Develop Reference

Address already in use (bind failed)

I'm using these two java sources to exchange a file between 2 PC(linux and mac).
The problem is showed only on Linux.
I'm using these 2 codes in a thread where i recall more times.
But i have this error: Address already in use (bind failed).
I have searched on the web and on this forum that the problem is the TCP connection still active, so there is a function of the class Server Socket called setReuseAddress(true) which allows me to reuse the address. I call this function after the instantiation of ServerSocket but the problems persists.
How can i resolve this problem?
[EDIT]
Server
{
final int SOCKET_PORT = 13267;
final String FILE_TO_SEND = "/Users/jo/Desktop/cryptedSymmetric.key";
boolean flag = true;
FileInputStream fis = null;
BufferedInputStream bis = null;
OutputStream os = null;
ServerSocket servsock = null;
Socket sock = null;
try {
servsock = new ServerSocket(); // create unbound ServerSocket
servsock.setReuseAddress(true);
servsock.bind(new InetSocketAddress(SOCKET_PORT));
// while (flag) {
System.out.println("SO_REUSEADDRESS is enabled: " + servsock.getReuseAddress());
System.out.println("Waiting client B...");
try {
sock = servsock.accept();
System.out.println("Connection : " + sock);
// send file
File myFile = new File(FILE_TO_SEND);
byte[] mybytearray = new byte[(int) myFile.length()];
fis = new FileInputStream(myFile);
bis = new BufferedInputStream(fis);
bis.read(mybytearray, 0, mybytearray.length);
os = sock.getOutputStream();
System.out.println("Invio del file " + FILE_TO_SEND + "(" + mybytearray.length + " bytes)");
os.write(mybytearray, 0, mybytearray.length);
os.flush();
System.out.println("Done.");
flag = false;
} finally {
if (bis != null)
bis.close();
if (os != null)
os.close();
if (sock != null)
sock.close();
}
// }
} finally {
if (servsock != null)
servsock.close();
return flag;
}
}
EDIT Client
{
int SOCKET_PORT = 0;
SOCKET_PORT = 13267;
// final String SERVER = "192.168.1.2";
final String FILE_TO_RECEIVED = "/Users/jo/Desktop/publicB.key";
final int FILE_SIZE = 6022386;
boolean flag = true;
int bytesRead;
int current = 0;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
Socket sock = null;
try {
sock = new Socket(address.getHostAddress(), SOCKET_PORT);
System.out.println("Connessione...");
// receive file
byte[] mybytearray = new byte[FILE_SIZE];
InputStream is = sock.getInputStream();
fos = new FileOutputStream(FILE_TO_RECEIVED);
bos = new BufferedOutputStream(fos);
// bytesRead = is.read(mybytearray, 0, mybytearray.length);
// current = bytesRead;
int count;
while ((count = is.read(mybytearray)) > 0) {
bos.write(mybytearray, 0, count);
}
bos.flush();
System.out.println("File " + FILE_TO_RECEIVED + " scaricato (" + current + " bytes letti)");
flag = false;
} finally {
if (fos != null)
fos.close();
if (bos != null)
bos.close();
if (sock != null)
sock.close();
return flag;
}
}

I call this function after the instantiation of ServerSocket but the problems persists.
That's because you called it too late. You should have observed that the exception was thrown before the call. You need to separate creation from binding:
servsock = new ServerSocket(); // create unbound ServerSocket
servsock.setReuseAddress(true);
servsock.bind(new InetSocketAddress(SOCKET_PORT));
NB your copy code should be the same at both ends, and not like either version you've used, which exhibit various problems and fallacies:
while ((count = in.read(buffer)) > 0)
{
out.write(buffer, 0, count);
}

moving file from source folder to desktop

I am trying to move the file from the source file to automatically be saved to desktop. Essentially this is an incoming file and I want it where its visible to the user which is his/her desktop I thought I was on the right track but this code doesn't work and previous modifications does not work either can someone point me in the right direction?
System.out.println("Waiting For File......");
int filesize = 6022386;
byte[] mybytearray = new byte[filesize];
InputStream is;
is = connection_download.getInputStream();
FileOutputStream fos;
// obtain header (fileName)
DataInputStream clientData = new DataInputStream(is);
String fileName = clientData.readUTF();
OutputStream output = new FileOutputStream(fileName);
System.out.println(fileName);
fos = new FileOutputStream(fileName);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = is.read(mybytearray, 0, mybytearray.length);
current = bytesRead;
do {
bytesRead = is.read(mybytearray, current, (mybytearray.length - current));
if (bytesRead >= 0) {
current += bytesRead;
}
} while (bytesRead > -1);
bos.write(mybytearray, 0, current);
bos.flush();
System.out.println(fileName.length());
long end = System.currentTimeMillis();
System.out.println("DONE");
bos.close();
// complete file
complete = new File(fileName);
if (isMacOs == true) {
downloadMac(complete);
} else if (isWindowsOS == true) {
downloadWindows(complete);
}
} catch (IOException ex) {
Logger.getLogger(downloadFile.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
public void downloadMac(File complete) {
JOptionPane.showMessageDialog(null, "Your Files Will be Saved To Your Desktop");
String OS_Path = System.getProperty("user.home");
String savedLocation = OS_Path + "/Desktop/" + complete;
File downloadedLocation = new File(savedLocation);
System.out.println(downloadedLocation);
}

Having trouble sending file from server to another Client (Java)

I'm having some difficulties trying to send file from server to the other client.
Let's say I have two clients connected to the server.
Now Server successfully sent the file to the 1st client But then when the server tries to send to the second client the client does not receive it.
Here's some code to begin with :
Server:
public synchronized void sendToAllClients() {
for (Socket z : clientSockets) {
if (z != null) {
System.out.println("TEST");
PrintWriter print = null;
try {
File myFile = new File(FILE PATH);
byte[] mybytearray = new byte[(int) myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
DataInputStream dis = new DataInputStream(bis);
dis.readFully(mybytearray, 0, mybytearray.length);
OutputStream os = z.getOutputStream();
DataOutputStream dos = new DataOutputStream(os);
dos.writeLong(mybytearray.length);
dos.write(mybytearray, 0, mybytearray.length);
dos.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
Client:
public static void receiveFile(String fileName) {
try {
int bytesRead;
InputStream in = sock.getInputStream();
clientData = new DataInputStream(in);
OutputStream output = new FileOutputStream(
(FILEPATH + FILENAME);
long size = clientData.readLong();
byte[] buffer = new byte[1024];
while (size > 0
&& (bytesRead = clientData.read(buffer, 0,
(int) Math.min(buffer.length, size))) != -1) {
output.write(buffer, 0, bytesRead);
size -= bytesRead;
}
output.flush();
} catch (IOException ex) {
}
}

Data loss while sending image over socket from android client to Java server

I'm trying to send my image from android client to Java server. Size of image that i'm sending is about 99kb, but server always reads a few kb less, sometimes 98, sometimes 96 and so on. I'd like to know why that data is lost and how can I send image in a proper way. Please help :)
Code:
Client(sending image):
public void sendImage(File file){
try {
out = new PrintWriter(socket.getOutputStream(),true);
out.println("Image");
out.println(file.length());
byte[] byteArray = new byte[(int) file.length()];
FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(byteArray,0,byteArray.length);
OutputStream os = socket.getOutputStream();
FilterOutputStream bos = new FilterOutputStream(os);
bos.write(byteArray,0,byteArray.length);
bos.flush();
os.close();
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Server(receiving image):
if(input.equals("Image")){
input = in.readLine();
int fileSize = Integer.parseInt(input);
System.out.println("FILESIZE:" +fileSize);
byte[] byteArray = new byte[fileSize];
FileOutputStream fileOutputStream =
new FileOutputStream("filename.jpg");
BufferedOutputStream bos =
new BufferedOutputStream(fileOutputStream);
BufferedInputStream bis = new BufferedInputStream(in_);
int bytesRead = bis.read(byteArray, 0, byteArray.length);
int current = bytesRead;
do {
bytesRead = bis.read(byteArray, current,
(byteArray.length - current));
if (bytesRead >= 0) {
current += bytesRead;
System.out.println(current);
}
} while (bytesRead != -1);
bos.write(byteArray, 0, current);
bos.flush();
bos.close();
}
EDIT
Problem solved, working code is as follows:
Client side:
public void sendImage(File file){
try {
DataOutputStream out = new DataOutputStream(
socket.getOutputStream());
out.writeChar('I');
DataInputStream dis = new DataInputStream(new FileInputStream(file));
ByteArrayOutputStream ao = new ByteArrayOutputStream();
int read = 0;
byte[] buf = new byte[1024];
while ((read = dis.read(buf)) > -1) {
ao.write(buf, 0, read);
}
out.writeLong(ao.size());
out.write(ao.toByteArray());
out.flush();
out.close();
dis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Server side:
if(input =='I'){
DataInputStream dis = new DataInputStream(clientSocket.getInputStream());
long length = dis.readLong();
File to = new File("filename.jpg");
DataOutputStream dos = new DataOutputStream(
new FileOutputStream(to));
byte[] buffer = new byte[1024];
int len, current = 0;
System.out.println(length);
while ( current != length) {
len = dis.read(buffer);
dos.write(buffer, 0, len);
current += len;
System.out.println(current);
}
dis.close();
dos.close();
}

From my personal experience PrintWriter and Buffers dont work well together..
As buffers trying to read data before you tell it to it can "steal" data that it should not do. For example if you use any kind of buffered reader to read the input on the server side that buffer will steal some parts at the "start" of the incomming image becuase it think's it's just another line. You could always try using DataInputStream and DataOutputStream instead..
Client:
public void sendImage(File file) {
try {
DataOutputStream out = new DataOutputStream(
socket.getOutputStream());
out.writeChar('I'); // as image,
DataInputStream dis = new DataInputStream(new FileInputStream(file));
ByteArrayOutputStream ao = new ByteArrayOutputStream();
int read = 0;
byte[] buf = new byte[1024];
while ((read = dis.read(buf)) > -1) {
ao.write(buf, 0, read);
}
out.writeLong(ao.size());
out.write(ao.toByteArray());
out.flush();
out.close();
dis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Server:
// assuming folder structure exists.
public void readImage(Socket s, File to) throws IOException {
DataInputStream dis = new DataInputStream(s.getInputStream());
char c = dis.readChar();
if (c == 'I') {
long length = dis.readLong();
DataOutputStream dos = new DataOutputStream(
new FileOutputStream(to));
byte[] buffer = new byte[1024];
int len;
while ((len = dis.read(buffer)) != -1) {
dos.write(buffer, 0, len);
}
dis.close();
dos.close();
}
}

As a starting point, in the client side, you will also need a loop for reading the local image, because are you sure that...
bis.read(byteArray,0,byteArray.length);
... is really reading the whole image? So you will also need a loop as in the server side.

Java Socket Programming Buffer for Large File

I am trying to transfer a large file from a server to a client. My code so far works but only if I set the buffer size in the client code to the exact size of the file. I won't always know what the file size is going to be. I keep finding examples that claim it doesn't matter what the size of the file or buffer is because it will just keep reading from the input stream...? However, when I implement the code that supposedly does this, it transfers 0 bytes.
Client:
public static void main (String [] args ) throws IOException {
int bytesRead;
int current = 0;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
Socket sock = null;
try {
sock = new Socket(hostname, 20000);
System.out.println("Connecting...");
// receive file
InputStream is = sock.getInputStream();
fos = new FileOutputStream(FILE_TO_RECEIVE);
bos = new BufferedOutputStream(fos);
//////////// replaced this ////////////////////////////
byte[] buffer = new byte[BUFFER_SIZE];
bytesRead = is.read(buffer,0,buffer.length);
current = bytesRead;
do {
bytesRead = is.read(buffer, current, (buffer.length-current));
if(bytesRead >= 0){ current += bytesRead;}
} while(bytesRead > 0);
bos.write(buffer, 0 , current);
///////////////////////////////////////
// with this:
// int count;
// byte[] buffer = new byte[8192];
// while ((count = is.read(buffer)) > 0)
// {
// bos.write(buffer, 0, count);
// }
//////////// transfers 0 bytes ///////////
bos.flush();
System.out.println("File " + FILE_TO_RECEIVE
+ " downloaded (" + current + " bytes read)");
}
finally {
if (fos != null){ fos.close();}
if (bos != null){ bos.close();}
if (sock != null){ sock.close();}
}
}
Server:
public static void main(String[] args) throws IOException{
FileInputStream fis = null;
BufferedInputStream bis = null;
OutputStream os = null;
ServerSocket servsock = null;
Socket sock = null;
try {
servsock = new ServerSocket(20000);
while (true) {
System.out.println("Waiting...");
try {
sock = servsock.accept();
System.out.println("Accepted connection : " + sock);
// send file
File myFile = new File (FILE_TO_SEND);
byte [] mybytearray = new byte [(int)myFile.length()];
fis = new FileInputStream(myFile);
bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
os = sock.getOutputStream();
System.out.println("Sending " + FILE_TO_SEND + "(" + mybytearray.length + " bytes)");
os.write(mybytearray,0,mybytearray.length);
os.flush();
System.out.println("Done.");
}
finally {
if (bis != null){ bis.close();}
if (os != null){ os.close();}
if (sock!=null){ sock.close();}
}
}
}
finally {
if (servsock != null){
servsock.close();
}
}
}
Thank you for your help

Your copy loops are both different, and both nonsense. One of them isn't even a loop. Try this:
while ((count = in.read(buffer)) > 0)
{
out.write(buffer, 0, count);
}
This works for any buffer of size >= one byte.
Use this at both ends.