Develop Reference

How to create sub folders under cache of an application using getExternalCacheDir()?

In my application I want to save some documents in my application cache. After use I want to clear that files from cache. If I clear the cache all saved data's will be loss but I don't want that. I need to create a sub folder under my cache and I want to read data's from that cache folder also after certain uses I wanted to clear data's present in that particular folder.
How can I do that using getExternalCacheDir()?
I tried using following snippet,
File tempFile = new File(AppDelegate.sharedDelegate().getExternalCacheDir()+"\documentfolder\", name + ext);
OutputStream outputStream = new FileOutputStream(tempFile);
IOUtils.copy(inputStream, outputStream);
outputStream.close();
return tempFile;
But I am getting
System.err: java.io.FileNotFoundException: /storage/emulated/0/Android/data/com.package.debug/cache/documentcache/Screenshot_20171108-011217.png.png (No such file or directory)
W/System.err: at java.io.FileOutputStream.open(Native Method)
W/System.err: at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
W/System.err: at java.io.FileOutputStream.<init>(FileOutputStream.java:169)
How can I solve it?

getCacheDir(). It returns the absolute path to the application specific cache directory
File myDir = new File(getCacheDir(), "yourfolder");
myDir.mkdir();
then create file using below code.
File f = new File(your directyorypath + "filename.txt");
if (f.exists())
{
f.delete();
}
f.createNewFile();

This should work:
File dir = new File(AppDelegate.sharedDelegate().getExternalCacheDir(), "documentfolder");
dir.mkdirs();
then use dir as parent folder for your file:
File tempFile = new File(dir, name + ext);
OutputStream outputStream = new FileOutputStream(tempFile);
IOUtils.copy(inputStream, outputStream);
outputStream.close();
return tempFile;

FileNotFoundException : Can't Open file, file not found in Android

I am going to create one .pdf file and I am getting file not found exception. I have written WRITE_EXTERNAL_STORAGE permission for that in AndroidManifest.xml file and also provided runtime permission for Marshmallow device.
Below is my code:
File SDCardRoot = Environment.getExternalStorageDirectory();
//create a new file, to save the downloaded file
File file = new File(SDCardRoot + "xyz/", pdfFilename);
if (!file.exists()) {
file.mkdir();
}
OutputStream fileOutput = new FileOutputStream(file);
docWriter = PdfWriter.getInstance(doc, fileOutput);
Can you please get me out?

Writing File in External SD card in android

I have tried so many ways to write file in external as card but not working. Please suggest me what to do.
The code snippet that I wrote is as follows:
final String directoryFile = "file:///"+"mnt/extsd/Test";
String filename = "TextData.txt";
Context context;
//String file=Environment.getExternalStorageDirectory()+ "/TextData.txt";
//String file = "mnt/extsd/TextData.txt";
//String file=Environment.getExternalStorageDirectory()+ "/RudimentContent/test.txt";
//File root = android.os.Environment.getExternalStorageDirectory();
//File dir = new File (root.getAbsolutePath() + "/download");
//File path = Environment.getExternalStorageDirectory();
//String filename = "TextData.txt";
//String fileName = "TextData.txt";
//String path = "Environment.getExternalStorageDirectory()/TextData.txt";
//File path = Environment.getExternalStorageDirectory();
public void onClick(View v)
{
// write on SD card file data in the text box
// dir.mkdirs();
//File file = new File(dir, "myData.txt");
//String fileName = surveyName + ".csv";
//String headings = "Hello, world!";
//File file = new File(path, fileName);
//path.mkdirs();
//OutputStream os = new FileOutputStream(file);
//os.write(headings.getBytes());
//create path
//create file
//File outFile = new File(Environment.getExternalStorageDirectory(), filename);
//File directoryFile = new File("mnt/extsd", "Test");
//directoryFile.mkdirs();
//create file
//File file = new File(Environment.getExternalStorageDirectory(), filename);
try{
File myFile = new File(directoryFile, filename); //device.txt
myFile.createNewFile();
FileOutputStream fOut = new FileOutputStream(myFile);
OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);
myOutWriter.append(txtData.getText());
myOutWriter.close();
fOut.close();
Toast.makeText(getBaseContext(),"Done writing SD "+myFile.getPath(),Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
});
I have commented on so may tried codes also. When I write in internal sd card then its working but not with external. Please suggest.

I had this before.
The reason you're having this exception is due to some bizarre ways the framework handles files and folders.
on my case was that I was testing, and all was working, and I deleted the testing folder and since then the system keeps trying to write on the deleted folder. I removed the project from the phone and reboot it and started working again.
furthermore, I suggest you a quick reading on this answer What is the best way to create temporary files on Android? and the comments of this answer... as there is a lot of useful information if you want to create a good app.

just set permission like this
android.permission.WRITE_EXTERNAL_STORAGE

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 and DIRECTORY_RINGTONES (pass null to receive the root of your application's file directory).
This method will create the appropriate directory if necessary.
If you're using API Level 7 or lower, use getExternalStorageDirectory(), to open a File representing the root of the external storage. You should then write your data in the following directory:
/Android/data//files/
You will have to set the permissions too:
android.permission.WRITE_EXTERNAL_STORAGE

try this
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try {
FileOutputStream out = new FileOutputStream(file);
finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
and add this in manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
EDIT: By using this line you can able to see stores images in the gallery view.
sendBroadcast(new Intent(
Intent.ACTION_MEDIA_MOUNTED,
Uri.parse("file://" + Environment.getExternalStorageDirectory())));

Android - downloading file, java.io.FileNotFoundException

I may be way off here, but I am trying to download a file and store it in the downloads folder on my phone. I am getting a "java.io.FileNotFoundException" error, because the file doesn't exist, because I'm trying to download it...what am I doing wrong?
String PATH = Environment.getExternalStorageDirectory() + "/download/";
File dir = new File(PATH);
dir.mkdirs();
File outputFile = new File(dir, "downloadFile");
FileOutputStream fos = new FileOutputStream(outputFile);
This fails, with the following:
java.io.FileNotFoundException: /mnt/sdcard/download/downloadFile (Permission denied)
I am using the WRITE_EXTERNAL_STORAGE and READ_EXTERNAL_STORAGE permissions....

Please try following updated code,
String PATH = Environment.getExternalStorageDirectory() + "/download";
File dir = new File(PATH);
dir.mkdirs();
File outputFile = new File(dir, "downloadFile");
if ( !outputFile.exists() )
{
outputFile.create();
}
FileOutputStream fos = new FileOutputStream(outputFile);
There is a "/" after the download. This way Android is thinking that you are creating Recursive Directory. While using mkdirs(), you can not create recursive directories.
You can also check my answer for same in Java ME here.

Add Permission to write external memory in your Manifest file.
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Here you want to make directoy?
it there is already folder of download than use this code directly.
// create a File object for the parent directory
File Directory = new File("/sdcard/download/");
Directory.mkdirs();
// create a File object for the output file
File outputFile = new File(Directory, downloadFile);
// now attach the OutputStream to the file object, instead of a String representation
FileOutputStream fos = new FileOutputStream(outputFile);
It might be wise to use Environment.getExternalStorageDirectory() for getting the "SD Card" directory as this might change

Folder created instead of a file

I want to create a file in a defined directory, i tried this two codes but the first just creates folders and the other output an exception: no such file or directory:
First code:
File file = new File(Environment.getExternalStorageDirectory()
+File.separator
+"carbu"
+File.separator
+"install");
file.mkdir();
Then i added this code hopefully to create the file:
File file2 = new File("/carbu/install/","voitu");
file2.createNewFile();
Can anyone please try to help me ?
Thank you very much :).

Try this in your Activity:
FileOutputStream fos = openFileOutput(YOUR_FILE_NAME, Context.MODE_PRIVATE);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeInt(5);
oos.flush();
This will create file if it isn't exist. Of course you should close oos and fos.

Here is the most simple solution, working at 100% ;)
File dir = new File (sdCard.getAbsolutePath() + "/jetpack/install");
dir.mkdirs();
File file = new File(dir, "wipe");

have you tried:
File f=new File("myfile.txt");
if(!f.exists())
{
f.createNewFile();
}
In you example you are only giving the pathname to the file but you are not defining the type and the name of the new file.
http://download.oracle.com/javase/6/docs/api/java/io/File.html
Also try following:
String FILENAME = "/carbu/install/test.txt";
String string = "hello world!";
FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(string.getBytes());
fos.close()
got the above example from: http://developer.android.com/guide/topics/data/data-storage.html

try {
File root = Environment.getExternalStorageDirectory();
if (root.canWrite()){
File gpxfile = new File(root, "gpxfile.gpx");
FileWriter gpxwriter = new FileWriter(gpxfile);
BufferedWriter out = new BufferedWriter(gpxwriter);
out.write("Hello world");
out.close();
}
} catch (IOException e) {
Log.e(TAG, "Could not write file " + e.getMessage());
}

While you were careful in constructing the path correctly in the first segment, you just hard-coded the wrong path in the second part. Ensure you use the correct path, possibly as follows:
String path = Environment.getExternalStorageDirectory().getAbsolutePath()
+File.separator
+"carbu"
+File.separator
+"install";
File file = new File(path);
file.mkdir();
File file2 = new File(path + File.separator + "voitu");
file2.createNewFile();