How to Create a File in Android

How to create files to a specific folder in android application?

use getCacheDir(). It returns the absolute path to the application-specific cache directory on the filesystem. Then you can create your directory

File myDir = new File(getCacheDir(), "folder");
myDir.mkdir();

Please try this maybe helps you.

Ok, If you want to create the TextFile in Specific Folder then You can try to below code.

try {
        String rootPath = Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "/MyFolder/";
        File root = new File(rootPath);
        if (!root.exists()) {
            root.mkdirs();
        }
        File f = new File(rootPath + "mttext.txt");
        if (f.exists()) {
            f.delete();
        }
        f.createNewFile();

        FileOutputStream out = new FileOutputStream(f);

        out.flush();
        out.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

Android how to create a new file for each download?

You are assigning the same name to every file you create. Try giving a unique name like this:

UUID uuid = UUID.randomUUID();
String randomUUIDString = uuid.toString();

the randomUUIDString will be your unique string for the pdf files. Also, store these strings in a SQLite db if you wish to use them.

How to create text file and insert data to that file on Android

Using this code you can write to a text file in the SDCard.
Along with it, you need to set a permission in the Android Manifest.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

This is the code :

public void generateNoteOnSD(Context context, String sFileName, String sBody) {
    try {
        File root = new File(Environment.getExternalStorageDirectory(), "Notes");
        if (!root.exists()) {
            root.mkdirs();
        }
        File gpxfile = new File(root, sFileName);
        FileWriter writer = new FileWriter(gpxfile);
        writer.append(sBody);
        writer.flush();
        writer.close();
        Toast.makeText(context, "Saved", Toast.LENGTH_SHORT).show();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Before writing files you must also check whether your SDCard is mounted & the external storage state is writable.

Environment.getExternalStorageState()

Android: how to write a file to internal storage

Use the below code to write a file to internal storage:

public void writeFileOnInternalStorage(Context mcoContext, String sFileName, String sBody){      
    File dir = new File(mcoContext.getFilesDir(), "mydir");
    if(!dir.exists()){
        dir.mkdir();
    }

    try {
        File gpxfile = new File(dir, sFileName);
        FileWriter writer = new FileWriter(gpxfile);
        writer.append(sBody);
        writer.flush();
        writer.close();
    } catch (Exception e){
        e.printStackTrace();
    }
}

Starting in API 19, you must ask for permission to write to storage.

You can add read and write permissions by adding the following code to AndroidManifest.xml:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

You can prompt the user for read/write permissions using:

requestPermissions(new String[]{WRITE_EXTERNAL_STORAGE,READ_EXTERNAL_STORAGE}, 1);

and then you can handle the result of the permission request in onRequestPermissionsResult() inside activity called from it.

Creating a File object from a resource

This is what I ended up doing:

try{
  InputStream inputStream = getResources().openRawResource(R.raw.some_file);
  File tempFile = File.createTempFile("pre", "suf");
  copyFile(inputStream, new FileOutputStream(tempFile));

  // Now some_file is tempFile .. do what you like
} catch (IOException e) {
  throw new RuntimeException("Can't create temp file ", e);
}

private void copyFile(InputStream in, OutputStream out) throws IOException {
    byte[] buffer = new byte[1024];
    int read;
    while((read = in.read(buffer)) != -1){
      out.write(buffer, 0, read);
    }
}