what I want ask is could I do something with file? which Stream is file send by ?Should file change to another data?
You can read the file using an InputStream and write its data to the OutputStream of a Socket.
This may look something like this:
OutputStream out = null;
FileInputStream in = null;
try {
// Input from file
String pathname = "path/to/file.dat";
File file = new File(pathname);
in = new FileInputStream(file);
// Output to socket
String host = "10.0.1.8";
int port = 6077;
Socket socket = new Socket(host, port);
socket.connect(endpoint); // TODO: define endpoint
out = socket.getOutputStream();
// Transfer
while (in.available() > 0) {
out.write(in.read());
}
} catch (Exception e) {
// TODO: handle exception
} finally {
if (out != null)
out.close();
if (in != null)
in.close();
}
PS: I'm not sure if this actually works. It's meant to get you started...
Related
Good day.
I am sending a string of user name (so I know the following file belongs to which user) then followed by stream of array of bytes(for audio) from android client to server running in java.
I think of opening different ports but because the server is running in a private network so if I want to open more ports then I need to add more port forwarding function which is quite silly.
I able to send string of username and arrays of bytes separately but when audio file after user name, the audio file will be sped up.
server.java
while (true) {
Socket socket = listener.accept();
try {
InputStream in = socket.getInputStream();
BufferedReader inFileN = new BufferedReader(new InputStreamReader(socket.getInputStream()));
if (fileName==null) {
fileName=inFileN.readLine();
File dir = new File("/home/xxx/Documents/" + fileName);
dir.mkdirs();
}
String filePath = "/home/xxx/Documents/"+fileName+"/voice8K16bitmono.pcm";
FileOutputStream os = null;
byte[] buffer = new byte[1024];
int count;
try {
os = new FileOutputStream(filePath);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
while ((count = in.read(buffer)) > 0)
{
os.write(buffer, 0, count);
}
} finally {
socket.close();
}
client side for writing string of user name
try {
s = new Socket("localhost", 9090);
PrintWriter out = new PrintWriter(s.getOutputStream(), true);
out.print(userID);
out.flush();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
client side for writing audio file under some condition
try {
s = new Socket("localhost", 9090);
outToServer = s.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
while (isRecording) {
recorder.read(sData, 0, BufferElements2Rec);
detectSilence(sData, threshold);
try {
byte bData[] = short2byte(sData);
//os.write(bData, 0, BufferElements2Rec * BytesPerElement);
outToServer.write(bData, 0, BufferElements2Rec * BytesPerElement);
} catch (IOException e) {
e.printStackTrace();
}
}
Or is there any other better way to use if I want to sending multiple data types from a single client?
ps: I have not implemented multi-threaded server at this point because I want to make sure it works with a single user first
Thank you.
I am trying to send a "request line" and a file through a socket.
Client (sender)
Socket socket = new Socket(hostName, SOCKET_PORT);
DataOutputStream os = new DataOutputStream(socket.getOutputStream());
FileInputStream fis = new FileInputStream(fileName);
os.writeBytes("PUT c:\dev\foo\helloworld.txt" + "\r\n")
byte[] buffer = new byte[1024];
int bytes;
while((bytes = fis.read(buffer)) != -1 ) {
try {
os.write(buffer, 0, bytes);
} catch (IOException e) {e.printStackTrace();}
}
Sever (receiver)
ServerSocket serverSocket = new ServerSocket(SOCKET_PORT);
Socket clientSoc = serverSocket.accept();
InputStream inputStream = clientSoc.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String requestLine = bufferedReader.readLine();
File currentFile = (File)new ObjectInputStream(inputStream).readObject(); //This doesn't work
byteSequence = new byte[new Long(currentFile.length()).intValue()];
for(int i =0; i<currentFile.length();i++){
byteSequence[i] = (byte)clientSoc.getInputStream().read();
}
try {
FileOutputStream newFile = new FileOutputStream(currentFile.getName());
newFile.write(byteSequence,0, byteSequence.length);
} catch (IOException e) {e.printStackTrace();}
I am able to read the request line on the server but when I attempt to read the file it throws an exception (line below).
File currentFile = (File)new ObjectInputStream(inputStream).readObject();
java.io.Stream.CorruptedException:
java.io.StreamCorruptedException: invalid stream header: 0A48656C
What exactly am I doing wrong?
You are trying to access an object that was not even passed to the socket.. you only passed a byte of string to the server but you never pass an Object to the server using the ObjectOutputStream..
I'm writing a program to download/upload a file between a client and server using socket programming. The code i've written till now works in the sense that i can sucesfully transfer files. However , if a connection fails due to problem in the network/client/server while a download / upload is occuring.. i need to RESUME the download/upload from the original point(Do not want the originally sent data to be resent). I'm not sure how to go about this. I'm reading the file into a byte array and sending it across the network. My initial idea is that everytime i'm downloading.. i should check if the file already exists and read the data into a byte array --> send the data to the server for comparison and then return the remaining data from the server file by comparing the two byte arrays. But this seems inefficient and takes away the point of resuming a download(since i'm sending the data again).
Note: The file name is an unique identifier.
I would really appreciate it if anybody could give me suggestions as to how i should implement the file resume functionality?
Server side code:
package servers;
import java.io.*;
import java.net.*;
import java.util.Arrays;
public class tcpserver1 extends Thread
{
public static void main(String args[]) throws Exception
{
ServerSocket welcomeSocket = null;
try
{
welcomeSocket = new ServerSocket(5555);
while(true)
{
Socket socketConnection = welcomeSocket.accept();
System.out.println("Server passing off to thread");
tcprunnable tcprunthread = new tcprunnable(socketConnection);
Thread thrd = new Thread(tcprunthread);
thrd.start();
System.out.println(thrd.getName());
}
}
catch(IOException e){
welcomeSocket.close();
System.out.println("Could not connect...");
}
}
}
class tcprunnable implements Runnable
{
Socket socke;
public tcprunnable(Socket sc){
socke = sc;
}
public void download_server(String file_name)
{
System.out.println("Inside server download method");
try
{
System.out.println("Socket port:" + socke.getPort());
//System.out.println("Inside download method of thread:clientsentence is:"+clientSentence);
// Create & attach output stream to new socket
OutputStream outToClient = socke.getOutputStream();
// The file name needs to come from the client which will be put in here below
File myfile = new File("D:\\ "+file_name);
byte[] mybytearray = new byte[(int) myfile.length()];
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(myfile));
bis.read(mybytearray, 0, mybytearray.length);
outToClient.write(mybytearray, 0, mybytearray.length);
System.out.println("Arrays on server:"+Arrays.toString(mybytearray));
outToClient.flush();
bis.close();
}
catch(FileNotFoundException f){f.printStackTrace();}
catch(IOException ie){
ie.printStackTrace();
}
}
public void upload_server(String file_name){
try{
byte[] mybytearray = new byte[1024];
InputStream is = socke.getInputStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
FileOutputStream fos = new FileOutputStream("D:\\ "+file_name);
BufferedOutputStream bos = new BufferedOutputStream(fos);
int bytesRead = is.read(mybytearray, 0, mybytearray.length);
bos.write(mybytearray, 0, bytesRead);
do {
baos.write(mybytearray);
bytesRead = is.read(mybytearray);
}
while (bytesRead != -1);
bos.write(baos.toByteArray());
System.out.println("Array on server while downloading:"+Arrays.toString(baos.toByteArray()));
bos.close();
}
catch(FileNotFoundException fe){fe.printStackTrace();}
catch(IOException ie){ie.printStackTrace();}
}
#Override
public void run()
{
try
{
System.out.println("Server1 up and running" + socke.getPort());
// Create & attach input stream to new socket
BufferedReader inFromClient = new BufferedReader
(new InputStreamReader(socke.getInputStream()));
// Read from socket
String clientSentence = inFromClient.readLine();
String file_name = inFromClient.readLine();
System.out.println("Sever side filename:" + file_name);
try{
if(clientSentence.equals("download"))
{
download_server(file_name);
}
else if(clientSentence.equals("upload"))
{
upload_server(file_name);
System.out.println("Sever side filename:" + file_name);
}
else
{
System.out.println("Invalid input");
}
}
catch(NullPointerException npe){
System.out.println("Invalid input!");
}
socke.close();
}
catch(IOException e)
{
e.printStackTrace();
System.out.println("Exception caught");
}
}
}
Client side code:
package clients;
import java.io.*;
import java.net.*;
import java.util.Arrays;
public class tcpclient1
{
public static void main (String args[]) throws Exception
{
// Create input stream to send sentence to server
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
Socket clientSocket = null;
while(true){
System.out.println("Please enter the server you want to use");
System.out.println("Enter 1 for Server 1 and 2 for Server2");
String server_choice = inFromUser.readLine();
if(server_choice.equals("1")){
// Create client socket to connect to server
// The server to use will be specified by the user
clientSocket = new Socket("localhost",5555);
break;
}
else if(server_choice.equals("2"))
{
clientSocket = new Socket("localhost",5556);
break;
}
else
{
System.out.println("Invalid entry");
}
}
System.out.println("Please enter download for dowloading");
System.out.println("Please enter upload for uploading");
// sentence is what'll be received from input jsp
String sentence = inFromUser.readLine();
if(sentence.equals("download"))
{
download_client(clientSocket,sentence);
}
else if(sentence.equals("upload"))
{
upload_client(clientSocket,sentence);
}
else
{
System.out.println("Invalid input");
}
clientSocket.close();
}
public static void download_client(Socket clientSocket , String sentence)
{
try{
// Create output stream attached to socket
DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
// Send line to server
outToServer.writeBytes(sentence+'\n');
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the name of file to download:");
String file_to_download = inFromUser.readLine();
if(searching(file_to_download))
{
// Read local file and send that to the server for comparison
// DONT THINK THIS IS THE RIGHT WAY TO GO ABOUT THINGS SINCE IT BEATS THE PURPOSE OF RESUMING A DOWNLOAD/UPLOAD
}
// Send filetodownload to server
outToServer.writeBytes(file_to_download+'\n');
byte[] mybytearray = new byte[1024];
InputStream is = clientSocket.getInputStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
FileOutputStream fos = new FileOutputStream("E:\\ "+file_to_download);
BufferedOutputStream bos = new BufferedOutputStream(fos);
int bytesRead = is.read(mybytearray, 0, mybytearray.length);
bos.write(mybytearray, 0, bytesRead);
do {
baos.write(mybytearray);
bytesRead = is.read(mybytearray);
}
while (bytesRead != -1);
bos.write(baos.toByteArray());
System.out.println("Array on client while downloading:"+Arrays.toString(baos.toByteArray()));
bos.close();
}
catch(FileNotFoundException fe){fe.printStackTrace();}
catch(IOException ie){ie.printStackTrace();}
}
public static void upload_client(Socket clientSocket, String sentence)
{
try{
// Create output stream attached to socket
DataOutputStream outToServer1 = new DataOutputStream(clientSocket.getOutputStream());
// Send line to server
outToServer1.writeBytes(sentence+'\n');
System.out.println("In the client upload method");
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the name of file to upload:");
String file_to_upload = inFromUser.readLine();
//System.out.println("Cline side file name:"+file_to_upload);
outToServer1.writeBytes(file_to_upload+'\n');
System.out.println(file_to_upload);
OutputStream outtoserver = clientSocket.getOutputStream();
File myfile = new File("E:\\ "+file_to_upload);
byte[] mybytearray = new byte[(int) myfile.length()];
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(myfile));
bis.read(mybytearray, 0, mybytearray.length);
outtoserver.write(mybytearray, 0, mybytearray.length);
System.out.println("filename:"+file_to_upload+"Arrays on client while uploading:"+Arrays.toString(mybytearray));
outtoserver.flush();
bis.close();
}
catch(FileNotFoundException fe){fe.printStackTrace();}
catch(IOException ie){ie.printStackTrace();}
}
public static boolean searching(String file_name)
{
String file_path = "E:\\ "+file_name;
File f = new File(file_path);
if(f.exists() && !f.isDirectory()) { return true; }
else
return false;
}
}
The above code runs fine for transferring files between the client and server.
Again , would really appreciate any help!
There are many ways which you can do this, I suggest you to create a separate type of request to the server that accepts the file's name and file position which is the position where in the file where the connection failed.
That's how you will get the file from the server in the client's side:
int filePosition = 0;
InputStream is = clientSocket.getInputStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
do {
baos.write(mybytearray);
bytesRead = is.read(mybytearray);
if(bytesRead != -1)
filePosition += bytesRead;
}
while (bytesRead != -1);
Now if the connection got interrupted for some reason you can send a request again to the server with the same file name and the filePosition, and the server will send the file back like this:
OutputStream outToClient = socke.getOutputStream();
// The file name needs to come from the client which will be put in here below
File myfile = new File("D:\\ "+file_name);
byte[] mybytearray = new byte[(int) myfile.length()];
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(myfile));
bis.skip(filePosition) //Advance the stream to the desired location in the file
bis.read(mybytearray, 0, mybytearray.length);
outToClient.write(mybytearray, 0, mybytearray.length);
System.out.println("Arrays on server:"+Arrays.toString(mybytearray));
outToClient.flush();
bis.close();
And in the client you can open the file stream and specify append = true in the constructor like this:
FileOutputStream fos = new FileOutputStream("D:\\ "+file_name, true);
This could be one way to do this, there are a lot more options. And I also suggest verify the files after the transfer using some hash function like MD5 for example, it creates unique stamp for a given input and it always outputs same result for the same input, which means, you can create the stamp from the same file both in the server and in the client and if the file is truly the same, it will generate the same stamp. Since the stamp's size is very small relative to the file it self and it is also fixed, it can be send between the client/server without much overhead.
You can generate an MD5 hash with this code:
MessageDigest md = MessageDigest.getInstance("MD5");
try (InputStream is = Files.newInputStream(Paths.get("file.txt"))) {
DigestInputStream dis = new DigestInputStream(is, md);
/* Read stream to EOF as normal... */
}
byte[] digest = md.digest();
(taken from: Getting a File's MD5 Checksum in Java)
Basically, when requesting a download You should attach information about how many bytes need to be skipped (0 on new download). You should get this information from part of the file that you have downloaded (read it's size). Server should skip given count of bytes and send back the remainder of file. Client should append this to the existing file. For sanity check, You could add some file hash checking in the end, to ensure You got the file correctly.
I want to download a file from a Server into a client machine. But i want the file to be downloaded from a browser : I want the file to be saved at the Downloads Folder.
Im using the following code to download files.
public void descarga(String address, String localFileName) {
OutputStream out = null;
URLConnection conn = null;
InputStream in = null;
try {
// Get the URL
URL url = new URL(address);
// Open an output stream to the destination file on our local filesystem
out = new BufferedOutputStream(new FileOutputStream(localFileName));
conn = url.openConnection();
in = conn.getInputStream();
// Get the data
byte[] buffer = new byte[1024];
int numRead;
while ((numRead = in.read(buffer)) != -1) {
out.write(buffer, 0, numRead);
}
// Done! Just clean up and get out
} catch (Exception exception) {
exception.printStackTrace();
} finally {
try {
if (in != null) {
in.close();
}
if (out != null) {
out.close();
}
} catch (IOException ioe) {
// Shouldn't happen, maybe add some logging here if you are not
// fooling around ;)
}
}
It works but unless i specify the absolute path it does not download the file, therefore is useless to use from different clients with different browsers, because the webpage does not even prompts the message that lets the user know that a file is being downloaded. What can i add to get that to work?
Thanks
I'm having a tough time figuring something out. (I'm pretty new to all this.)
I wrote this java pgm to ftp a large file to a destination server.
Here's the code (codes been modified a bit for display):
public static void ftpUpload(String path, String upfileName, String dirName) throws Exception
{
FTPClient client = new FTPClient();
client.addProtocolCommandListener((ProtocolCommandListener) new PrintCommandListener(new PrintWriter(System.out)));
client.enterLocalPassiveMode();
FileInputStream fis = null;
int reply;
try {
client.connect(ftpserver);
client.login(ftpuserid, ftppasswd);
reply = client.getReplyCode();
if(FTPReply.isPositiveCompletion(reply)){
client.changeWorkingDirectory(ftpdirectoryName + "/" + dirName);
boolean mkDir = client.makeDirectory(getCurrentMMMYY().toLowerCase());
client.changeWorkingDirectory(getCurrentMMMYY().toLowerCase());
//Create an InputStream of the file to be uploaded
fis = new FileInputStream(path + upfileName);
//Store file to server
client.storeFile(upfileName, fis);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (fis != null) {
fis.close();
}
client.logout();
//client.disconnect();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Something weird is happening on files I'm sending...
One of my files on the origination server is 82575786 in size, and when I ftp this file it almost sends the entire file. It actually sends 82574867. (missing 919)
Another file on the origination server is 717885, and when I ftp this file it almost sends the entire file. It actually sends 717522. (missing 363)
I pulled the log to see if something crashed, but it didn't show anything wrong with the transfer. Here are the 2 log entries showing the transfer.
[08/09/11 20:21:13:618 EDT] 00000043 SystemOut O 221-You have transferred 717522 bytes in 1 files.
221-You have transferred 82574867 bytes in 1 files.
Anyone's help would greatly be appreciated.
Thanks
Dan.
Are you transferring in ASCII mode instead of binary? ASCII mode converts CR/LF to LF and vice-versa depending on server and client settings.
Are you using Apache's FTP client? It says the default is ASCII, you could try setting BINARY_FILE_TYPE with setFileType:
client.setFileType(FTPClient.BINARY_FILE_TYPE);
To upload a binary File you have to use the FTP.BINARY_FILE_TYPE but is not enough.
You are using only an INPUT stream, and you need to use an outputstream too
I hope that this example will help you:
FTPClient client = new FTPClient();
client.connect("192.168.30.20");
client.login("pwd", "pwd");
client.setFileType(FTP.BINARY_FILE_TYPE);
String path_base = "/myPath/";
InputStream fis = new FileInputStream("A.pdf");
OutputStream os = client.storeFileStream(path_base+ "B.pdf");
byte buf[] = new byte[8192];
int bytesRead = fis.read(buf);
while (bytesRead != -1) {
os.write(buf, 0, bytesRead);
bytesRead = fis.read(buf);}
fis.close();
os.close();
client.completePendingCommand();
client.logout();
client.disconnect();