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Java socket file transfer - Connection reset

I'm trying to make a program that transfer a file using java sockets. This is what I've written so far:
Sender:
private ServerSocket sendSocket;
public Send(int port) throws IOException
{
sendSocket = new ServerSocket(port);
}
public void run()
{
Socket socket = null;
try
{
Scanner scan = new Scanner(System.in);
InputStream inStream = null;
socket = sendSocket.accept();
inStream = socket.getInputStream();
String filePath = scan.nextLine();
OutputStream thisFile = new FileOutputStream(filePath);
byte[] bytes = new byte[16*1024];
int count;
while ((count = inStream.read(bytes)) > 0)
{
thisFile.write(bytes, 0, count);
}
System.out.println("Done!");
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
Receiver:
private static OutputStream thatFile;
public Receive(Socket socket) throws IOException
{
thatFile = socket.getOutputStream();
}
public void run()
{
try
{
System.out.println("Where do you want to save the file?");
Scanner scan = new Scanner(System.in);
String filePath = scan.nextLine();
File saveFile = new File(filePath);
byte[] bytes = new byte[16 * 1024];
InputStream inStream = new FileInputStream(saveFile);
int count;
while ((count = inStream.read(bytes)) > 0)
{
thatFile.write(bytes, 0, count);
}
}
catch (Exception e)
{
}
}
}
But whenever I run the program, after the client gives a destination for the download path, connection reset error happens on the sender side. I'm sure the port is open as I've tested on this port before. What's the problem?
This is what happens when I run the program:
Sender side:
Press 1 to send or 2 to receive.
1
What is the file's path?
C:\Users\orie5\Documents\Cmp\a.txt
java.net.SocketException: Connection reset
at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:323)
at java.base/sun.nio.ch.NioSocketImpl.read(NioSocketImpl.java:350)
at java.base/sun.nio.ch.NioSocketImpl$1.read(NioSocketImpl.java:803)
at java.base/java.net.Socket$SocketInputStream.read(Socket.java:966)
at java.base/java.io.InputStream.read(InputStream.java:218)
at def.Send.run(Send.java:47)
Receiver Side:
Press 1 to send or 2 to receive.
2
Please enter the ip of the peer you want to connect to.
Where do you want to save the file?
C:\Users\orie5\Documents\Cmp\b.txt
Thanks in advance!

Sent file with socket in java

I want to send file from client to server using socket.
But at the server, I only receive the first line. What is the problem?
Server Code
public static void main(String ars[]){
int port = 1000;
try {
ServerSocket sercoc = new ServerSocket(port);
System.out.println("dkjd");
while (true){
Socket soc = sercoc.accept();
InputStream flux = soc.getInputStream();
BufferedReader entree = new BufferedReader(new InputStreamReader(flux));
String message = entree.readLine();
}
} catch (IOException e) {
e.printStackTrace();
}
}
Client Code
public static void main(String args[]){
String hote = "127.00.0.1";
int port = 1000;
FileReader input = null;
File file = new File("src/view/files/temperature2.txt");
Socket soc = null;
try {
soc = new Socket(hote,port);
OutputStream flux = soc.getOutputStream();
OutputStreamWriter sortie = new OutputStreamWriter(flux);
try {
input = new FileReader("src/view/files/temperature2.txt");
char c;
while ((c = (char) input.read()) != -1){
sortie.write(c);
//sortie.write("\n");
}
} finally {
if (input != null){
input.close();
}
}
sortie.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
If I use BufferedReader I found errors and I can't receive anything!

in my code I have implemented the transfer of photo, txt and zip files through ObjectOutputStream and ObjectInputStream.
code:
// output
ObjectOutputStream objectOutput = new ObjectOutputStream(connection.clientSocket.getOutputStream());
objectOutput.writeObject(your_file);
// input
ObjectInputStream ois = new ObjectInputStream(s.getInputStream());
buffer = (byte[]) ois.readObject();

Sending a string and file into InputStream

I'm trying to send a string which is the filename and then the file itself to a server. The string is being received and used to create the file by the server. However, there isn't any data actually written into the file by the server.
I got the file transfer to work before I added the Writer's (with the file names being hard-coded) to the server and client but now I can't get both to work at the same time.
Client:
public class Client {
public static void main(String[] args) throws Exception {
Scanner sc = new Scanner(System.in);
while (true) {
String fileName = sc.nextLine();
System.out.println(fileName);
try {
File file = new File(fileName);
Socket socket = new Socket("localhost", 15000);
OutputStream os = socket.getOutputStream();
Writer w = new OutputStreamWriter(os, "UTF-8");
w.write(fileName);
w.close();
os.flush();
byte[] mybytearray = new byte[(int) file.length()];
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
bis.read(mybytearray, 0, mybytearray.length);
os.write(mybytearray, 0, mybytearray.length);
os.flush();
os.close();
socket.close();
} catch (Exception e) { }
}
}
}
Server:
public class Server extends Thread {
public static final int PORT = 15000;
#Override
public void run() {
try {
ServerSocket serverSocket = new ServerSocket(PORT);
while (true) {
Socket sock = serverSocket.accept();
readFile(sock);
}
} catch (Exception e) {
}
}
private void readFile(Socket socket) throws Exception {
InputStream ois = socket.getInputStream();
Reader r = new InputStreamReader(ois, "UTF-8");
String filename = "";
int ch = r.read();
while(ch != -1) {
filename += (char) ch;
System.out.println(filename);
ch = r.read();
}
r.close();
System.out.println(filename);
FileOutputStream fos = new FileOutputStream(filename);
byte[] bytearr = new byte[4096];
System.out.println("Reading file...");
BufferedOutputStream bos = new BufferedOutputStream(fos);
while ((ois.read(bytearr)) > 0) {
bos.write(bytearr);
}
bos.close();
System.out.println("Writing file complete...");
}
public static void main(String[] args) {
new Server().start();
}
}

This is my solution, this approach needs some improvements:
Explanation:
In position 0: Length of file name
In position 1 to the length of the file name: filename as bytes.
In position 1 + length of file name til length: The content of the file.
Basically, I'm sending all the information to the server at once (This is one improvement that you will need to figure out).
Another improvement is to send the file by chunks and not all the file at once.
Client class:
public class Client {
public static void main(String[] args) throws Exception {
Scanner sc = new Scanner(System.in);
while (true) {
String fileName = sc.nextLine();
System.out.println(fileName);
try {
File file = new File(fileName);
byte[] mybytearray = new byte[1 + fileName.getBytes().length + (int) file.length()];
mybytearray[0] = (byte) fileName.length();
System.arraycopy(fileName.getBytes(), 0, mybytearray, 1, fileName.getBytes().length);
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
bis.read(mybytearray, fileName.getBytes().length + 1, (int) file.length());
Socket socket = new Socket("localhost", 15000);
OutputStream os = socket.getOutputStream();
os.write(mybytearray, 0, mybytearray.length);
os.flush();
os.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
Server class:
public class Server extends Thread {
public static final int PORT = 15000;
public static void main(String[] args) {
new Server().start();
}
#Override
public void run() {
try {
ServerSocket serverSocket = new ServerSocket(PORT);
while (true) {
Socket sock = serverSocket.accept();
readFile(sock);
}
} catch (Exception e) {
}
}
private void readFile(Socket socket) throws Exception {
InputStream ois = socket.getInputStream();
byte[] resultBuff = new byte[0];
byte[] buff = new byte[1024];
int k;
while ((k = ois.read(buff, 0, buff.length)) > -1) {
byte[] tbuff = new byte[resultBuff.length + k];
System.arraycopy(resultBuff, 0, tbuff, 0, resultBuff.length);
System.arraycopy(buff, 0, tbuff, resultBuff.length, k);
resultBuff = tbuff;
}
byte lengthOfFileName = resultBuff[0];
byte fileNameBytes[] = new byte[lengthOfFileName];
System.arraycopy(resultBuff, 1, fileNameBytes, 0, lengthOfFileName);
String filename = new String(fileNameBytes);
FileOutputStream fos = new FileOutputStream(filename + System.currentTimeMillis());
byte[] bytearr = new byte[resultBuff.length - (lengthOfFileName + 1)];
System.out.println("Writing file...");
System.arraycopy(resultBuff, lengthOfFileName + 1, bytearr, 0, bytearr.length);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bos.write(bytearr);
bos.close();
System.out.println("Writing file complete...");
}
}
Hope this helps!
Happy coding time!

You need to close the File Ouptut Stream as well. With
bos.close;
Add
fos.close;

Multiple file chunks transfer over socket to multiple clients

I have to transfer chunks of a file to different clients using one server.
When i run the server file and provide the name of the file it successfully makes chunks. when i run the first client for first time it works but when i run it for the client again(by that i mean when i connect as a second client) it fails to transfer chunks to the second client. Complete code of server and client are shown below.
error is for the second client it starts reading the contents of the file as filename and program terminates.
provide a large text file(1MB) file as input to server
Server Code:
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.*;
public class server {
private static final int sPort = 8000; //The server will be listening on this port number
public static String str;
public static int c;
public static void main(String[] args) throws Exception {
System.out.println("The server is running.");
ServerSocket listener = new ServerSocket(sPort);
int clientNum = 1;
System.out.println("Enter the name of the file: ");
Scanner in = new Scanner(System.in);
str = in.nextLine();
String path = System.getProperty("user.dir");
String filepath = path +"/"+ str;
in.close();
try {
c=splitFile(new File(filepath));
} catch (IOException e1) {
e1.printStackTrace();
}
try {
while(true) {
new Handler(listener.accept(),clientNum,c).start();
System.out.println("Client " + clientNum + " is connected!");
clientNum++;
}
} finally {
listener.close();
}
}
/**
* A handler thread class. Handlers are spawned from the listening
* loop and are responsible for dealing with a single client's requests.
*/
private static class Handler extends Thread {
private Socket connection;
private int chunkcount;
private ObjectInputStream in; //stream read from the socket
private ObjectOutputStream out; //stream write to the socket
private int no; //The index number of the client
public Handler(Socket connection, int no,int c) {
this.connection = connection;
this.no = no;
this.chunkcount=c;
}
public void run() {
try{
//initialize Input and Output streams
out = new ObjectOutputStream(connection.getOutputStream());
out.flush();
in = new ObjectInputStream(connection.getInputStream());
try{
String path = System.getProperty("user.dir");
path=path+"/"+"chunks"+ "/";
System.out.println(path);
System.out.println("Total chunks: "+chunkcount);
int i=no;
int j=i;
int k=0;
OutputStream op=connection.getOutputStream();
DataOutputStream d = new DataOutputStream(op);
d.writeInt(no);
d.flush();
System.out.println("value of j or clientnum: "+j);
while(j<chunkcount)
{
k++;
j=j+5;
}
System.out.println(k);
d.writeInt(k);
d.flush();
//d.close();
while(i<chunkcount)
{
String pathname= path+Integer.toString(i)+str;
System.out.println(i+str);
sendFile(connection,pathname);
i=i+5;
}
}
catch(Exception e){
e.printStackTrace();
}
}
catch(IOException ioException){
System.out.println("Disconnect with Client " + no);
}
finally{
//Close connections
try{
in.close();
out.close();
connection.close();
}
catch(IOException ioException){
System.out.println("Disconnect with Client " + no);
}
}
}
}
public static int splitFile(File f) throws IOException {
int partCounter = 1;//I like to name parts from 001, 002, 003, ...
//you can change it to 0 if you want 000, 001, ...
int sizeOfFiles = 102400;// 1MB
byte[] buffer = new byte[sizeOfFiles];
try (BufferedInputStream bis = new BufferedInputStream(
new FileInputStream(f))) {//try-with-resources to ensure closing stream
String name = f.getName();
String path = f.getParent();
long sizefile = f.getTotalSpace();
String newpath = path + "/" + "chunks";
File dir = new File(newpath);
dir.mkdir();
int tmp = 0;
while ((tmp = bis.read(buffer)) > 0) {
//write each chunk of data into separate file with different number in name
File newFile = new File(dir, String.format("%d", partCounter++) + name );
//System.out.println(f.getParent());
try (FileOutputStream out = new FileOutputStream(newFile)) {
out.write(buffer, 0, tmp);//tmp is chunk size
}
}
System.out.println("File details are : "+name+" "+sizefile);
System.out.println("Number of chunks: "+ (partCounter-1));
}
return (partCounter-1);
}
public static void sendFile(Socket conn,String fileName) throws IOException
{
File myFile = new File(fileName);
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 = conn.getOutputStream();
DataOutputStream dos = new DataOutputStream(os);
dos.writeUTF(myFile.getName());
dos.writeLong(mybytearray.length);
dos.write(mybytearray, 0, mybytearray.length);
dos.flush();
dis.close();
}
}
client code:
import java.net.*;
import java.io.*;
public class Client {
Socket requestSocket; //socket connect to the server
ObjectOutputStream out; //stream write to the socket
ObjectInputStream in; //stream read from the socket
public Client() {}
void run()
{
try{
//create a socket to connect to the server
requestSocket = new Socket("localhost", 8000);
System.out.println("Connected to localhost in port 8000");
//initialize inputStream and outputStream
out = new ObjectOutputStream(requestSocket.getOutputStream());
out.flush();
in = new ObjectInputStream(requestSocket.getInputStream());
System.out.println("Ready to receive files ( Enter QUIT to end):");
BufferedInputStream in1 = new BufferedInputStream(requestSocket.getInputStream());
DataInputStream d = new DataInputStream(in1);
int clientnum=d.readInt();
String path = System.getProperty("user.dir");
String oppath = path + "/" + "Client" + clientnum;
File dir = new File(oppath);
dir.mkdir();
int numchunk=d.readInt();
System.out.println(numchunk);
int jakarta=1;
while(jakarta<=numchunk ){
jakarta++;
String newpath=oppath+"/";
File f = new File(newpath);
f.createNewFile();
receiveFile(requestSocket,newpath);
System.out.println("File Received");
}
}
catch (ConnectException e) {
System.err.println("Connection refused. You need to initiate a server first.");
}
catch(UnknownHostException unknownHost){
System.err.println("You are trying to connect to an unknown host!");
}
catch(IOException ioException){
ioException.printStackTrace();
}
finally{
//Close connections
try{
in.close();
out.close();
requestSocket.close();
}
catch(IOException ioException){
ioException.printStackTrace();
}
}
}
//send a message to the output stream
public static void receiveFile(Socket s1,String oppath) throws IOException
{
String fileName;
try {
int bytesRead;
InputStream in = s1.getInputStream();
DataInputStream clientData = new DataInputStream(in);
fileName = clientData.readUTF();
OutputStream output = new FileOutputStream(oppath+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();
output.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
//main method
public static void main(String args[])
{
Client client = new Client();
client.run();
}
}

not able to transfer Image file

hi this is my client program for transfering Image , while transfering the image file it is getting corrupted , not able to open that image file , i'm not able to identify the bug , can any one help me.
DataInputStream input = new DataInputStream(s.getInputStream());
DataOutputStream output = new DataOutputStream(s.getOutputStream());
System.out.println("Writing.......");
FileInputStream fstream = new FileInputStream("Blue hills.jpg");
DataInputStream in = new DataInputStream(fstream);
byte[] buffer = new byte[1000];
int bytes = 0;
while ((bytes = fstream.read(buffer)) != -1) {
output.write(buffer, 0, bytes);
}
in.close();

I assume that s is a Socket and you're attempting to transfer a file over the network? Here's an example of sending a file with sockets. It just sets up a server socket in a thread and connects to itself.
public static void main(String[] args) throws IOException {
new Thread() {
public void run() {
try {
ServerSocket ss = new ServerSocket(3434);
Socket socket = ss.accept();
InputStream in = socket.getInputStream();
FileOutputStream out = new FileOutputStream("out.jpg");
copy(in, out);
out.close();
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
Socket socket = new Socket("localhost", 3434);
OutputStream out = socket.getOutputStream();
FileInputStream in = new FileInputStream("in.jpg");
copy(in, out);
out.close();
in.close();
}
public static void copy(InputStream in, OutputStream out) throws IOException {
byte[] buf = new byte[8192];
int len = 0;
while ((len = in.read(buf)) != -1) {
out.write(buf, 0, len);
}
}