalPath();
if (!canonicalPath.startsWith(destDirectory)) {
throw new SecurityException("https://support.google.com/faqs/answer/9294009");
}
I always ensure destDirectory is non null, before calling extractZipFile
public static boolean extractZipFile(InputStream inputStream, boolean overwrite) {
String destDirectory = Utils.getUserDataDirectory();
if (destDirectory == null) {
return false;
}
return extractZipFile(inputStream, destDirectory, overwrite);
}
public static String getUserDataDirectory() {
if (externalFilesDir == null) {
File _externalFilesDir = JStockApplication.instance().getExternalFilesDir(null);
externalFilesDir = _externalFilesDir;
if (externalFilesDir == null) {
return null;
}
}
return toEndWithFileSeperator(externalFilesDir.toString()) + getApplicationVersionString() + File.separator;
}
private static String toEndWithFileSeperator(String string) {
if (string.endsWith(File.separator)) {
return string;
}
return string + File.separator;
}
public static String getApplicationVersionString() {
return "1.0.7";
}
Based on the posed source code, do you have any guess reason, why "Zip Path Traversal Vulnerability" happens only in Android 11? I use emulator Android 11 but not able to reproduce the problem.
Where does the zip file come from?
The zip file comes from 2 places
Bundled with APK as shown in below screenshot
We use the following code to extract it during runtime.
private void initPreloadDatabase(boolean overWrite) {
AssetManager assetManager = getResources().getAssets();
InputStream inputStream = null;
try {
inputStream = assetManager.open("database" + File.separator + "database.zip");
} catch (IOException e) {
Log.e(TAG, "", e);
}
if (inputStream != null) {
org.yccheok.jstock.gui.Utils.extractZipFile(inputStream, overWrite);
}
}
Another zip file is downloaded from
https://raw.githubusercontent.com/yccheok/jstock/master/appengine/jstock-android-static/war/stocks_information/unitedstate/stocks.zip
In Utils.getUserDataDirectory() function use:
getFilesDir().getCanonicalFile()
instead of
getExternalFilesDir()

How to restore file from GDrive?

I am making an app which stores its SQLite Database backup on GDrive. I succeeded in signing in and uploading the file in the drive but failed to restore it. Following is the code.
I use SQLiteDatabase to store the fileID so that when it is required while updating and restoring, it can be used. I am looking for a method which will make use of FileID to restore.
Error occurs at file.getDownloadUrl() and file.getContent().
class DriveClassHelper
{
private final Executor mExecutor = Executors.newSingleThreadExecutor();
private static Drive mDriveService;
private String FileID = null;
private static String filePath = "/data/data/com.example.gdrivebackup/databases/Data.db";
DriveClassHelper(Drive mDriveService)
{
DriveClassHelper.mDriveService = mDriveService;
}
// ---------------------------------- TO BackUp on Drive -------------------------------------------
public Task<String> createFile()
{
return Tasks.call(mExecutor, () ->
{
File fileMetaData = new File();
fileMetaData.setName("Backup");
java.io.File file = new java.io.File(filePath);
String mimeType = MimeTypeMap.getSingleton().getExtensionFromMimeType("application/x-sqlite-3");
FileContent mediaContent = new FileContent(mimeType, file);
File myFile = null;
FileID = getFileIDFromDatabase();
try {
if (FileID != null) {
Log.i("CALLED : ", FileID);
//mDriveService.files().delete().execute();
myFile = mDriveService.files().update(FileID, fileMetaData, mediaContent).execute();
} else {
myFile = mDriveService.files().create(fileMetaData, mediaContent).execute();
MainActivity.demoSQLite.insertData(myFile.getId());
}
} catch (Exception e) {
e.printStackTrace();
}
if (myFile == null) {
throw new IOException("Null Result when requesting file creation");
}
Log.i("ID:", myFile.getId());
return myFile.getId();
}
);
}
// -------------------------------------------------------------------------------------------------
// ---------------------------------- TO get File ID -------------------------------------------
private static String getFileIDFromDatabase()
{
String FileIDFromMethod = null;
Cursor result = MainActivity.demoSQLite.getData();
if (result.getCount() == 0) {
Log.i("CURSOR :", "NO ENTRY");
return null;
} else {
while (result.moveToNext()) {
FileIDFromMethod = result.getString(0);
}
return FileIDFromMethod;
}
}
// -------------------------------------------------------------------------------------------------
// ---------------------------------- TO Restore -------------------------------------------
public static class Restore extends AsyncTask<Void, Void, String>
{
#Override
protected String doInBackground(Void... params) {
String fileId = null;
try
{
fileId = getFileIDFromDatabase();
if (fileId != null)
{
File file = mDriveService.files().get(fileId).execute();
downloadFile(file);
}
else
{
return null;
}
}
catch (Exception e)
{
e.printStackTrace();
}
return fileId;
}
private void downloadFile(File file)
{
InputStream mInput = null;
FileOutputStream mOutput = null;
if (file.getDownloadUrl() != null && file.getDownloadUrl().length() > 0) //Error occurs at file.getDownloadUrl()
{
try
{
HttpResponse resp = mDriveService.getRequestFactory().buildGetRequest(new GenericUrl(file.getDownloadUrl())).execute();
mInput = resp.getContent();
String outFileName = "file://" + Environment.getDataDirectory().getPath() + filePath;
// Log.e("com.example.myapp", "getDatabasePath="+ getDatabasePath(""));
//Log.e("com.example.myapp", "outFileName="+outFileName);
// String outFileName = "../databases/" + "Quickpay.db";
mOutput = new FileOutputStream(outFileName);
byte[] mBuffer = new byte[1024];
int mLength;
while ((mLength = mInput.read(mBuffer)) > 0)
{
mOutput.write(mBuffer, 0, mLength);
}
mOutput.flush();
}
catch (IOException e)
{
// An error occurred.
e.printStackTrace();
// return null;
}
finally
{
try
{
//Close the streams
if (mOutput != null)
{
mOutput.close();
}
if (mInput != null)
{
mInput.close();
}
}
catch (IOException e)
{
Log.e("com.example.myapp", "failed to close databases");
}
}
}
else
{
// The file doesn't have any content stored on Drive.
// return null;
Log.e("com.example.myapp", "No content on Drive");
}
}
}
}
The Gradle file is like
implementation 'com.google.android.gms:play-services-auth:16.0.1'
implementation('com.google.apis:google-api-services-drive:v3-rev136-1.25.0')
{
exclude group: 'org.apache.httpcomponents'
}
implementation('com.google.api-client:google-api-client-android:1.26.0')
{
exclude group: 'org.apache.httpcomponents'
}
implementation 'com.google.http-client:google-http-client-gson:1.26.0'
As far as i know Download URL is only avalibale in Google drive api v2 and not in V3.
Short lived download URL for the file. This field is only populated for files with content stored in Google Drive; it is not populated for Google Docs or shortcut files.
It was not very stable in my opinion as not all file types would return a download url.
Using Google Drive v3 you should download the file using a stream.
String fileId = "0BwwA4oUTeiV1UVNwOHItT0xfa2M";
OutputStream outputStream = new ByteArrayOutputStream();
driveService.files().get(fileId)
.executeMediaAndDownloadTo(outputStream);
This should work with the restore. Let me know if it doesnt and i will have a look its been a while since i have tried restore.

Java File.renamTo not working

I have made the code which renames all the jpg files in a directory from 1 to n (number of files)..
if there were let say 50 jpg files that after running the program all the files are renamed to 1.jpg ,2.jpg and so on till 50.jpg
But i am facing the problem if I manually rename the file let say 50.jpg to aaa.jpg then again running the program doesn't rename that file
I have wasted one day to resove that issue
Kindly help me
Code:
public class Renaming {
private static String path; // string for storing the path
public static void main(String[] args) {
FileReader fileReader = null; // filereader for opening the file
BufferedReader bufferedReader = null; // buffered reader for buffering the data of file
try{
fileReader = new FileReader("input.txt"); // making the filereader object and paasing the file name
bufferedReader = new BufferedReader(fileReader); //making the buffered Reader object
path=bufferedReader.readLine();
fileReader.close();
bufferedReader.close();
}
catch (FileNotFoundException e) { // Exception when file is not found
e.printStackTrace();
}
catch (IOException e) { // IOException
e.printStackTrace();
}
finally {
File directory=new File(path);
File[] files= directory.listFiles(); // Storing the all the files in Array
int file_counter=1;
for(int file_no=0;file_no<files.length;file_no++){
String Extension=getFileExtension(files[file_no]); //getting the filw extension
if (files[file_no].isFile() && (Extension .equals("jpg")|| Extension.equals("JPG"))){ // checking that if file is of jpg type then apply renaming // checking thaat if it is file
File new_file = new File(path+"\\"+files[file_no].getName()); //making the new file
new_file.renameTo(new File(path+"\\"+String.valueOf(file_no+1)+".jpg")); //Renaming the file
System.out.println(new_file.toString());
file_counter++; // incrementing the file counter
}
}
}
}
private static String getFileExtension(File file) { //utility function for getting the file extension
String name = file.getName();
try {
return name.substring(name.lastIndexOf(".") + 1); // gettingf the extension name after .
} catch (Exception e) {
return "";
}
}`
first of all, you should use the path separator / . It's work on Windows, Linux and Mac OS.
This is my version of your problem to rename all files into a folder provide. Hope this will help you. I use last JDK version to speed up and reduce the code.
public class App {
private String path = null;
public static int index = 1;
public App(String path){
if (Files.isDirectory(Paths.get( path ))) {
this.path = path;
}
}
public void rename() throws IOException{
if ( this.path != null){
Files.list(Paths.get( this.path ))
.forEach( f ->
{
String fileName = f.getFileName().toString();
String extension = fileName.replaceAll("^.*\\.([^.]+)$", "$1");
try {
Files.move( f ,Paths.get( this.path + "/" + App.index + "." + extension));
App.index++;
} catch (IOException e) {
e.printStackTrace();
}
}
);
}
}
public static void main(String[] args) throws IOException {
App app = new App("c:/Temp/");
app.rename();
}
}

File Not Found Exception : Open failed:ENOENT

I am new for android, Im downloading image from URL and set in listView. Its working some mobile and not creating file/directory in some mobile.
Its throw error like:
java.io.FileNotFoundException: /storage/emulated/0/.tam/veg.png: open failed: ENOENT (No such file or directory)
I don't know why its throw error like this some mobile. I want to create directory all type of mobile. Please anyone help me.
Here my code:
public class ImageStorage {
public static String saveToSdCard(Bitmap bitmap, String filename) {
String stored = null;
File sdcard = Environment.getExternalStorageDirectory();
File folder = new File(sdcard.getAbsoluteFile(), ".tam");//the dot makes this directory hidden to the user
folder.mkdir();
File file = new File(folder.getAbsoluteFile(), filename) ;
if (file.exists())
return stored ;
try {
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();
stored = "success";
} catch (Exception e) {
e.printStackTrace();
}
return stored;
}
public static File getImage(String imagename) {
File mediaImage = null;
try {
String root = Environment.getExternalStorageDirectory().getAbsolutePath();
File myDir = new File(root);
if (!myDir.exists())
return null;
mediaImage = new File(myDir.getPath() + "/.tam/"+imagename);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return mediaImage;
}
public static File checkifImageExists(String imagename) {
File file = ImageStorage.getImage("/" + imagename);
if (file.exists()) {
return file;
} else {
return null;
}
}
public static String getImageName(String value){
String getName[] = value.split("/");
return getName[4];
}
}
Below path not in all mobile:
/storage/emulated/0/
Thanks in advance!!
Maybe u should check if there's external storage in the mobile before u use this path
public String getDir(Context context) {
String checkPath = null;
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())
|| !Environment.isExternalStorageRemovable()) {
checkPath = Environment.getExternalStorageDirectory().getPath();
} else {
checkPath = context.getCacheDir().getPath();
}
return checkPath;
}

How to check image exist in a particular location?

Is there any way to check image exist in a particular location except the following code?This code is taking too much time.
static boolean isImage(String image_path){
InputStream input = null;
try{
URL url = new URL(image_path);
input = url.openStream();
return true;
}catch(Exception ex){
return false;
}
}
If you just want to check if the file exists:
static boolean isImage(String image_path){
try{
File f = new File(image_path);
return f.exists();
}catch(Exception ex){
return false;
}
}

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