Question at the bottom
I'm using netty to transfer a file to another server.
I limit my file-chunks to 1024*64 bytes (64KB) because of the WebSocket protocol. The following method is a local example what will happen to the file:
public static void rechunck(File file1, File file2) {
FileInputStream is = null;
FileOutputStream os = null;
try {
byte[] buf = new byte[1024*64];
is = new FileInputStream(file1);
os = new FileOutputStream(file2);
while(is.read(buf) > 0) {
os.write(buf);
}
} catch (IOException e) {
Controller.handleException(Thread.currentThread(), e);
} finally {
try {
if(is != null && os != null) {
is.close();
os.close();
}
} catch (IOException e) {
Controller.handleException(Thread.currentThread(), e);
}
}
}
The file is loaded by the InputStream into a ByteBuffer and directly written to the OutputStream.
The content of the file cannot change while this process.
To get the md5-hashes of the file I've wrote the following method:
public static String checksum(File file) {
InputStream is = null;
try {
is = new FileInputStream(file);
MessageDigest digest = MessageDigest.getInstance("MD5");
byte[] buffer = new byte[8192];
int read = 0;
while((read = is.read(buffer)) > 0) {
digest.update(buffer, 0, read);
}
return new BigInteger(1, digest.digest()).toString(16);
} catch(IOException | NoSuchAlgorithmException e) {
Controller.handleException(Thread.currentThread(), e);
} finally {
try {
is.close();
} catch(IOException e) {
Controller.handleException(Thread.currentThread(), e);
}
}
return null;
}
So: just in theory it should return the same hash, shouldn't it? The problem is that it returns two different hashes that do not differ with every run.. file size stays the same and the content either.
When I run the method once for in: file-1, out: file-2 and again with in: file-2 and out: file-3 the hashes of file-2 and file-3 are the same! This means the method will properly change the file every time the same way.
1. 58a4a9fbe349a9e0af172f9cf3e6050a
2. 7b3f343fa1b8c4e1160add4c48322373
3. 7b3f343fa1b8c4e1160add4c48322373
Here is a little test that compares all buffers if they are equivalent. Test is positive. So there aren't any differences.
File file1 = new File("controller/templates/Example.zip");
File file2 = new File("controller/templates2/Example.zip");
try {
byte[] buf1 = new byte[1024*64];
byte[] buf2 = new byte[1024*64];
FileInputStream is1 = new FileInputStream(file1);
FileInputStream is2 = new FileInputStream(file2);
boolean run = true;
while(run) {
int read1 = is1.read(buf1), read2 = is2.read(buf2);
String result1 = Arrays.toString(buf1), result2 = Arrays.toString(buf2);
boolean test = result1.equals(result2);
System.out.println("1: " + result1);
System.out.println("2: " + result2);
System.out.println("--- TEST RESULT: " + test + " ----------------------------------------------------");
if(!(read1 > 0 && read2 > 0) || !test) run = false;
}
} catch (IOException e) {
e.printStackTrace();
}
Question: Can you help me chunking the file without changing the hash?
while(is.read(buf) > 0) {
os.write(buf);
}
The read() method with the array argument will return the number of files read from the stream. When the file doesn't end exactly as a multiple of the byte array length, this return value will be smaller than the byte array length because you reached the file end.
However your os.write(buf); call will write the whole byte array to the stream, including the remaining bytes after the file end. This means the written file gets bigger in the end, therefore the hash changed.
Interestingly you didn't make the mistake when you updated the message digest:
while((read = is.read(buffer)) > 0) {
digest.update(buffer, 0, read);
}
You just have to do the same when you "rechunk" your files.
Your rechunk method has a bug in it. Since you have a fixed buffer in there, your file is split into ByteArray-parts. but the last part of the file can be smaller than the buffer, which is why you write too many bytes in the new file. and that's why you do not have the same checksum anymore. the error can be fixed like this:
public static void rechunck(File file1, File file2) {
FileInputStream is = null;
FileOutputStream os = null;
try {
byte[] buf = new byte[1024*64];
is = new FileInputStream(file1);
os = new FileOutputStream(file2);
int length;
while((length = is.read(buf)) > 0) {
os.write(buf, 0, length);
}
} catch (IOException e) {
Controller.handleException(Thread.currentThread(), e);
} finally {
try {
if(is != null)
is.close();
if(os != null)
os.close();
} catch (IOException e) {
Controller.handleException(Thread.currentThread(), e);
}
}
}
Due to the length variable, the write method knows that until byte x of the byte array, only the file is off, then there are still old bytes in it that no longer belong to the file.
Related
I have a log analyzing tool that needs to grab *.gz files from Linux servers and unzip them on both Linux and Windows clients. I am getting "Unexpected end of ZLIB input stream" in many instances, which I assume is a difference in detail in the files on Linux and Windows.
Below is my function. It's pretty basic. How do I improved it to prevent the EOF error?
The "in" symbol is a FileInputStream that is created when constructing the class that this function is part of.
public void unzip(File fileTo) throws IOException {
OutputStream out = new FileOutputStream(fileTo);
LOGGER.info("Setting up the file for outputstream : "+fileTo);
try {
in = new GZIPInputStream(in);
byte[] buffer = new byte[65536];
int noRead;
while ((noRead = in.read(buffer)) != -1) {
out.write(buffer, 0, noRead);
}
} finally {
try { out.close(); } catch (Exception e) {}
}
}
I changed from the above to this and now it works. It seems that it was trying to load the output stream before it was done loading the input stream.
public void unzip(File fileTo, String f) throws IOException,
EOFException, InterruptedException {
LOGGER.info("Setting up the file for outputstream : "+fileTo);
GZIPInputStream cIn = new GZIPInputStream(new FileInputStream(f));
OutputStream out = new FileOutputStream(fileTo);
fileTo.setReadable(true, false);
fileTo.setWritable(true, false);
byte[] buffer = new byte[65536];
int noRead;
for (int i = 10; i > 0 && cIn.available() == 1; i--) {
Thread.sleep(1000);
}
try {
while ((noRead = cIn.read(buffer)) != -1) {
out.write(buffer, 0, noRead);
}
} finally {
try { out.close();cIn.close();in.close(); } catch (Exception e) {}
}
}
I am learning sockets and now I want to write file transfer program. I have server part and client part. Server part contains 2 ports: 5000 (commands) and 5001 (files). Now I want to send a file via socket and when I did something is wrong because only 425B of data is sending.
Here is client send method:
private void sendFile(Socket socket) {
File file2 = new File("C:\\Users\\barte\\Desktop\\dos.png");
byte[] bytes = new byte[16 * 1024];
System.out.println(file2.exists());
try (InputStream inputStream = new FileInputStream(file2);
OutputStream outputStream = socket.getOutputStream();
OutputStream secondOutput = new FileOutputStream("C:\\Users\\barte\\Desktop\\received\\dos.png")) {
int count;
while ((count = inputStream.read(bytes)) > 0) {
outputStream.write(bytes, 0, count);
secondOutput.write(bytes, 0, count);
}
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
As you can see (image below) I am writing this file also locally and everything is ok, all of 73KB of data is writed.
Now, on server side I am trying to receive this file:
case SEND: {
new Thread(() -> {
printWriter.println("Server is receiving files right now...");
try (ServerSocket serverSocket = new ServerSocket(5001)) {
while (true) {
new FilesTransfer(serverSocket.accept()).start();
}
} catch (IOException e) {
e.printStackTrace();
}
}).start();
break;
}
And inside FilesTransfer run method:
#Override
public void run() {
System.out.println("Hello there");
try {
InputStream inputStream = inSocket.getInputStream();
OutputStream outputStream = new FileOutputStream("C:\\Users\\barte\\Desktop\\received\\file");
byte[] bytes = new byte[16 * 1024];
int count;
while ((count = inputStream.read()) > 0) {
outputStream.write(bytes, 0, count);
}
outputStream.close();
inputStream.close();
inSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Where is a bug? Why only empty bytes are sending when locally everything it's fine?
The problem is:
while ((count = inputStream.read()) > 0) {
Your code uses InputStream.read(), which reads individual bytes (or -1 when end-of-stream). Right now, you are reading individual bytes, interpreting that as a length, and then writing that number of 0x00 bytes from bytes to the file. This stops when you read a 0x00 byte from the stream.
You need to change this to use InputStream.read(byte[]):
while ((count = inputStream.read(bytes)) != -1) {
That is, you need to pass bytes in, and check for the result being unequal to -1, not if it is greater than zero (0), although read(byte[]) will only return 0 if the passed in byte array has length zero, so that is not a real concern.
You could do it in this way:
#Override
public void run() {
System.out.println("Hello there");
try {
InputStream inputStream = inSocket.getInputStream();
OutputStream outputStream = new FileOutputStream("C:\\Users\\barte\\Desktop\\received\\file");
byte[] bytes = new byte[16 * 1024];
int byteRead= 1;
while (byteRead > -1) {
byteRead= inputStream.read();
outputStream.write(byteRead);
}
outputStream.close();
inputStream.close();
inSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Actually END OF FILE or EOF means -1 and you did > 0 so 0 was taken and it stopped the connection saving the file.
I also recommend to write a logic to transfer the filename as a command to the server so that the file is saved with the correct name and extension!
This question already has answers here:
Java multiple file transfer over socket
(3 answers)
Closed 6 years ago.
I am first transferring a file from a client to my master, the stores the byte array and then sends to the slave. Where the slave stores the byte array. But when The file is sent properly from client to master but when I send the byte array to the slave it to the slave the read method in input stream constantly reads 0.
// This method writes the file to the master
public void writeFile(File file) {
try {
this.write(String.valueOf(file.length()));
byte[] bytearray = new byte[(int) file.length()];
FileInputStream fin = new FileInputStream(file);
BufferedInputStream bin = new BufferedInputStream(fin);
bin.read(bytearray, 0, bytearray.length);
BufferedOutputStream bos;
OutputStream os = socket.getOutputStream();
bos= new BufferedOutputStream(os);
bos.write(bytearray, 0, bytearray.length);
bos.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
//This method reads the file into the master as a byte array and the byte array from the master into slave
public byte[] readFile() {
byte[] bytearray = null;
try {
int currentTot = 0;
int filesize = Integer.parseInt(this.read());
System.out.println(filesize);
bytearray = new byte[filesize];
InputStream is = socket.getInputStream();
int bytesRead;
bytesRead = is.read(bytearray, 0, bytearray.length);
currentTot = bytesRead;
int count = 0;
do {
bytesRead = is.read(bytearray, currentTot, (bytearray.length - currentTot));
if (bytesRead > 0) {
currentTot += bytesRead;
count = 0;
} else {
count++;
System.out.println("count " + count);
}
} while (bytesRead > -1);
System.out.println(currentTot);
// bos.write(bytearray, 0, currentTot);
// bos.flush();
// bos.close();
} catch (IOException e) {
e.printStackTrace();
}
return bytearray;
}
//This method writes from the master to the slave
public void writeByte(byte[] m) {
this.write(String.valueOf(m.length));
System.out.println("File side inside sender" + m.length);
// byte[] bytearray = m;
OutputStream os;
try {
os = socket.getOutputStream();
os.write(m, 0, m.length);
os.flush();
//os.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Interestingly if I close my output stream after I send my byte array from my master it works well. But I cannot close stream because the slave needs to communicate with the master further. Thanks in advance.
public void write(String output) {
if (pw == null)
this.openWriter();
pw.println(output);
}
public String read() {
try {
if (br == null) {
if (this.socket != null)
br = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
}
return br.readLine();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
You're misreading the file length in the receiver. You are getting zero, so you're constructing a zero length byte array, so read() returns zero.
You need to send the length via DataOutputStream.writeLong() and read it via DataInputStream.readLong(). And then your sending and receiving code is all wrong as well. See my answer here for complete code.
I am reading a .jpg file over InputStream using this code but I am receiving NULNUL...n stream after some text. Ii am reading this file link to file and link of file that I received , link is Written File link.
while ((ret = input.read(imageCharArray)) != -1) {
packet.append(new String(imageCharArray, 0, ret));
totRead += ret;
imageCharArray = new char[4096];
}
file = new File(
Environment.getExternalStorageDirectory()
+ "/FileName_/"
+ m_httpParser.filename + ".jpg");
PrintWriter printWriter = new PrintWriter(file);
// outputStream = new FileOutputStream(file); //also Used FileoutputStream for writting
// outputStream.write(packet.toString().getBytes());//
// ,
printWriter.write(packet.toString());
// outputStream.close();
printWriter.close();
}
I have also tried FileoutputStream but hardlucj for this too as commented in my code.
Edit
I have used this also. I have a content length field upto which i am reading and writing
byte[] bytes = new byte[1024];
int totalReadLength = 0;
// read untill we have bytes
while ((read = inputStream.read(bytes)) != -1
&& contentLength >= (totalReadLength)) {
outputStream.write(bytes, 0, read);
totalReadLength += read;
System.out.println(" read size ======= "
+ read + " totalReadLength = "
+ totalReadLength);
}
String is not a container for binary data, and PrintWriter isn't a way to write it. Get rid of all, all, the conversions between bytes and String and vice versa, and just transfer the bytes with input and output streams:
while ((count = in.read(buffer)) > 0)
{
out.write(buffer, 0, count);
}
If you need to constrain the number of bytes read from the input, you have to do that before calling read(), and you also have to constrain the read() correctly:
while (total < length && (count = in.read(buffer, 0, length-total > buffer.length ? buffer.length: (int)(length-total))) > 0)
{
total += count;
out.write(buffer, 0, count);
}
I tested it in my Nexus4 and it's working for me. Here is the snippet of code what I tried :
public void saveImage(String urlPath)throws Exception{
String fileName = "kumar.jpg";
File folder = new File("/sdcard/MyImages/");
// have the object build the directory structure, if needed.
folder.mkdirs();
final File output = new File(folder,
fileName);
if (output.exists()) {
output.delete();
}
InputStream stream = null;
FileOutputStream fos = null;
try {
URL url = new URL(urlPath);
stream = url.openConnection().getInputStream();
// InputStreamReader reader = new InputStreamReader(stream);
DataInputStream dis = new DataInputStream(url.openConnection().getInputStream());
byte[] fileData = new byte[url.openConnection().getContentLength()];
for (int x = 0; x < fileData.length; x++) { // fill byte array with bytes from the data input stream
fileData[x] = dis.readByte();
}
dis.close();
fos = new FileOutputStream(output.getPath());
fos.write(fileData);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Just Call the above function in a background thread and pass your url. It'll work for sure. Let me know if it helps.
You can check below code.
destinationFile = new File(
Environment.getExternalStorageDirectory()
+ "/FileName_/"
+ m_httpParser.filename + ".jpg");
BufferedOutputStream buffer = new BufferedOutputStream(new FileOutputStream(destinationFile));
byte byt[] = new byte[1024];
int i;
for (long l = 0L; (i = input.read(byt)) != -1; l += i ) {
buffer.write(byt, 0, i);
}
buffer.close();
I have this code to read bytes to another file.
But I'm not able to concatenate two mp3 files into one.
Am I missing something?
public static void main(String[] args) {
String strFileName = ("D:/Music/Assb/Love.mp3");
BufferedOutputStream bos = null;
try
{
//create an object of FileOutputStream
FileOutputStream fos = new FileOutputStream(new File(strFileName));
//create an object of BufferedOutputStream
bos = new BufferedOutputStream(fos);
String str = "D:/Music/Assembled/Heart001.mp3"
+ "D:/Music/Assembled/Heart002.mp3";
/*
* To write byte array to file use,
* public void write(byte[] b) method of BufferedOutputStream
* class.
*/
System.out.println("Writing byte array to file");
bos.write(str.getBytes());
System.out.println("File written");
It`s suck. Mp3 file starts with headers. For correct merging you have to skip first 32 bytes. Try this.
try {
FileInputStream fistream1 = new FileInputStream(_file_name);
File f = new File(new File(_file_name).getParent()+"/final.mp3");
if(!f.exists())
{
f.createNewFile();
}
FileOutputStream sistream = new FileOutputStream((new File(_file_name)).getParent()+"/final.mp3");
int temp;
int size = 0;
temp = fistream1.read();
while( temp != -1)
{
sistream.write(temp);
temp = fistream1.read();
};
fistream1.close();
FileInputStream fistream2 = new FileInputStream(temp_file);
fistream2.read(new byte[32],0,32);
temp = fistream2.read();
while( temp != -1)
{
sistream.write(temp);
temp = fistream2.read();
};
fistream2.close();
sistream.close();
} catch (IOException e) {
e.printStackTrace();
}
You need to do this in two steps
String str = "D:/Music/Assembled/Heart001.mp3";
>>> ADD code to open the file given by str <<<<
bos.write(strFile.getBytes());
>>> Add code to close the file
str = "D:/Music/Assembled/Heart002.mp3";
>>> ADD code to open the file given by str <<<<
bos.write(strFile.getBytes());
>>> Add code to close the file
And as you can see you need code to open the mp3 file to read it
What Are You Trying For...Actually..if You Want To Read 2 Files to Byte Stream the dont String str = "D:/Music/Assembled/Heart001.mp3"
+ "D:/Music/Assembled/Heart002.mp3";
make str1=D:/Music/Assembled/Heart001.mp3 and str2=D:/Music/Assembled/Heart002.mp3 and read str1,str2 seperately through bufferedoutputsream
This code will work well and merge audio of similar type with in seconds...
try {
InputStream in = new FileInputStream("C:\\a.mp3");//firstmp3
byte[] buffer = new byte[1 << 20]; // loads 1 MB of the file
OutputStream os = new FileOutputStream(new File("C:\\output.mp3", true);//output mp3
int count;
while ((count = in.read(buffer)) != -1) {
os.write(buffer, 0, count);
os.flush();
}
in.close();
in = new FileInputStream("C:\\b.mp3");//second mp3
while ((count = in.read(buffer)) != -1) {
os.write(buffer, 0, count);
os.flush();
}
in.close();
os.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}