Develop Reference

how to create folder and file in storage directory in android

I wanted to create some folders and some files to /storage/MyFolder/.
I had tried to work on using /storage/emulated/0/MyFolder and it is working but i want to make hide under the storage root folder.
Is there any possible way for me to do this?

You can create folder like this in External Storage directory:
String folder_main = "NewFolder";
File f = new File(Environment.getExternalStorageDirectory(), folder_main);
if (!f.exists()) {
f.mkdirs();
}

//get path to external storage (SD card)
String iconsStoragePath = Environment.getExternalStorageDirectory() + "/Abc/";
File sdIconStorageDir = new File(iconsStoragePath);
//create storage directories, if they don't exist
if(!sdIconStorageDir.exists()){
sdIconStorageDir.mkdirs();
}

How can we create a folder of app in device storage in Android?

I'm using code in comment to save a file in directory folder. This code is working properly with mobile phone having sd card.
But if I use it with mobile phone not having sd card it is giving IO exception.
How can I create a folder like whatsapp has in device storage root to save images etc but I want a folder of application name to save .csv files in my device storage root.

First make sure you have added Storage Permissions inside Manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
If you want to create folder inside ExternalDirectory
File f = new File(Environment.getExternalStorageDirectory()+"/foldername");
if(!f.exists()) f.mkdir();
If you want to create file inside internal storage
File mydir = context.getDir("mydir", Context.MODE_PRIVATE); //Creating an internal directory;
File fileWithinMyDir = new File(mydir, "myfile");
FileOutputStream out = new FileOutputStream(fileWithinMyDir);

You can create directory in internal storage and external storage as Follows.
//check whether Sdcard present or not
Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
if(isSDPresent)
{
// yes SD-card is present
String directory = "/your Directory name or app name ";
String path = Environment.getExternalStorageDirectory().getAbsolutePath() + directory;
File dir = new File(path);
if(!dir.exists()) //check if not created then create the firectory
dir.mkdirs();
//add your files in directory as follows
File file = new File(dir, filename);
}
else
{
// create folder in internal memory
File mydir = context.getDir(directory, Context.MODE_PRIVATE); //Creating an internal directry
if(!mydir.exists()) //check if not created then create the firectory
mydir.mkdirs();
//add your files in directory as follows
File file = new File(mydir, filename);
I hope it will work for you

how to create a folder internal storage in android lollipop

i have tried most of the code i have found on stack over flow read the devlopment documentation but i still fail to create a folder and a file on internal storage in android lollipop i have not tried on lower api but i even tried those internal persmission declaration in manifest.
the below sample of the code i tried do not even work for my situation:
String path = Environment.getDataDirectory().getAbsolutePath().toString() + "/storage/emulated/0/appFolder";
File mFolder = new File(path);
if (!mFolder.exists()) {
mFolder.mkdir();
}
File Directory = new File("/sdcard/myappFolder/");
Directory.mkdirs();
i tried this also below:
File myDir = context.getFilesDir();
// Documents Path
String documents = "documents/data";
File documentsFolder = new File(myDir, documents);
documentsFolder.mkdirs();
String publicC = "documents/public/api.txt" ;
File publicFolder = new File(myDir, publicC);
publicFolder.mkdirs();
and then this as well:
ContextWrapper contextWrapper = new ContextWrapper(
getApplicationContext());
File directory = contextWrapper.getDir(filepath, Context.MODE_PRIVATE);
myInternalFile = new File(directory, filename);

First, I recommend you read more on what the following terms mean with respect to Android app development:
internal storage
external storage
removable storage
With that as background, let's review what you did:
Environment.getDataDirectory().getAbsolutePath().toString() + "/storage/emulated/0/appFolder";
Never use getDataDirectory(). I have no idea where this code would point to.
File Directory = new File("/sdcard/myappFolder/");
You do not have arbitrary read/write access to removable storage, and removable storage may not be found at that location anyway.
File myDir = context.getFilesDir();
// Documents Path
String documents = "documents/data";
File documentsFolder = new File(myDir, documents);
This code is fine. However, it points to internal storage, and on Android devices, you cannot see internal storage very readily. That too is fine, as developers should be used to the idea that they cannot see everything that their code affects. You might consider writing test cases to confirm that your directory was created.
String publicC = "documents/public/api.txt" ;
File publicFolder = new File(myDir, publicC);
This points to nowhere. Always use some method to derive the base path.
ContextWrapper contextWrapper = new ContextWrapper(
getApplicationContext());
File directory = contextWrapper.getDir(filepath, Context.MODE_PRIVATE);
myInternalFile = new File(directory, filename);
The ContextWrapper is useless. filepath needs to be a simple directory name. You could simplify this as:
File directory = getDir(directoryName, Context.MODE_PRIVATE);
myInternalFile = new File(directory, filename);
Then this code is also fine. It too points to internal storage, and therefore you will not be able to examine it directly. Once again, write test code to confirm that the directory was created as you expect.

How to Store a File in our sd card that we have inserted

I am trying to save a file in my External SDcard but the file is getting stored in internal storage. How to store the file in the SDcard inserted
mr = new MediaRecorder();
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)){
Log.e("aa","sss");
cameraFolder = new File(android.os.Environment.getExternalStorageDirectory(), "Recorder");
} else {
cameraFolder= getDir("Recorder",MODE_PRIVATE);
}
if(!cameraFolder.exists()) {
cameraFolder.mkdir();
}
fname = cameraFolder + "/myrec1.MPEG_4";

There is already a similar question here, you can also find more detailed information on the android docs
As suggested in a comment below I'll improve this answer.
In order to save a file to a specific position in your SD card you need to create a File object which points to that position:
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath() + "/your/file/directory");
dir.mkdirs();
File file = new File(dir, "filename");
and then use a FileOutputStream to write the content.
Remember that you need to add the required permission in the manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Saving file in sd card without extension and access that with extension

I am downloading a pdf file from server and saving it on sd card without extension (for security purpose so that normal user can't open that file from file manager).For e.g.- I am downloading abc.pdf and saving it on sd card with abc on below path
String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
File folder = new File(extStorageDirectory, "files");
And later I want to view that file by adding extension.
So when I am accessing that file from code by using below code then its gives error file does't exist..
String s=Environment.getExternalStorageDirectory() + "/files/" + "abc";
File pdfFile = new File(s+".pdf");
So how can I save file in sd card without extension and later open that file with extension.

Workaround for your problem is to rename your saved pdf file without extension to filename with .pdf extension & after completing/accessing view or read operation on your new pdf extension file again you can rename it to file without extension
Example Usage:
String currentFileName = Environment.getExternalStorageDirectory() + File.separator
+ "files" + File.separator + "abc";
String renamedFilename = currentFileName + ".pdf";
boolean isRenamed = renameFile(currentFileName, renamedFilename);
Log.d("isRenamed: ", "" + isRenamed);
if(isRenamed {
//perform your operation
}
Again rename the file if not in use (here exchange renameFile() parameters):
boolean renameAfterOperation = renameFile(renamedFilename, currentFileName);
Log.d("renameAfterOperation : ", "" + renameAfterOperation );
And here is renameFile(currentFilePath, renamedFilePath):
public boolean renameFile(String currentFilePath, String renamedFilePath){
File currentFile = new File(currentFilePath);
File newFile = new File(renamedFilePath);
boolean isrenamed = currentFile.renameTo(newFile);
return isrenamed;
}
In this way whenever you want to perform operation on saved file first rename it to .pdf & whenever it's not in use, again rename it without extension. Let me know if this works for you..