hello,

i have to write a java code using socket programming to transfer all the files from one server to another server keeping the size of the files intact (i.e create a backup of the files in another server). i am new to socket programming. so i would really appreciate if someone can help me with the code.

thanks.

i have written a java code to transfer files from one server to another using the concept of socket programming. now in the same code i also want to check for the network connection availability before each file is transferred. i also want that the files transferred should be transferred according to their numerical sequence. And while the files are being transferred the transfer progress of each file i.e the progress percentage bar should also be visible on the screen.

i will really appreciate if someone can help me with the code. i am posting the code i have written for file transfer.

[co
1. ClientMain.java and DirectoryTxr.java are the two classes under client application. ServerMain.java and DirectoryRcr.java are the two classes under Server application.
2. run the ClientMain.java and ServerMain.java

[B](ClientMain.java)[/B]

import java.io.*;
import java.net.Socket;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class ClientMain {
    private DirectoryTxr transmitter = null;
    Socket clientSocket = null;
    private boolean connectedStatus = false;
    private String ipAddress;
    String srcPath = null;
    String dstPath = "";
    public ClientMain() {

    }

    public void setIpAddress(String ip) {
        this.ipAddress = ip;
    }

    public void setSrcPath(String path) {
        this.srcPath = path;
    }

    public void setDstPath(String path) {
        this.dstPath = path;
    }

    private void createConnection() {
        Runnable connectRunnable = new Runnable() {
            public void run() {
                while (!connectedStatus) {
                    try {
                        clientSocket = new Socket(ipAddress, 3339);
                        connectedStatus = true;
                        transmitter = new DirectoryTxr(clientSocket, srcPath, dstPath);
                    } catch (IOException io) {
                        io.printStackTrace();
                    }
                }

            }
        };
        Thread connectionThread = new Thread(connectRunnable);
        connectionThread.start();
    }

    public static void main(String[] args) {
        ClientMain main = new ClientMain();
        main.setIpAddress("10.6.3.92");
        main.setSrcPath("E:/temp/movies/");
        main.setDstPath("D:/tcp/movies");
        main.createConnection();

    }
}

[B](DirectoryTxr.java)[/B]

import java.io.*;
import java.net.Socket;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class DirectoryTxr {
    Socket clientSocket = null;
    String srcDir = null;
    String dstDir = null;
    byte[] readBuffer = new byte[1024];
    private InputStream inStream = null;
    private OutputStream outStream = null;
    int state = 0;
    final int permissionReqState = 1;
    final int initialState = 0;
    final int dirHeaderSendState = 2;
    final int fileHeaderSendState = 3;
    final int fileSendState = 4;
    final int fileFinishedState = 5;
    private boolean isLive = false;
    private int numFiles = 0;
    private int filePointer = 0;
    String request = "May I send?";
    String respServer = "Yes,You can";
    String dirResponse = "Directory created...Please send files";
    String fileHeaderRecvd = "File header received ...Send File";
    String fileReceived = "File Received";
    String dirFailedResponse = "Failed";
    File[] opFileList = null;

    public DirectoryTxr(Socket clientSocket, String srcDir, String dstDir) {

        try {
            this.clientSocket = clientSocket;
            inStream = clientSocket.getInputStream();
            outStream = clientSocket.getOutputStream();
            isLive = true;
            this.srcDir = srcDir;
            this.dstDir = dstDir;
            state = initialState;
            readResponse(); //starting read thread
            sendMessage(request);
            state = permissionReqState;
        } catch (IOException io) {
            io.printStackTrace();
        }


    }

    private void sendMessage(String message) {
        try {
            sendBytes(request.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }


    /**
     * Thread to read response from server
     */
    private void readResponse() {
        Runnable readRunnable = new Runnable() {
            public void run() {
                while (isLive) {
                    try {
                        int num = inStream.read(readBuffer);
                        if (num > 0) {
                            byte[] tempArray = new byte[num];
                            System.arraycopy(readBuffer, 0, tempArray, 0, num);
                            processBytes(tempArray);
                        }
                    } catch (SocketException se) {
                        System.exit(0);
                    } catch (IOException io) {
                        io.printStackTrace();
                        isLive = false;
                    }
                }
            }
        };
        Thread readThread = new Thread(readRunnable);
        readThread.start();

    }

    private void sendDirectoryHeader() {
        File file = new File(srcDir);
        if (file.isDirectory()) {
            try {
                String[] childFiles = file.list();
                numFiles = childFiles.length;
                String dirHeader = "$" + dstDir + "#" + numFiles + "&";
                sendBytes(dirHeader.getBytes("UTF-8"));
            } catch (UnsupportedEncodingException en) {
                en.printStackTrace();
            }
        } else {
            System.out.println(srcDir + " is not a valid directory");
        }
    }


    private void sendFile(String dirName) {
        File file = new File(dirName);

        if (!file.isDirectory()) {
            try {
                int len = (int) file.length();
                int buffSize = len / 8;
                //to avoid the heap limitation
                RandomAccessFile raf = new RandomAccessFile(file, "rw");
                FileChannel channel = raf.getChannel();

                int numRead = 0;
                while (numRead >= 0) {
                    ByteBuffer buf = ByteBuffer.allocate(1024 * 100000);
                    numRead = channel.read(buf);
                    if (numRead > 0) {
                        byte[] array = new byte[numRead];
                        System.arraycopy(buf.array(), 0, array, 0, numRead);
                        sendBytes(array);
                    }
                }
                System.out.println("Finished");

            } catch (IOException io) {
                io.printStackTrace();
            }

        }

    }

    private void sendHeader(String fileName) {
        try {
            File file = new File(fileName);
            if (file.isDirectory())
                return;//avoiding child directories to avoid confusion
            //if want we can sent them recursively
            //with proper state transitions

            String header = "&" + fileName + "#" + file.length() + "*";
            sendHeader(header);

            sendBytes(header.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

    private void sendBytes(byte[] dataBytes) {
        synchronized (clientSocket) {
            if (outStream != null) {
                try {
                    outStream.write(dataBytes);
                    outStream.flush();
                } catch (IOException io) {
                    io.printStackTrace();
                }
            }
        }

    }

    private void processBytes(byte[] data) {
        try {
            String parsedMessage = new String(data, "UTF-8");
            System.out.println(parsedMessage);
            setResponse(parsedMessage);
        } catch (UnsupportedEncodingException u) {
            u.printStackTrace();
        }
    }

    private void setResponse(String message) {
        if (message.trim().equalsIgnoreCase(respServer) && state == permissionReqState) {
            state = dirHeaderSendState;
            sendDirectoryHeader();


        } else if (message.trim().equalsIgnoreCase(dirResponse) && state == dirHeaderSendState) {
            state = fileHeaderSendState;
            if (LocateDirectory()) {
                createAndSendHeader();
            } else {
                System.out.println("Vacant or invalid directory");
            }


        } else if (message.trim().equalsIgnoreCase(fileHeaderRecvd) && state == fileHeaderSendState) {
            state = fileSendState;
            sendFile(opFileList[filePointer].toString());
            state = fileFinishedState;
            filePointer++;

        } else if (message.trim().equalsIgnoreCase(fileReceived) && state == fileFinishedState) {
            if (filePointer < numFiles) {
                createAndSendHeader();
            }
            System.out.println("Successfully sent");

        } else if (message.trim().equalsIgnoreCase(dirFailedResponse)) {
            System.out.println("Going to exit....Error ");
            // System.exit(0);
        } else if (message.trim().equalsIgnoreCase("Thanks")) {
            System.out.println("All files were copied");
        }

    }

    private void closeSocket() {
        try {
            clientSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    private boolean LocateDirectory() {
        boolean status = false;
        File file = new File(srcDir);
        if (file.isDirectory()) {
            opFileList = file.listFiles();
            numFiles = opFileList.length;
            if (numFiles <= 0) {
                System.out.println("No files found");
            } else {
                status = true;
            }

        }
        return status;
    }

    private void createAndSendHeader() {
        File opFile = opFileList[filePointer];
        String header = "&" + opFile.getName() + "#" + opFile.length() + "*";
        try {
            state = fileHeaderSendState;
            sendBytes(header.getBytes("UTF-8"));

        } catch (UnsupportedEncodingException e) {

        }
    }

    private void sendListFiles() {
        createAndSendHeader();

    }
}

[B](ServerMain.java)[/B]

public class ServerMain {

    public ServerMain() {

    }

    public static void main(String[] args) {

        DirectoryRcr dirRcr = new DirectoryRcr();

    }
}

[B](DirectoryRcr.java)[/B]

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;

public class DirectoryRcr {

    String request = "May I send?";
    String respServer = "Yes,You can";
    String dirResponse = "Directory created...Please send files";
    String dirFailedResponse = "Failed";
    String fileHeaderRecvd = "File header received ...Send File";
    String fileReceived = "File Received";
    Socket socket = null;
    OutputStream ioStream = null;
    InputStream inStream = null;
    boolean isLive = false;
    int state = 0;
    final int initialState = 0;
    final int dirHeaderWait = 1;
    final int dirWaitState = 2;
    final int fileHeaderWaitState = 3;
    final int fileContentWaitState = 4;
    final int fileReceiveState = 5;
    final int fileReceivedState = 6;
    final int finalState = 7;
    byte[] readBuffer = new byte[1024 * 100000];
    long fileSize = 0;
    String dir = "";
    FileOutputStream foStream = null;
    int fileCount = 0;
    File dstFile = null;

    public DirectoryRcr() {
        acceptConnection();
    }

    private void acceptConnection() {
        try {
            ServerSocket server = new ServerSocket(3339);
            socket = server.accept();
            isLive = true;
            ioStream = socket.getOutputStream();
            inStream = socket.getInputStream();
            state = initialState;
            startReadThread();

        } catch (IOException io) {
            io.printStackTrace();
        }
    }

    private void startReadThread() {
        Thread readRunnable = new Thread() {
            public void run() {
                while (isLive) {
                    try {
                        int num = inStream.read(readBuffer);
                        if (num > 0) {
                            byte[] tempArray = new byte[num];
                            System.arraycopy(readBuffer, 0, tempArray, 0, num);
                            processBytes(tempArray);
                        }
                        sleep(100);

                    } catch (SocketException s) {

                    } catch (IOException e) {
                        e.printStackTrace();
                    } catch (InterruptedException i) {
                        i.printStackTrace();
                    }
                }
            }
        };
        Thread readThread = new Thread(readRunnable);
        readThread.start();
    }

    private void processBytes(byte[] buff) throws InterruptedException {
        if (state == fileReceiveState || state == fileContentWaitState) {
            //write to file
            if (state == fileContentWaitState)
                state = fileReceiveState;
            fileSize = fileSize - buff.length;
            writeToFile(buff);


            if (fileSize == 0) {
                state = fileReceivedState;
                try {
                    foStream.close();
                } catch (IOException io) {
                    io.printStackTrace();
                }
                System.out.println("Received " + dstFile.getName());
                sendResponse(fileReceived);
                fileCount--;
                if (fileCount != 0) {
                    state = fileHeaderWaitState;
                } else {
                    System.out.println("Finished");
                    state = finalState;
                    sendResponse("Thanks");
                    Thread.sleep(2000);
                    System.exit(0);
                }

                System.out.println("Received");
            }
        } else {
            parseToUTF(buff);
        }

    }

    private void parseToUTF(byte[] data) {
        try {
            String parsedMessage = new String(data, "UTF-8");
            System.out.println(parsedMessage);
            setResponse(parsedMessage);
        } catch (UnsupportedEncodingException u) {
            u.printStackTrace();
        }

    }

    private void setResponse(String message) {
        if (message.trim().equalsIgnoreCase(request) && state == initialState) {
            sendResponse(respServer);
            state = dirHeaderWait;

        } else if (state == dirHeaderWait) {
            if (createDirectory(message)) {
                sendResponse(dirResponse);
                state = fileHeaderWaitState;
            } else {
                sendResponse(dirFailedResponse);
                System.out.println("Error occurred...Going to exit");
                System.exit(0);
            }


        } else if (state == fileHeaderWaitState) {
            createFile(message);
            state = fileContentWaitState;
            sendResponse(fileHeaderRecvd);

        } else if (message.trim().equalsIgnoreCase(dirFailedResponse)) {
            System.out.println("Error occurred ....");
            System.exit(0);
        }

    }

    private void sendResponse(String resp) {
        try {
            sendBytes(resp.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

    private boolean createDirectory(String dirName) {
        boolean status = false;
        dir = dirName.substring(dirName.indexOf("$") + 1, dirName.indexOf("#"));
        fileCount = Integer.parseInt(dirName.substring(dirName.indexOf("#") + 1, dirName.indexOf("&")));
        if (new File(dir).mkdir()) {
            status = true;
            System.out.println("Successfully created directory  " + dirName);
        } else if (new File(dir).mkdirs()) {
            status = true;
            System.out.println("Directories were created " + dirName);

        } else if (new File(dir).exists()) {
            status = true;
            System.out.println("Directory exists" + dirName);
        } else {
            System.out.println("Could not create directory " + dirName);
            status = false;
        }

        return status;
    }

    private void createFile(String fileName) {

        String file = fileName.substring(fileName.indexOf("&") + 1, fileName.indexOf("#"));
        String lengthFile = fileName.substring(fileName.indexOf("#") + 1, fileName.indexOf("*"));
        fileSize = Integer.parseInt(lengthFile);
        dstFile = new File(dir + "/" + file);
        try {
            foStream = new FileOutputStream(dstFile);
            System.out.println("Starting to receive " + dstFile.getName());
        } catch (FileNotFoundException fn) {
            fn.printStackTrace();
        }

    }

    private void writeToFile(byte[] buff) {
        try {
            foStream.write(buff);
        } catch (IOException io) {
            io.printStackTrace();
        }
    }

    private void sendBytes(byte[] dataBytes) {
        synchronized (socket) {
            if (ioStream != null) {
                try {
                    ioStream.write(dataBytes);
                } catch (IOException io) {
                    io.printStackTrace();
                }
            }
        }

    }

}
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