Sending file from client to server

[kaijeong]

hi everybody,
i am new to java so i would like to ask for help from ppl have more exp than me
im trying to send file from client to server and vice versus, currently im sending test.txt file from client to server but it not work, can anyone help me pls?

this is my code

client code

import java.net.*;
import java.io.*;

public class Client {

    public static void main(String arg[]) throws IOException {

        InetAddress address = InetAddress.getByName(null);
        System.out.println("Address = " + address);
        Socket socket = new Socket(address, 8080);

        String source = "C:\\test.txt";
        byte[] buf = new byte[1000];
        int length;

        InputStream in = new BufferedInputStream(new FileInputStream(source));
        OutputStream out = new BufferedOutputStream(socket.getOutputStream());

        try {
            while ((length = in.read(buf)) > 0) {
                out.write(buf, 0, length);
            }
        }
        finally {
            out.flush();
            out.close();
            in.close();
            System.out.println("socket is closing");
            socket.close();
        }
    }
}

and server code

import java.net.*;
import java.io.*;
import java.lang.*;

public class Server {
    public static final int port = 8080;

    public static void main(String arg[]) throws IOException {

        String line;
        StringBuffer buf = new StringBuffer();
        ServerSocket p = new ServerSocket(port);
        System.out.println("Started:  " + p);
        byte[] buffer = new byte[10];

        try {
            Socket socket = p.accept();
            System.out.println("Connection accepted: " + socket);
            //copy file  code here
            try {
                BufferedInputStream in = new BufferedInputStream(socket.getInputStream());
                line = String.valueOf(in.read());
                while(true)//copy the file
                {
                    buf.append(line + "\n");
                }
            }
            finally {
                socket.close();
                System.out.println("socket is closing");
            }
        }
        finally {
            p.close();
            System.out.println("Server socket is closing");
        }
    }
}

it not print out what is on test.txt file for server side and i dont know where i got wrong
thank you in advance

[Webuser]

where do you fill this client array?

byte[] buf = new byte[1000];

[kaijeong]

i thought that is the rate of transfer data through server? doesnt it right?
thanks

[Webuser]

i thought that is the rate of transfer data through server? doesnt it right?
thanks

No :)

the array must be filled with bytes ;)

[kaijeong]

so can i change to this?

final static int BUFFER_SIZE = 1000;
byte[] buf = new byte [BUFFER_SIZE];

and then

DatagramPacket dp = new DatagramPacket (buf, buf.length);


thnks

[Webuser]

Simply :)

FileInputStream in=new FileInputStream(source));
byte [] buf=in.toString().getBytes();

for more information I recommend reading this String (Java 2 Platform SE 5.0))

[kaijeong]

thank you very much for your help, after changing , i run the program but it still not print out test.txt file on the server side. is that because the program not read into

 BufferedInputStream in = new BufferedInputStream(socket.getInputStream());
                line = String.valueOf(in.read());

on server side?

i thought that it supports to print out

test ( this is what i wrote in test.txt file)

on server side but after connection accepted, it just stands there and does nothing.
thks

[gafa]

thank you very much for your help, after changing , i run the program but it still not print out test.txt file on the server side. is that because the program not read into

 BufferedInputStream in = new BufferedInputStream(socket.getInputStream());
                line = String.valueOf(in.read());

on server side?
thks

I think you have to read each stream line on your server side :confused:

[Norm]

There are working code samples on this forum that you should look at besides reading the API doc and Tutorial. Do a search for Socket and getInputStream for examples.

[kaijeong]

thank you for helping
i have question in the same topic, " is there any way that we can download test.txt file from client ?"

thanks

[gafa]

As a rule, to read Input Streams one should use while loop :confused:

BufferedReader in=new BufferedReader(new InputStreamReader(socket.getInputStream()));


String line;
while((line=in.readLine())!=null)
{

System.out.println(line);
}

I think it is useful

[Webuser]

As a rule, to read Input Streams one should use while loop :confused:

BufferedReader in=new BufferedReader(new InputStreamReader(socket.getInputStream()));


String line;
while((line=in.readLine())!=null)
{

System.out.println(line);
}

I think it is useful

@kaijeong

As you may notice, gafa is proposing to modify you server code in this way :)

BufferedReader is a good way to read text files because it represents readLine() method to read text files line by line... Much useful

[kaijeong]

thk you for helping,
i tried rafa method to read line in text file but it not print out the result in the console.
this is what i get for server

Started:  ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=8080]
Connection accepted: Socket[addr=/127.0.0.1,port=52763,localport=8080]
(support to have msg of test.txt file here, but it not show)
socket is closing
Server socket is closing

[gafa]

Show us the client and server modified code

[kaijeong]

client code

import java.net.*;
import java.io.*;

public class Client {

    public static void main(String arg[]) throws IOException {

        InetAddress address = InetAddress.getByName(null);
        System.out.println("Address = " + address);
        Socket socket = new Socket(address, 8080);

        String source = "C:\\test.txt";
        //byte[] buf = new byte[1000];
        int length;

        //InputStream in = new BufferedInputStream(new FileInputStream(source));
        FileInputStream in = new FileInputStream(source);
        byte[] buf = in.toString().getBytes();
        OutputStream out = new BufferedOutputStream(socket.getOutputStream());

        try {
            while ((length = in.read(buf)) > 0) {
                out.write(buf, 0, length);
            }
        }
        finally {
            out.flush();
            out.close();
            in.close();
            System.out.println("socket is closing");
            socket.close();
        }
    }
}

server code

import java.net.*;
import java.io.*;
import java.lang.*;

@SuppressWarnings({"ALL"})
public class Server {
    public static final int port = 8080;

    public static void main(String arg[]) throws IOException {

        String line;
        StringBuffer buf = new StringBuffer();
        ServerSocket p = new ServerSocket(port);
        System.out.println("Started:  " + p);
        byte[] buffer = new byte[1000];

        try {
            Socket socket = p.accept();
            System.out.println("Connection accepted: " + socket);
            //copy file  code here
            try {
                BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());
                DataInputStream in = new DataInputStream(bis);
                line = String.valueOf(in.read(buffer));
                BufferedReader tin = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                
                while ((line = tin.readLine()) != null) {
                    System.out.println(line);
                }
            }
            finally {
                socket.close();
                System.out.println("socket is closing");
            }
        }
        finally {
            p.close();
            System.out.println("Server socket is closing");
        }
    }
}

[Norm]

YOU need to do some debugging. You are making too many assumptions about what is happening. For example:

  line = String.valueOf(in.read());

Instead of assuming that the byte read was OK, read the byte into a variable and display it and then display what is in the line variable.

Also show if any bytes are available by calling the available() method.

And what about exceptions? You should catch them and show an error message.

[gafa]

I think you should modify your client in this way

InetAddress address = InetAddress.getLocalHost( )

because you test it on the same machine I guess :confused:

[kaijeong]

As a rule, to read Input Streams one should use while loop :confused:

BufferedReader in=new BufferedReader(new InputStreamReader(socket.getInputStream()));


String line;
while((line=in.readLine())!=null)
{

System.out.println(line);
}

I think it is useful

i use this method but it give me error at line=in.readLine())!=null

[gafa]

getLocalHost( ) ? I cannot see it in your client code :(

[Norm]

I just compiled and executed the above program from post#15. The bytes sent by the client are read by server OK. They are in the array: buffer.

in.read(buffer)

You need to read the API doc to see what the read() method does.