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tftp.javaAPI DocApache Commons NET 1.4.1 API8144Sat Dec 03 10:05:48 GMT 2005examples

tftp

public final class tftp extends Object
This is an example of a simple Java tftp client using NetComponents. Notice how all of the code is really just argument processing and error handling.

Usage: tftp [options] hostname localfile remotefile hostname - The name of the remote host localfile - The name of the local file to send or the name to use for the received file remotefile - The name of the remote file to receive or the name for the remote server to use to name the local file being sent. options: (The default is to assume -r -b) -s Send a local file -r Receive a remote file -a Use ASCII transfer mode -b Use binary transfer mode

Fields Summary
static final String
USAGE
Constructors Summary
Methods Summary
public static final voidmain(java.lang.String[] args)


         
    
        boolean receiveFile = true, closed;
        int transferMode = TFTP.BINARY_MODE, argc;
        String arg, hostname, localFilename, remoteFilename;
        TFTPClient tftp;

        // Parse options
        for (argc = 0; argc < args.length; argc++)
        {
            arg = args[argc];
            if (arg.startsWith("-"))
            {
                if (arg.equals("-r"))
                    receiveFile = true;
                else if (arg.equals("-s"))
                    receiveFile = false;
                else if (arg.equals("-a"))
                    transferMode = TFTP.ASCII_MODE;
                else if (arg.equals("-b"))
                    transferMode = TFTP.BINARY_MODE;
                else
                {
                    System.err.println("Error: unrecognized option.");
                    System.err.print(USAGE);
                    System.exit(1);
                }
            }
            else
                break;
        }

        // Make sure there are enough arguments
        if (args.length - argc != 3)
        {
            System.err.println("Error: invalid number of arguments.");
            System.err.print(USAGE);
            System.exit(1);
        }

        // Get host and file arguments
        hostname = args[argc];
        localFilename = args[argc + 1];
        remoteFilename = args[argc + 2];

        // Create our TFTP instance to handle the file transfer.
        tftp = new TFTPClient();

        // We want to timeout if a response takes longer than 60 seconds
        tftp.setDefaultTimeout(60000);

        // Open local socket
        try
        {
            tftp.open();
        }
        catch (SocketException e)
        {
            System.err.println("Error: could not open local UDP socket.");
            System.err.println(e.getMessage());
            System.exit(1);
        }

        // We haven't closed the local file yet.
        closed = false;

        // If we're receiving a file, receive, otherwise send.
        if (receiveFile)
        {
            FileOutputStream output = null;
            File file;

            file = new File(localFilename);

            // If file exists, don't overwrite it.
            if (file.exists())
            {
                System.err.println("Error: " + localFilename + " already exists.");
                System.exit(1);
            }

            // Try to open local file for writing
            try
            {
                output = new FileOutputStream(file);
            }
            catch (IOException e)
            {
                tftp.close();
                System.err.println("Error: could not open local file for writing.");
                System.err.println(e.getMessage());
                System.exit(1);
            }

            // Try to receive remote file via TFTP
            try
            {
                tftp.receiveFile(remoteFilename, transferMode, output, hostname);
            }
            catch (UnknownHostException e)
            {
                System.err.println("Error: could not resolve hostname.");
                System.err.println(e.getMessage());
                System.exit(1);
            }
            catch (IOException e)
            {
                System.err.println(
                    "Error: I/O exception occurred while receiving file.");
                System.err.println(e.getMessage());
                System.exit(1);
            }
            finally
            {
                // Close local socket and output file
                tftp.close();
                try
                {
                    output.close();
                    closed = true;
                }
                catch (IOException e)
                {
                    closed = false;
                    System.err.println("Error: error closing file.");
                    System.err.println(e.getMessage());
                }
            }

            if (!closed)
                System.exit(1);

        }
        else
        {
            // We're sending a file
            FileInputStream input = null;

            // Try to open local file for reading
            try
            {
                input = new FileInputStream(localFilename);
            }
            catch (IOException e)
            {
                tftp.close();
                System.err.println("Error: could not open local file for reading.");
                System.err.println(e.getMessage());
                System.exit(1);
            }

            // Try to send local file via TFTP
            try
            {
                tftp.sendFile(remoteFilename, transferMode, input, hostname);
            }
            catch (UnknownHostException e)
            {
                System.err.println("Error: could not resolve hostname.");
                System.err.println(e.getMessage());
                System.exit(1);
            }
            catch (IOException e)
            {
                System.err.println(
                    "Error: I/O exception occurred while sending file.");
                System.err.println(e.getMessage());
                System.exit(1);
            }
            finally
            {
                // Close local socket and input file
                tftp.close();
                try
                {
                    input.close();
                    closed = true;
                }
                catch (IOException e)
                {
                    closed = false;
                    System.err.println("Error: error closing file.");
                    System.err.println(e.getMessage());
                }
            }

            if (!closed)
                System.exit(1);

        }