Develop Reference

Creating a directory on external sd card that will have a text file written to it

I am trying to create a folder on my external SDcard that will contain a text file that I can pull off my phone from my PC and read it.
I have pieced together a snippet that I believe should work, but I cannot find the folder that is supposedly being created.
File path = Environment.getExternalStorageDirectory();
File dir = new File(path.getAbsolutePath() + "/iptestdata/");
if (!dir.exists()) {
dir.mkdirs();
}
String fileName = new SimpleDateFormat("yyyyMMddHHmmss'.txt'").format(new Date());
final File file = new File(dir, fileName);
As I am stepping though the debugger in Android Studio, I see the path being created and stored in dir is /storage/emulated/0/iptestdata, and I see the file name appearing in the format that I requested, but I cannot find the file via File Explorer in Windows. How can I fix this?

If you create File and store into storage Directory you want to call mkdirs()
File sdcard = Environment.getExternalStorageDirectory();
File dir = new File(sdcard.getAbsolutePath() + " /dir - name /");
dir.mkdir();
File file = new File(dir, "File-Name.txt");
FileOutputStream os = outStream = new FileOutputStream(file);
String data = "This is the content of my file";
os.write(data.getBytes());
os.close();
Please check the Directory is created or not the following method
public static boolean canWriteOnExternalStorage() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
Log.v("Activity", "Yes, can write to external storage.");
return true;
}
return false;
}
Add Permission in your AndroidManifest.xml
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

android read/save internal storage

I need to save file into internal storage, an then read it.
For save it i do something like this:
// Create directory into internal memory;
File mydir = getActivity().getDir("modelli", Context.MODE_PRIVATE);
File a = new File(mydir, obj_id);
a.mkdir();
File b = new File(mydir, obj_id);
if (obj_type != "modello"){
b = new File(a,obj_type);
b.mkdir();
}
String filename = "";
if(obj_imageName != null)
{
filename = obj_imageName + "." + getFileExtension(urlString);
}
else
{
filename = getFileName(urlString);
}
final File file = new File(b, filename);
file.createNewFile();
but I don't know how read it, with this I get an error (contains a path separator):
File mydir = getActivity().getDir("app_modelli/2/images", Context.MODE_PRIVATE);
where is the mistake? is correct my approach for write file?

You better put them in internal files dir. Both for writing and reading you could use a File object like:
String fileName = "info.txt";
File file = new File ( getInternalFilesDir() + "/" + fileName);
At the moment your code only creates a file with length 0. You are not writing/saving anything to it.

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: how to set the path for saving files etc like in windows we write c:/someting/...what will I do in android

I am trying to record voice and save it in a file. For this I have to give a path to save the file, but I don't know how will I set the path...I have recently started working on android phone. In windows we set path like a drive e.g. C:/folder/folder....in android phone what will be my root? Where can I save an audio file? Write now I am working on emulator...Will the path be same for both emulator and phone?

we can create file like this in SD card
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/folder");
myDir.mkdirs();
String fname = "file";
File file = new File (myDir, fname);
file is the path of file where you stored.
and add this Permission in manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

_path=Environment.getExternalStorageDirectory().getPath() + "/RECORDS/";
// || ||
// VV VV
// storage path folder name
fileName = String.format("filename.mp3");
File file = new File(_path, fileName);
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}

Save your file in Sdcard.
File path = Environment.getExternalStorageDirectory();
String cardName = path.getName();
path=cardName+"/mypathname/file_name.mp3";
It is also possible in emulator. create sdcard , when you create emulator.
Thanks

Uri outputFileUri;
File root = new File(Environment.getExternalStorageDirectory()
+ File.separator + "myDir" + File.separator);
root.mkdirs();
sdImageMainDirectory = new Filenter code here(root, "myPicName.jpg");
outputFileUri = Uri.fromFile(sdImageMainDirectory);

How to check if a file exists in a directory in sd card

I want to check whether a given file exists in android sd card. I am trying it out with creating a file using the absolute path and checking with file.exists() but its not working. The URL for the file is "file:///mnt/sdcard/book1/page2.html" and the file does exist. But somehow file.exists() isn't showing the same.

File extStore = Environment.getExternalStorageDirectory();
File myFile = new File(extStore.getAbsolutePath() + "/book1/page2.html");
if(myFile.exists()){
...
}
This should work.

Try like this:
File file = new File(Environment.getExternalStorageDirectory() + "/book1/page2.html");
if (file.exists()) {
/*...*/
}
Also make sure you have:
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
in your manifest file.

You can check as follows:
File file = new File(getExternalCacheDirectory(), "mytextfile.txt" );
if (file.exists()) {
//Do action
}

File logFile = new File(
android.os.Environment.getExternalStorageDirectory()
+ "/book1/", "page2.tml");
if (logFile.exists())
System.out.println("file exists");
else
System.out.println("file does not exist

Do something like this :
File dir = Environment.getExternalStorageDirectory();
File yourFile = new File(dir, "your/file/path");
if(yourFile.exists())
{
}

String filepath = getFilesDir().getAbsolutePath();
String FileName = "Yourfilename" ;
File FileMain = new File(filepath, FileName);
if (FileMain.exists()){
do somthing here
}else{}

File file = new File(path+filename);
if (file.exists())
{
//Do something
}
checked, this will work