I have stucked for 4h already with the sockets, the way I am using is is that there is only one application as client and server, once the client connect it is opening the theard with new client and waiting for message.
Once the message is send to the server, the client will receive respond, that part is working without any problems.
Part of the Client Theard:
while (true)
{
InputStreamReader IR = new InputStreamReader(clientSocket.getInputStream());
BufferedReader BR = new BufferedReader(IR);
PrintStream PS = new PrintStream(clientSocket.getOutputStream());
String message = BR.readLine();
if (message != null)
{
System.out.println(clientSocket.getInetAddress() + ":" + clientSocket.getPort() + " has connected."+message);
if (message.equals("exit"))
{
PS.println("Exiting...");
exit();
}
else if (message.equals("list"))
{
getList(PS);
}
else if ((message.contains("get") && (message.contains(",") && (message.contains(" ")))))
{
String[] spliter = message.split(" ");
String[] file = spliter[1].split(",");
String file_name = file[0];
String file_md5 = file[1];
getFile(file_name, file_md5, clientSocket);
}
}
else
{
break;
}
}
There are 2 messages that the server is supporting, the first one is "list" and the send one command is "get with values".
if client will request command "list" it will run this:
There is a "server/client", it is sending request and receive the one line string and it is working without any problem, I am receiving the list of files from the server.
PrintStream PS = new PrintStream(clientSocket.getOutputStream());
PS.println("list");
InputStreamReader IR = new InputStreamReader(clientSocket.getInputStream());
BufferedReader BR = new BufferedReader(IR);
String lista_plikow = BR.readLine();
if ( lista_plikow != null)
{
return lista_plikow;
}
But I have problems to send the files over the sockets using code found on stackoverflow, but the "receiving" is not working, there is my receive function, the loop is always as 0 (even if first bytes length is correct), but the length of the bytes is correct, it is using newly created file but nothing is happening, the file is always on use, and has 0 bytes instead of content of the PS.println.
PrintStream PS = new PrintStream(clientSocket.getOutputStream());
PS.println("get "+filename+","+file_md5);
int bytesRead;
int current = 0;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
try
{
byte [] mybytearray = new byte [Integer.parseInt(size)];
InputStream is = clientSocket.getInputStream();
fos = new FileOutputStream(filename + ".recived");
bos = new BufferedOutputStream(fos);
bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead;
System.out.println("X" + bytesRead);
do {
bytesRead =
is.read(mybytearray, current, (mybytearray.length-current));
System.out.println(bytesRead + " = " + current + " " + (mybytearray.length-current));
if(bytesRead >= 0) current += bytesRead;
System.out.println(bytesRead);
} while(bytesRead > -1);
bos.write(mybytearray, 0 , current);
bos.flush();
System.out.println("File " + "recived." +filename.replace(":", " ")
+ " downloaded (" + current + " bytes read)");
}catch (Exception e)
{
System.out.println(e.getMessage());
}
And last part of the scrip the "PS.println("get "+filename+","+file_md5);" is doing exactly this one, the sending is working fine:
FileInputStream fis = null;
BufferedInputStream bis = null;
OutputStream os = null;
String the_file = TorrentAppGui.folder+"\\"+file_name.replace(":", " ");
File myFile = new File (the_file);
byte [] mybytearray = new byte [(int)myFile.length()];
fis = new FileInputStream(myFile);
bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
os = clientSocket.getOutputStream();
System.out.println("Sending " + the_file + "(" + mybytearray.length + " bytes)");
os.write(mybytearray, 0, mybytearray.length);
os.flush();
System.out.println("Done.");
I have no idea why I cannot save the bytes received by the "get" command, do you have any ideas?
I know that only the "receve" function is not working, because if I looged to the application via telnet I could get the file in the console, but it doesnt reach my target. See the screen from cli.
You can't mixed buffered and unbuffered streams/readers/writers on the same socket. You will lose data in the buffers. Use the same stream pair for the life of the socket. In this case I would use DataInputStream and DataOutputStream, and the readUTF()/writeUTF() methods for the messages and filenames. You will also need to send the file length ahead of the file, unless the file is the last thing sent over the connection: otherwise the peer won't know when to stop reading the file and go back and start reading messages again.
Related
I'm having issues with this question right now.
For this question, I have to:
Client side: compress each input line from the console, send it to the server and decompress each message from server
Server side: decompress data from client, change the lower-case letters to upper case, compress it and send back to the client
The best I can do is do everything above with only ONE line.
Client Side:
/* SOCKET CONNECTING STUFF UP HERE */
/*PROBLEMS START AROUND HERE */
String line;
BufferedReader bis = new BufferedReader(new InputStreamReader(System.in));
DeflaterOutputStream compress = new DeflaterOutputStream(socket.getOutputStream(), true);
InflaterInputStream decompress = new InflaterInputStream(socket.getInputStream());
BufferedReader fromClient = new BufferedReader(new InputStreamReader(decompress));
line = bis.readLine();
line = line + "\n";
compress.write(line.getBytes(), 0, line.length());
compress.finish();
System.out.println("Message sent: " + line);
System.out.println("Message Returned : " +fromClient.readLine());
/* closing the streams here */
bis.close();
decompress.close();
compress.close();
fromClient.close();
socket.close();
}
}
Server Side:
String line = "";
OutputStream outstream = new FileOutputStream("compessserver.txt");
InflaterInputStream decompress = new InflaterInputStream(clientsocket.getInputStream());
BufferedReader fromClient = new BufferedReader(new InputStreamReader(decompress));
DeflaterOutputStream compress = new DeflaterOutputStream(clientsocket.getOutputStream());
while ((line = fromClient.readLine()) != null) {
String upperLine = line.toUpperCase();
System.out.println("Message received and converted: " + upperLine);
System.out.println();
upperLine = upperLine + "\n";
byte[] input = upperLine.getBytes();
outstream.write(input);
outstream.write("\r\n".getBytes());
compress.write(input);
System.out.println("Message returned : " + upperLine);
compress.finish();
if (upperLine.equalsIgnoreCase("x")) {
break;
}
}
decompress.close();
compress.close();
fromClient.close();
outstream.close();
socket.close();
}
}
I really need help in this please. If I try to make this multiple inputs instead, the whole code just messes up. Been at this for days.
EDIT: Forgot to mention this. What I'm supposed to do is input a line, compress it, send to server, server decompress it and upper case letters, compress it, send back to client. And then I supposed to input more lines until I put in a single letter like "Q" which in case, ends the program
I tried the following code to make it work for multiple lines
Second Try Client Side:
String line;
BufferedReader bis = new BufferedReader(new InputStreamReader(System.in));
DeflaterOutputStream compress = new DeflaterOutputStream(socket.getOutputStream(), true);
InflaterInputStream decompress = new InflaterInputStream(socket.getInputStream());
BufferedReader fromClient = new BufferedReader(new InputStreamReader(decompress));
line = bis.readLine();
while ((!line.equalsIgnoreCase("x"))) {
compress.write(line.getBytes(), 0, line.length());
System.out.println("Message sent: " + line);
System.out.println("Message returned:" +fromClient.readLine() );
line = bis.readLine();
}
bis.close();
fromClient.close();
socket.close();
}
}
Second Try Server Side:
OutputStream outstream = new FileOutputStream("compessserver.txt");
InflaterInputStream decompress = new InflaterInputStream(clientsocket.getInputStream());
BufferedReader fromClient = new BufferedReader(new InputStreamReader(decompress));
DeflaterOutputStream compress = new DeflaterOutputStream(clientsocket.getOutputStream());
while ((line = fromClient.readLine()) != null) {
String upperLine = line.toUpperCase();
System.out.println("Message received and converted: " + upperLine);
System.out.println();
upperLine = upperLine + "\n";
byte[] input = upperLine.getBytes();
outstream.write(input);
outstream.write("\r\n".getBytes());
compress.write(input);
System.out.println("Message returned : " + upperLine);
if (upperLine.equalsIgnoreCase("x")) {
break;
}
}
decompress.close();
fromClient.close();
outstream.close();
socket.close();
}
}
You can't use these streams interactively. You would have to call finish() after every write, or rather before every read, which means you could only do one write. They are designed for large one-way streams, not interactive request/response sessions.
In any case there is no advantage to be gained from compressing single lines. You need a lot of data for compression to start working.
NB compress.write(line.getBytes(), 0, line.length()) isn't valid. It assumes the number of chars in the String is the same as the number of bytes when converted, which isn't always so. It should be compress.write(line.getBytes(), 0, line.getBytes().length()), or more simply compress.write(line.getBytes()).
I am sending files to remote Android client from java server. I write the bytes using outputstream. On reading these bytes read() method keep trying to read bytes after the stream is ended. if I close the outputstream on server-side, read operation work fines. But I have to write file on the same socket again so can't close output stream any solution?
NOTE: MY CODE WORKS FINE FOR SHARING SINGLE FILE
CODE FOR WRITING FILE
public static void writefile(String IP, String filepath, int port, OutputStream out) throws IOException {
ByteFileConversion bfc = new ByteFileConversion();
byte[] file = bfc.FileToByteConversion(filepath);
out.write(file, 0, file.length);
out.close(); // i donot want to close this and how can I tell reading side that stream is ended.
System.out.println("WRITTEN");
}
Here Am I reading the file on Android :
public Bitmap fileReceived(InputStream is) {
Bitmap bitmap = null;
String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
String fileName = "a.png";
String imageInSD = baseDir + File.separator + fileName;
// System.out.println(imageInSD);
if (is != null) {
FileOutputStream fos = null;
OutputStream bos = null;
try {
bos = new FileOutputStream(imageInSD);
byte[] aByte = new byte[1024];
int bytesRead;
int index = 0;
DataInputStream dis = new DataInputStream(is);
while ((bytesRead = is.read(aByte)) > 0) {
index = bytesRead + index;
bos.write(aByte, 0, bytesRead);
// index = index+ bytesRead;
System.out.println("Loop" + aByte + " byte read are " + bytesRead + "whree index =" + index);
}
bos.flush();
bos.close();
Log.i("IMSERVICE", "out of loop");
java.io.FileInputStream in = new FileInputStream(imageInSD);
bitmap = BitmapFactory.decodeStream(in);
bitmap = BitmapFactory.decodeFile(imageInSD);
Log.i("IMSERVICE", "saved");
// if (bitmap != null)
// System.out.println("bitmap is "+ bitmap.toString());
} catch (IOException ex) {
// Do exception handling
// Log.i("IMSERVICE", "exception ");
System.out.println("ex");
}
}
return bitmap;
}
Actually, I want to reset socket connection
Thanks in advance
You need to:
Send the length of the file ahead of the file. You can use DataOutputStream.writeLong() for that, and DataInputStream.readLong() at the receiver.
Read exactly that many bytes from the stream at the receiver:
while (total < length && (count = in.read(buffer, 0, length-total > buffer.length ? buffer.length : (int)(length-total))) > 0)
{
out.write(buffer, 0, count);
total += count;
}
E&OE
Actually I want to reset socket connection
Actually you don't want to do any such thing.
If i donot close outputstream the read operation on other side stuck on keep reading
That is because the client socket's InputStream is still waiting for the server to send some packets of data thus blocking your Main Thread.
Solution:
You can put each of your sending(OutputStream) and reading(InputStream) of packets of data from the socket to a Thread to prevent blocking your main thread when reading and sending.
Create a thread that reads the InputStream and another one for the OutputStream
Side note:
Don't try to close your outputStream that it cant be reopened again as the documentation is saying:
Closing the returned OutputStream will close the associated socket.
The general contract of close is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.
Hallo i an trying to send Firmware file to modem board thru telnet.
Here is my code:
Socket s = null;
try {
SocketAddress socketAddress = new InetSocketAddress(InetAddress.getByName(addr), 23);
s = new Socket();
s.connect(socketAddress, 1000);
InputStream inputStream = s.getInputStream();
OutputStream outputStream = s.getOutputStream();
outputStream.write( (login + "\n") .getBytes());
Thread.sleep(300);
outputStream.write( (password + "\n") .getBytes());
Thread.sleep(300);
outputStream.write(("swupdate" + "\n").getBytes());
Thread.sleep(300);
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream(path_frm_vdsl);
// Get the object of DataInputStream
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String line;
// Read File Line By Line
while ((line = br.readLine()) != null) {
// Print the content on the console
line = br.readLine();
if (line == null) {
Thread.sleep(1000);
} else {
//System.out.println(line);
outputStream.write(line.getBytes());
Log.v("---", line.getBytes() + "" + consumeInput(500, inputStream));
//Log.v("Update_Modem","Updated " + consumeInput(500, inputStream));
//outputStream.write(line.getBytes());
Thread.sleep(10);
}
}
It simply logs in sends swupdate command and dumps firmware file to output. After first line of input i am having java.net.SocketException: Broken pipe
And i can not read all file at once, not enough memory exception. (3Mb)
You know telnet uses in-channel signalling? the data stream contains escaped command instructions. When you open a telnet connection, a whole slew of initial commands are passed back and forth, as the server and client determine each others capabilities and preferences.
You may well find your byte stream is corrupted, if you just take whatever you get turning up at the server. You will need to honour the telnet protocol, e.g. properly understand the byte stream you're receiving.
The line terminator in the Telnet protcol is \r\n.
But why would you want to read the whole file into memory? And why all the sleeps? And why are you skipping every second line? And what is consumeInput()?
Just read and write bytes.
Not sure how your receiving end wants the firmware, plain binary, hex encoded, base64 encoded?
Anyway, here is how you would send it in plain binary
Socket s = null;
try {
SocketAddress socketAddress = new InetSocketAddress(InetAddress.getByName(addr), 23);
s = new Socket();
s.connect(socketAddress, 1000);
InputStream inputStream = s.getInputStream();
OutputStream outputStream = s.getOutputStream();
outputStream.write((login + "\n").getBytes());
Thread.sleep(300);
outputStream.write((password + "\n").getBytes());
Thread.sleep(300);
outputStream.write(("swupdate" + "\n").getBytes());
Thread.sleep(300);
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream(path_frm_vdsl);
byte[] buffer = new byte[1024];
int fillSize;
// Read File chunk by chunk
while ((fillSize = fstream.read(buffer)) != -1) {
outputStream.write(buffer, 0, fillSize);
}
outputStream.close();
} finally {
s.close();
}
So, read the file in chunks until there is no more data (read returns -1) and write the chunk (read returns how much was actually read).
I got working over socket file sender, it worked perfectly, but I couldn't send large files with it. Always got heap error. Then I changed the code of client, so it would send file in chunks. Now I can send big files, but there is new problem. Now I recieve small files empty and larger files for example videos can't be played. Here is the code of client that sends file:
public void send(File file) throws UnknownHostException, IOException {
// Create socket
hostIP = "localhost";
socket = new Socket(hostIP, 22333);
//Send file
FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
DataInputStream dis = new DataInputStream(bis);
OutputStream os = socket.getOutputStream();
//Sending size of file.
DataOutputStream dos = new DataOutputStream(os);
dos.writeUTF(file.getName() + ":" + userName);
byte[] arr = new byte[1024];
try {
int len = 0;
while ((len = dis.read(arr)) != -1) {
dos.write(arr, 0, len);
}
} catch (IOException ex) {
ex.printStackTrace();
}
dos.flush();
socket.close();
}
and here is the server code:
void start() throws IOException {
// Starts server on port.
serverSocket = new ServerSocket(port);
int bytesRead;
while (true) {
connection = serverSocket.accept();
in = connection.getInputStream();
clientData = new DataInputStream(in);
String[] data = clientData.readUTF().split(":");
String fileName = data[0];
String userName = data[1];
output = new FileOutputStream("C:/" + fileName);
long size = clientData.readLong();
byte[] buffer = new byte[1024];
// Build new file
while (size > 0 && (bytesRead = clientData.read(buffer, 0, (int) Math.min(buffer.length, size))) != -1) {
output.write(buffer, 0, bytesRead);
size -= bytesRead;
}
output.close();
}
}
You failed to write out the length of the file to the stream in the client:
long size = clientData.readLong();
So that call in the server is reading the first 8 bytes of the actual file and who knows what that quantity is. You don't have to read the length from the stream since you only wrote a single file. After reading the filename, and username (not very secure is it?) you can just read the stream until EOF. If you ever wanted to send multiple files over the same open socket then you'd need to know the length before reading the file.
Also your buffers for reading are way to small. You should be at a minimum of 8192 instead of 1024. And you'll want to put all .close() in a finally block to make sure your server and clients shutdown appropriately if there is an exception ever.
I want to make my server to be able to get the name of the file that will be sent to it and then after getting that file it could save it in new location with right name.
Here is the server code:
class TheServer {
public void setUp() throws IOException { // this method is called from Main class.
ServerSocket serverSocket = new ServerSocket(1991);
System.out.println("Server setup and listening...");
Socket connection = serverSocket.accept();
System.out.println("Client connect");
System.out.println("Socket is closed = " + serverSocket.isClosed());
BufferedReader rd = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String str = rd.readLine();
System.out.println("Recieved: " + str);
rd.close();
InputStream is = connection.getInputStream();
int bufferSize = connection.getReceiveBufferSize();
FileOutputStream fos = new FileOutputStream("C:/" + str);
BufferedOutputStream bos = new BufferedOutputStream(fos);
byte[] bytes = new byte[bufferSize];
int count;
while ((count = is.read(bytes)) > 0) {
bos.write(bytes, 0, count);
}
bos.flush();
bos.close();
is.close();
connection.close();
serverSocket.close();
}
}
and here is the client code:
public class TheClient {
public void send(File file) throws UnknownHostException, IOException { // this method is called from Main class.
Socket socket = null;
String host = "127.0.0.1";
socket = new Socket(host, 1991);
// Get the size of the file
long length = file.length();
if (length > Integer.MAX_VALUE) {
System.out.println("File is too large.");
}
BufferedWriter wr = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
wr.write(file.getName());
wr.flush();
byte[] bytes = new byte[(int) length];
FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
BufferedOutputStream out = new BufferedOutputStream(socket.getOutputStream());
int count;
while ((count = bis.read(bytes)) > 0) {
out.write(bytes, 0, count);
}
out.flush();
out.close();
fis.close();
bis.close();
socket.close();
}
}
I made few test of my own and it seems that my client is sending the name of the file right, but somehow server gets it wrong. For example if my client tells that name of the file is "test.txt" my server gets it for example like "test.txt´--------------------" or "test.txtPK". I can't understand why it does't get the name normally. Anyone knows why this happens? Or is there an easier way to do this? And my second question is, how can I use this not only in localhost but everywhere? I tried changing my host to my IP adress but it didnt work. Thanks.
You never send end of line after the filename. Therefore, when server reads using readLine() it will read all characters until it find first end of line which may be somewhere in file content. Sometimes it's after '-----' and sometimes after 'PK'.