if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
getContentResolver().takePersistableUriPermission(data.getData(),
                        Intent.FLAG_GRANT_READ_URI_PERMISSION |
Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
}

try {
    countDownLatch = new CountDownLatch(1);
        new Thread(new Runnable() {
        @Override
            public void run() {
                try {
                    Thread.sleep(300);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                countDownLatch.countDown();
            }
        }).start();

    countDownLatch.await();

} catch (InterruptedException e) {
    e.printStackTrace();
}
target_filename= String.valueOf(System.currentTimeMillis());
treeUri = data.getData();
DocumentFile pickedDir = DocumentFile.fromTreeUri(this, treeUri);

// Create a new file and write into it
newFile = pickedDir.createFile("text", target_filename);
for(int i=0;i<10;i++){
   newFile=pickedDir.findFile(target_filename);
   int wait_sd=0;
   countDownLatch = new CountDownLatch(1);
   do{
   if(newFile.canWrite()){
               wait_sd=10;
                    }else{
                        try {
                            countDownLatch.await(500, TimeUnit.MILLISECONDS);
                            wait_sd++;
                        } catch (InterruptedException e) {
                            // TODO 自動生成された catch ブロック
                            e.printStackTrace();
                        }
                    }
                }while(wait_sd<10);

            }