Develop Reference

Is there a way to use Tesseract OCR for Java without specifying the path of the image?

I am currently creating a spring boot application that allows the user to store a database of books to organize and search throughout. I have added a feature within the addition portion of the application that uses Tesseract OCR to scan an image of a book cover to extract as much information as it can so the user can copy paste the title and author over to the addition text boxes. I want this to be used by users from their own computers but I'm not sure how to set up the File system so that it can read from the input source instead of the code being changed. Code below...
bookScanner.java
import java.io.File;
import net.sourceforge.tess4j.*;
public class bookScanner {
public String booksScanner() {
File imageFile = new File("\path\to\file\book.jpg");
//Change Datapath based off of computer
ITesseract instance = new Tesseract();
instance.setDatapath("\path\to\file");
try {
String result = instance.doOCR(imageFile);
return result;
}
catch (TesseractException e) {
System.err.println(e.getMessage());
return "";
}
}
}
File imageFile = new File("\path\to\file"); This snippet right here is the problem. I don't want this to be hardcoded because a foreign user may have the image labeled as BookCover and it might be a png or jpeg and it won't scan.
FIXED
I used a file reading system to access and read the newest submitted file and it all works as intended now if anyone has troubles with this later on, here is the following code...
File folder = new File("\path\to\file");
File[] listOfFiles = folder.listFiles();
long lastModifiedTime = Long.MIN_VALUE;
File chosenFile = null;
if (listOfFiles != null) {
for (File file: listOfFiles) {
if (file.lastModified() > lastModifiedTime) {
chosenFile = file;
lastModifiedTime = file.lastModified();
if (chosenFile.isFile()) {
chosenFile = new File("\path\to\file" + file.getName());
System.out.println(chosenFile);
}
}
}
}

How to delete a file from storage using file's path?

I am working on an app that list all the audio files from shared internal storage and removable SD card.
Now if the user wants to delete a particular file , it will be deleted from shared internal storage or removable SD card.
The issue I am facing is file.delete does not work , I have used mediastore to get all audio files.
These were the audio file paths i got from media store.
This is from internal shared storage.
/storage/emulated/0/Music/Guitar1.mp3
This is from removable micro SD card.
/storage/BBF8-A8D3/Guitar1.mp3
After getting these paths
File deleteFile = new File(s.getFilepath());
boolean delete = deleteFile.delete();
The delete gives false as delete file is not deleted.
Now I have tried this,
File deleteFile = new File(s.getFilepath());
if(deleteFile.exists()) {
boolean catchdelete = deleteFile.delete();}
Now after creating file from path , if condition fails as delete File does not exist.
So why newly created file does not exist(file is not a directory) does it require file input stream.
My main issue is to delete a file from storage through the app.
This is my method for retreiving audio file paths
public ArrayList<String> getAudiosPath(Activity activity, Context context) {
// Uri uri;
listOfAllAudios = new ArrayList<String>();
Cursor cursor;
final String[] columns = {MediaStore.Audio.Media.DATA, MediaStore.Audio.Media._ID};
final String orderBy = MediaStore.Audio.Media._ID;
//Stores all the audio from the gallery in Cursor
cursor = getContentResolver().query(
MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, columns, null,
null, orderBy);
//Total number of audios
int count = cursor.getCount();
//Create an array to store path to all the audios
String[] arrPath = new String[count];
for (int i = 0; i < count; i++) {
cursor.moveToPosition(i);
int dataColumnIndex = cursor.getColumnIndex(MediaStore.Audio.Media.DATA);
//Store the path of the audio
arrPath[i] = cursor.getString(dataColumnIndex);
Bitmap b = ((BitmapDrawable) ResourcesCompat.getDrawable(context.getResources(), R.drawable.headphone512, null)).getBitmap();
bitmap.add(b);
Log.i("PATH", arrPath[i]);
listOfAllAudios.add(arrPath[i]);
}
// count_paths=listOfAllAudios.size();
return listOfAllAudios;
}
Now i have applied Apache Commons IO File Utils
File deleteFile = new File(s.getFilepath());
// boolean delete = deleteFile.delete();
try {
FileUtils.forceDelete(FileUtils.getFile(s.getFilepath()));
}
catch (IOException e) {
e.printStackTrace();
}
This Apache Commons file utils does delete the file but issue is when opening the app again i am seeing the file path with file size 0 KB.
In Download Nav drawer
when in Nav drawer i access TA-1032-> Music -> Empty(No File present)
(there is no file which means file gets deleted)
But in Nav drawer i access Audio-> Unknown -> Music -> Guitar.mp3 (file present but file size is 0 and cant be played)
so this is some how getting the path of file.

Try using Apache Commons as a dependency and use their file API for the operation.
FileUtils.forceDelete(FileUtils.getFile(s.getFilepath()));

This piece might work.
Files.deleteIfExists(Paths.get("C:\\Users\\Mayank\\Desktop\\
445.mp3"));

Code snip will be helpful
File directory = new File("c:\\directoryname\\filename.txt");-- give your path where file is located.
try {
FileUtils.forceDelete(directory);
System.out.println("force delete file in java");
}
catch (IOException e) {
e.printStackTrace();
}

This worked for me , the code posted by #dammina deleted the file but still was accessible from media store so the other method will take care of it.
File deleteFile = new File(s.getFilepaths());
try {
FileUtils.forceDelete(FileUtils.getFile(s.getFilepaths()));
// adapterRecycler.notifyDataChanged();
adapterRecycler.notifyDataChanged(sectionHeaders);
}
catch (IOException e) {
e.printStackTrace();
}
deleteFileFromMediaStore(getContentResolver(), deleteFile);
method for deleting from media store because even after deleting file it is still accessible through media store.
public static int deleteFileFromMediaStore(final ContentResolver contentResolver, final File file) {
String canonicalPath;
try {
canonicalPath = file.getCanonicalPath();
} catch (IOException e) {
canonicalPath = file.getAbsolutePath();
}
// MediaStore.Files.FileColumns.DATA
final Uri uri = MediaStore.Files.getContentUri("external");
final int result = contentResolver.delete(uri,
MediaStore.Audio.Media.DATA + "=?", new String[]{canonicalPath});
if (result == 0) {
final String absolutePath = file.getAbsolutePath();
if (!absolutePath.equals(canonicalPath)) {
int deletedRow = contentResolver.delete(uri,
MediaStore.Audio.Media.DATA + "=?", new String[]{absolutePath});
return deletedRow;
}
} else return result;
return result;
}

Android: how to write a file to internal storage

I am developing a simple android application and I need to write a text file in internal storage device. I know there are a lot of questions (and answers) about this matter but I really cannot understand what I am doing in the wrong way.
This is the piece of code I use in my activity in order to write the file:
public void writeAFile(){
String fileName = "myFile.txt";
String textToWrite = "This is some text!";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(fileName , Context.MODE_PRIVATE);
outputStream.write(textToWrite.getBytes());
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
I really cannot understand which mistake I am doing. In addition, I have tried this project on my emulator in Android Studio and my phone in order to understand where I am doing something wrong but even with that project no file is written neither on the phone or on the emulator.
EDIT:
I know that no file is written to my internal storage because I try to read the content of the file, after I have written to it, with this code:
public void ReadBtn(View v) {
//reading text from file
try {
FileInputStream fileIn=openFileInput("myFile.txt");
InputStreamReader InputRead= new InputStreamReader(fileIn);
char[] inputBuffer= new char[READ_BLOCK_SIZE];
String s="";
int charRead;
while ((charRead=InputRead.read(inputBuffer))>0) {
String readstring=String.copyValueOf(inputBuffer,0,charRead);
s +=readstring;
}
InputRead.close();
textmsg.setText(s);
} catch (Exception e) {
e.printStackTrace();
}
}
Nothing is shown at all.

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.

no file is written neither on the phone or on the emulator.
Yes, there is. It is written to what the Android SDK refers to as internal storage. This is not what you as a user consider to be "internal storage", and you as a user cannot see what is in internal storage on a device (unless it is rooted).
If you want to write a file to where users can see it, use external storage.
This sort of basic Android development topic is covered in any decent book on Android app development.

Save to Internal storage
data="my Info to save";
try {
FileOutputStream fOut = openFileOutput(file,MODE_WORLD_READABLE);
fOut.write(data.getBytes());
fOut.close();
Toast.makeText(getBaseContext(), "file saved", Toast.LENGTH_SHORT).show();
}
catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Read from Internal storage
try {
FileInputStream fin = openFileInput(file);
int c;
String temp="";
while( (c = fin.read()) != -1){
temp = temp + Character.toString((char)c);
}
tv.setText(temp);
Toast.makeText(getBaseContext(), "file read", Toast.LENGTH_SHORT).show();
}
catch(Exception e){
}

Android 11 Update
Through Android 11 new policies on storage, You cannot create anything in the root folder of primary external storage using Environment.getExternalStorageDirectory() Which is storage/emulated/0 or internal storage in file manager. The reason is that this possibility led to external storage being just a big basket of random content. You can create your files in your own applications reserved folder storage/emulated/0/Android/data/[PACKAGE_NAME]/files folder using getFilesDir() but is not accessible by other applications such as file manager for the user! Note that this is accessible for your application!
Final solution (Not recommended)
By the way, there is a solution, Which is to turn your application to a file manager (Not recommended). To do this you should add this permission to your application and the request that permission to be permitted by the user:
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" />
Thoriya Prahalad has described how to this job in this stackoverflow post.

To view files on a device, you can log the file location >provided by methods such as File.getAbsolutePath(), and >then browse the device files with Android Studio's Device >File Explorer.
I had a similar problem, the file was written but I never saw it. I used the Device file explorer and it was there waiting for me.
String filename = "filename.jpg";
File dir = context.getFilesDir();
File file = new File(dir, filename);
try {
Log.d(TAG, "The file path = "+file.getAbsolutePath());
file.createNewFile();
} catch (Exception e) {
e.printStackTrace();
}
return true;

Have you requested permission to write to external storage?
https://developer.android.com/training/basics/data-storage/files.html#GetWritePermission
Perhaps your try\catch block is swallowing an exception that could be telling you what the problem is.
Also, you do not appear to be setting the path to save to.
e.g: Android how to use Environment.getExternalStorageDirectory()

To write a file to the internal storage you can use this code :
val filename = "myfile"
val fileContents = "Hello world!"
context.openFileOutput(filename, Context.MODE_PRIVATE).use {
it.write(fileContents.toByteArray())
}

This Answer worked for me for android 11+ !! check it out, hopefully it'll work for you too
https://stackoverflow.com/a/66366102/16657358[1]
[(btw, int SDK_INT = 30; it confused me lol so thought i should mention)]

Intelligently serving jar files from a web server

I am writing a simple (generic) wrapper Java class that will execute on various computers separate from a deployed web server. I want to download the latest version of a jar file that is the application from that associated Web Server (currently Jetty 8).
I have code like this:
// Get the jar URL which contains the application
URL jarFileURL = new URL("jar:http://localhost:8081/myapplication.jar!/");
JarURLConnection jcl = (JarURLConnection) jarFileURL.openConnection();
Attributes attr = jcl.getMainAttributes();
String mainClass = (attr != null)
? attr.getValue(Attributes.Name.MAIN_CLASS)
: null;
if (mainClass != null) // launch the program
This works well, except that myapplication.jar is a large jar file (a OneJar jarfile, so a lot is in there). I would like this to be as efficient as possible. The jar file isn't going to change very often.
Can the jar file be saved to disk (I see how to get a JarFile object, but not to save it)?
More importantly, but related to #1, can the jar file be cached somehow?
2.1 can I (easily) request the MD5 of the jar file on the web server and only download it when that has changed?
2.2 If not is there another caching mechanism, maybe request only the Manifest? Version/Build info could be stored there.
If anyone done something similar could you sketch out in as much detail what to do?
UPDATES PER INITIAL RESPONSES
The suggestion is to use an If-Modified-Since header in the request and the openStream method on the URL to get the jar file to save.
Based on this feedback, I have added one critical piece of info and some more focused questions.
The java program I am describing above runs the program downloaded from the jar file referenced. This program will run from around 30 seconds to maybe 5 minutes or so. Then it is done and exits. Some user may run this program multiple times per day (say even up to 100 times), others may run it as infrequently as once every other week. It should still be smart enough to know if it has the most current version of the jar file.
More Focused Questions:
Will the If-Modified-Since header still work in this usage? If so, will I need completely different code to add that? That is, can you show me how to modify the code presented to include that? Same question with regard to saving the jar file - ultimately I am really surprised (frustrated!) that I can get a JarFile object, but have no way to persist it - will I even need the JarURLConnection class?
Bounty Question
I didn't initially realize the precise question I was trying to ask. It is this:
How can I save a jar file from a web server locally in a command-line program that exits and ONLY update that jar file when it has been changed on the server?
Any answer that, via code examples, shows how that may be done will be awarded the bounty.

Yes, the file can be saved to the disk, you can get the input stream using the method openStream() in URL class.
As per the comment mentioned by #fge there is a way to detect whether the file is modified.
Sample Code:
private void launch() throws IOException {
// Get the jar URL which contains the application
String jarName = "myapplication.jar";
String strUrl = "jar:http://localhost:8081/" + jarName + "!/";
Path cacheDir = Paths.get("cache");
Files.createDirectories(cacheDir);
Path fetchUrl = fetchUrl(cacheDir, jarName, strUrl);
JarURLConnection jcl = (JarURLConnection) fetchUrl.toUri().toURL().openConnection();
Attributes attr = jcl.getMainAttributes();
String mainClass = (attr != null) ? attr.getValue(Attributes.Name.MAIN_CLASS) : null;
if (mainClass != null) {
// launch the program
}
}
private Path fetchUrl(Path cacheDir, String title, String strUrl) throws IOException {
Path cacheFile = cacheDir.resolve(title);
Path cacheFileDate = cacheDir.resolve(title + "_date");
URL url = new URL(strUrl);
URLConnection connection = url.openConnection();
if (Files.exists(cacheFile) && Files.exists(cacheFileDate)) {
String dateValue = Files.readAllLines(cacheFileDate).get(0);
connection.addRequestProperty("If-Modified-Since", dateValue);
String httpStatus = connection.getHeaderField(0);
if (httpStatus.indexOf(" 304 ") == -1) { // assuming that we get status 200 here instead
writeFiles(connection, cacheFile, cacheFileDate);
} else { // else not modified, so do not do anything, we return the cache file
System.out.println("Using cached file");
}
} else {
writeFiles(connection, cacheFile, cacheFileDate);
}
return cacheFile;
}
private void writeFiles(URLConnection connection, Path cacheFile, Path cacheFileDate) throws IOException {
System.out.println("Creating cache entry");
try (InputStream inputStream = connection.getInputStream()) {
Files.copy(inputStream, cacheFile, StandardCopyOption.REPLACE_EXISTING);
}
String lastModified = connection.getHeaderField("Last-Modified");
Files.write(cacheFileDate, lastModified.getBytes());
System.out.println(connection.getHeaderFields());
}

How can I save a jar file from a web server locally in a command-line program that exits and ONLY update that jar file when it has been changed on the server?
With JWS. It has an API so you can control it from your existing code. It already has versioning and caching, and comes with a JAR-serving servlet.

I have assumed that a .md5 file will be available both locally and at the web server. Same logic will apply if you wanted this to be a version control file.
The urls given in the following code need to updated according to your web server location and app context. Here is how your command line code would go
public class Main {
public static void main(String[] args) {
String jarPath = "/Users/nrj/Downloads/local/";
String jarfile = "apache-storm-0.9.3.tar.gz";
String md5File = jarfile + ".md5";
try {
// Update the URL to your real server location and application
// context
URL url = new URL(
"http://localhost:8090/JarServer/myjar?hash=md5&file="
+ URLEncoder.encode(jarfile, "UTF-8"));
BufferedReader in = new BufferedReader(new InputStreamReader(
url.openStream()));
// get the md5 value from server
String servermd5 = in.readLine();
in.close();
// Read the local md5 file
in = new BufferedReader(new FileReader(jarPath + md5File));
String localmd5 = in.readLine();
in.close();
// compare
if (null != servermd5 && null != localmd5
&& localmd5.trim().equals(servermd5.trim())) {
// TODO - Execute the existing jar
} else {
// Rename the old jar
if (!(new File(jarPath + jarfile).renameTo((new File(jarPath + jarfile
+ String.valueOf(System.currentTimeMillis())))))) {
System.err
.println("Unable to rename old jar file.. please check write access");
}
// Download the new jar
System.out
.println("New jar file found...downloading from server");
url = new URL(
"http://localhost:8090/JarServer/myjar?download=1&file="
+ URLEncoder.encode(jarfile, "UTF-8"));
// Code to download
byte[] buf;
int byteRead = 0;
BufferedOutputStream outStream = new BufferedOutputStream(
new FileOutputStream(jarPath + jarfile));
InputStream is = url.openConnection().getInputStream();
buf = new byte[10240];
while ((byteRead = is.read(buf)) != -1) {
outStream.write(buf, 0, byteRead);
}
outStream.close();
System.out.println("Downloaded Successfully.");
// Now update the md5 file with the new md5
BufferedWriter bw = new BufferedWriter(new FileWriter(md5File));
bw.write(servermd5);
bw.close();
// TODO - Execute the jar, its saved in the same path
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
And just in case you had control over the servlet code as well, this is how the servlet code goes:-
#WebServlet(name = "jarervlet", urlPatterns = { "/myjar" })
public class JarServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
// Remember to have a '/' at the end, otherwise code will fail
private static final String PATH_TO_FILES = "/Users/nrj/Downloads/";
#Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String fileName = req.getParameter("file");
if (null != fileName) {
fileName = URLDecoder.decode(fileName, "UTF-8");
}
String hash = req.getParameter("hash");
if (null != hash && hash.equalsIgnoreCase("md5")) {
resp.getWriter().write(readMd5Hash(fileName));
return;
}
String download = req.getParameter("download");
if (null != download) {
InputStream fis = new FileInputStream(PATH_TO_FILES + fileName);
String mimeType = getServletContext().getMimeType(
PATH_TO_FILES + fileName);
resp.setContentType(mimeType != null ? mimeType
: "application/octet-stream");
resp.setContentLength((int) new File(PATH_TO_FILES + fileName)
.length());
resp.setHeader("Content-Disposition", "attachment; filename=\""
+ fileName + "\"");
ServletOutputStream os = resp.getOutputStream();
byte[] bufferData = new byte[10240];
int read = 0;
while ((read = fis.read(bufferData)) != -1) {
os.write(bufferData, 0, read);
}
os.close();
fis.close();
// Download finished
}
}
private String readMd5Hash(String fileName) {
// We are assuming there is a .md5 file present for each file
// so we read the hash file to return hash
try (BufferedReader br = new BufferedReader(new FileReader(
PATH_TO_FILES + fileName + ".md5"))) {
return br.readLine();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

I can share experience of solving the same problem in our team. We have several desktop product written in java which are updated regularly.
Couple years ago we had separate update server for every product and following process of update: Client application has an updater wrapper that starts before main logic, and stored in a udpater.jar. Before start, application send request to update server with MD5-hash of application.jar file. Server compares received hash with the one that it has, and send new jar file to updater if hashes are different.
But after many cases, where we confused which build is now in production, and update-server failures we switched to continuous integration practice with TeamCity on top of it.
Every commit done by developer is now tracked by build server. After compilation and test passing build server assigns build number to application and shares app distribution in local network.
Update server now is a simple web server with special structure of static files:
$WEB_SERVER_HOME/
application-builds/
987/
988/
989/
libs/
app.jar
...
changes.txt <- files, that changed from last build
lastversion.txt <- last build number
Updater on client side requests lastversion.txt via HttpClient, retrieves last build number and compares it with client build number stored in manifest.mf.
If update is required, updater harvests all changes made since last update iterating over application-builds/$BUILD_NUM/changes.txt files. After that, updater downloads harvested list of files. There could be jar-files, config files, additional resources etc.
This scheme is seems complex for client updater, but in practice it is very clear and robust.
There is also a bash script that composes structure of files on updater server. Script request TeamCity every minute to get new builds and calculates diff between builds. We also upgrading now this solution to integrate with project management system (Redmine, Youtrack or Jira). The aim is to able product manager to mark build that are approved to be updated.
UPDATE.
I've moved our updater to github, check here: github.com/ancalled/simple-updater
Project contains updater-client on Java, server-side bash scripts (retrieves updates from build-server) and sample application to test updates on it.

jcifs.smb.SmbException: Access is Denied. exception for smb directories

In the below code statement:
SmbFileInputStream din==new SmbFileInputStream(src);
I am trying to create a SmbFileInputStream object. This will works fine if SmbFile 'src' is a file, but if 'src' is a smb Directory then it throws exception:
jcifs.smb.SmbException: Access is Denied.
at jcifs.smb.SmbTransport.checkStatus(SmbTransport.java:622)
at jcifs.smb.SmbTransport.send(SmbTransport.java:722)
at jcifs.smb.SmbSession.send(SmbSession.java:262)
at jcifs.smb.SmbTree.send(SmbTree.java:119)
at jcifs.smb.SmbFile.send(SmbFile.java:785)
at jcifs.smb.SmbFile.open0(SmbFile.java:1009)
at jcifs.smb.SmbFile.open(SmbFile.java:1026)
at jcifs.smb.SmbFileInputStream.<init>(SmbFileInputStream.java:73)
at jcifs.smb.SmbFileInputStream.<init>(SmbFileInputStream.java:65)
at testhelp.main(testhelp.java:25)
What is wrong with this code? or where am I going wrong?
Hi please check this code:
case DOWNLOAD2:
/*This code snippet is used to download a file/folder from smb nETWORK to android sd card.
when I run this code its throwing some exception. It have commented where ever necessary. rest of the code is self
explanatory. So please go through the code and please tell why this exception is thrown.
IF POSSIBLE PLEASE ADD A PROGRESS BAR WHICH SHOULD HELP USER SAYING SOME WORK IS GOING ON.
I have tried including a progress bar, but its not working. I ve read some materials related to this,
but every thing makes use threads. I am not that good at threads. So is it possible to include a progess bar,
without using threads?If possible please help me to do it.
And this code is working file for smb files, I dont know why its throwing exception in case of directories.
Please see why this is throwing exception..
So please see that the modified code contains:
a)no exceptions
b)a progress bar(more specifically a horizontal bar)*/
/*exception thrown:
jcifs.smb.SmbException: Access is Denied.
at jcifs.smb.SmbTransport.checkStatus(SmbTransport.java:622)
at jcifs.smb.SmbTransport.send(SmbTransport.java:722)
at jcifs.smb.SmbSession.send(SmbSession.java:262)
at jcifs.smb.SmbTree.send(SmbTree.java:119)
at jcifs.smb.SmbFile.send(SmbFile.java:785)
at jcifs.smb.SmbFile.open0(SmbFile.java:1009)
at jcifs.smb.SmbFile.open(SmbFile.java:1026)
at jcifs.smb.SmbFileInputStream.<init>(SmbFileInputStream.java:73)
at jcifs.smb.SmbFileInputStream.<init>(SmbFileInputStream.java:65)
at testhelp.main(testhelp.java:25)*/
StatFs statFs = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());
//if sd card is mounted then only this operation occur:
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
//object.getCount() gets the number of objects in list view
for(int i=0;i<object.getCount();i++)
{
//for each object in list view, if it is checked:
if(object.getter(i)==true)
{
SmbFileInputStream din=null;
FileOutputStream dout=null;
try
{
//I have used a hash table, which maps list view name with smb object
SmbFile src=map.get(object.getItem(i));
long blockSize = statFs.getBlockSize();
long freeSize = statFs.getFreeBlocks()*blockSize;
long diff=freeSize-src.length();
boolean can=false;
if(!(diff<0))
{
can=true;
}
if(!src.isHidden() && can)
{
try
{
if(src.isFile())
{
din=new SmbFileInputStream(src);
dout=new FileOutputStream(Environment.getExternalStorageDirectory()+"/"+src.getName());
}
else
{
din=new SmbFileInputStream(src);
File outputFile = new File(Environment.getExternalStorageDirectory()+"/"+src.getName()); // ADDED
outputFile.mkdirs(); // ADDED
dout=new FileOutputStream(outputFile); // CHANGED
}
int c;
while((c=din.read())!=-1)
{
dout.write(c);
}
}
finally
{
if (din != null)
{
din.close();
}
if (dout != null)
{
dout.close();
}
}
}
else
{
Toast.makeText(this,src.getName()+" cannot be downloaded",Toast.LENGTH_LONG).show();
}
}
catch(IOException e)
{
Toast.makeText(this,"DOWNLOAD FAILED--IO EXCEPTION\n"+e,Toast.LENGTH_LONG).show();
}
}
}
}
else
{
Toast.makeText(this,"DOWNLOAD FAILED--NO SD CARD FOUND",Toast.LENGTH_LONG).show();
}
return true;

You can't create an SmbFileInputStream for a directory, because you can't read/write directly to the directory object. A directory doesn't have any content, at least not in the same way that a file has content.
If you're trying to read the contents of a directory, you should probably be using SmbFile instead (for example, use the listFiles() method). The SmbFileInputStream object is only for reading information from a file.
To write a file to a directory, do this...
File file = new File("/mnt/sdcard/filename.txt");
file.mkdirs(); // this creates all the directories that are missing
FileOutputStream os = new FileOutputStream (file);
// now write the file data
os.write(...);
In your code, change the following few lines...
try
{
din=new SmbFileInputStream(src);
dout=new FileOutputStream(Environment.getExternalStorageDirectory()+"/"+src.getName());
int c;
while((c=din.read())!=-1)
To this...
try
{
din=new SmbFileInputStream(src);
File outputFile = new File(Environment.getExternalStorageDirectory()+"/"+src.getName()); // ADDED
outputFile.mkdirs(); // ADDED
dout=new FileOutputStream(outputFile); // CHANGED
int c;
while((c=din.read())!=-1)
Also change the following...
if(src.isFile()){
din=new SmbFileInputStream(src);
//dout=new FileOutputStream(Environment.getExternalStorageDirectory()+"/"+src.getName());// REMOVE THIS LINE
File outputFile = new File(Environment.getExternalStorageDirectory()+"/"+src.getName()); // ADDED
outputFile.mkdirs(); // ADDED
dout=new FileOutputStream(outputFile); // ADDED
}
else {
//din=new SmbFileInputStream(src); // REMOVE THIS LINE
File outputFile = new File(Environment.getExternalStorageDirectory()+"/"+src.getName());
outputFile.mkdirs();
//dout=new FileOutputStream(outputFile); // REMOVE THIS LINE
}