Example usage for java.nio.channels WritableByteChannel write

List of usage examples for java.nio.channels WritableByteChannel write

Introduction

In this page you can find the example usage for java.nio.channels WritableByteChannel write.

Prototype

public int write(ByteBuffer src) throws IOException;

Source Link

Document

Writes a sequence of bytes to this channel from the given buffer.

Usage

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    int port = 19;

    SocketAddress address = new InetSocketAddress("127.0.0.1", port);
    SocketChannel client = SocketChannel.open(address);

    ByteBuffer buffer = ByteBuffer.allocate(74);
    WritableByteChannel out = Channels.newChannel(System.out);

    while (client.read(buffer) != -1) {
        buffer.flip();//www  . j  av a 2 s.c  om
        out.write(buffer);
        buffer.clear();
    }
}

From source file:Main.java

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

    FileInputStream fin = new FileInputStream(args[0]);
    GZIPInputStream gzin = new GZIPInputStream(fin);
    ReadableByteChannel in = Channels.newChannel(gzin);

    WritableByteChannel out = Channels.newChannel(System.out);
    ByteBuffer buffer = ByteBuffer.allocate(65536);
    while (in.read(buffer) != -1) {
        buffer.flip();/*ww w .j a  va 2s .c  om*/
        out.write(buffer);
        buffer.clear();
    }
}

From source file:HttpGet.java

public static void main(String[] args) {
    SocketChannel server = null; // Channel for reading from server
    FileOutputStream outputStream = null; // Stream to destination file
    WritableByteChannel destination; // Channel to write to it

    try { // Exception handling and channel closing code follows this block

        // Parse the URL. Note we use the new java.net.URI, not URL here.
        URI uri = new URI(args[0]);

        // Now query and verify the various parts of the URI
        String scheme = uri.getScheme();
        if (scheme == null || !scheme.equals("http"))
            throw new IllegalArgumentException("Must use 'http:' protocol");

        String hostname = uri.getHost();

        int port = uri.getPort();
        if (port == -1)
            port = 80; // Use default port if none specified

        String path = uri.getRawPath();
        if (path == null || path.length() == 0)
            path = "/";

        String query = uri.getRawQuery();
        query = (query == null) ? "" : '?' + query;

        // Combine the hostname and port into a single address object.
        // java.net.SocketAddress and InetSocketAddress are new in Java 1.4
        SocketAddress serverAddress = new InetSocketAddress(hostname, port);

        // Open a SocketChannel to the server
        server = SocketChannel.open(serverAddress);

        // Put together the HTTP request we'll send to the server.
        String request = "GET " + path + query + " HTTP/1.1\r\n" + // The request
                "Host: " + hostname + "\r\n" + // Required in HTTP 1.1
                "Connection: close\r\n" + // Don't keep connection open
                "User-Agent: " + HttpGet.class.getName() + "\r\n" + "\r\n"; // Blank
                                                                            // line
                                                                            // indicates
                                                                            // end of
                                                                            // request
                                                                            // headers

        // Now wrap a CharBuffer around that request string
        CharBuffer requestChars = CharBuffer.wrap(request);

        // Get a Charset object to encode the char buffer into bytes
        Charset charset = Charset.forName("ISO-8859-1");

        // Use the charset to encode the request into a byte buffer
        ByteBuffer requestBytes = charset.encode(requestChars);

        // Finally, we can send this HTTP request to the server.
        server.write(requestBytes);//from www  . j  a  va 2 s. c  o  m

        // Set up an output channel to send the output to.
        if (args.length > 1) { // Use a specified filename
            outputStream = new FileOutputStream(args[1]);
            destination = outputStream.getChannel();
        } else
            // Or wrap a channel around standard out
            destination = Channels.newChannel(System.out);

        // Allocate a 32 Kilobyte byte buffer for reading the response.
        // Hopefully we'll get a low-level "direct" buffer
        ByteBuffer data = ByteBuffer.allocateDirect(32 * 1024);

        // Have we discarded the HTTP response headers yet?
        boolean skippedHeaders = false;
        // The code sent by the server
        int responseCode = -1;

        // Now loop, reading data from the server channel and writing it
        // to the destination channel until the server indicates that it
        // has no more data.
        while (server.read(data) != -1) { // Read data, and check for end
            data.flip(); // Prepare to extract data from buffer

            // All HTTP reponses begin with a set of HTTP headers, which
            // we need to discard. The headers end with the string
            // "\r\n\r\n", or the bytes 13,10,13,10. If we haven't already
            // skipped them then do so now.
            if (!skippedHeaders) {
                // First, though, read the HTTP response code.
                // Assume that we get the complete first line of the
                // response when the first read() call returns. Assume also
                // that the first 9 bytes are the ASCII characters
                // "HTTP/1.1 ", and that the response code is the ASCII
                // characters in the following three bytes.
                if (responseCode == -1) {
                    responseCode = 100 * (data.get(9) - '0') + 10 * (data.get(10) - '0')
                            + 1 * (data.get(11) - '0');

                    // If there was an error, report it and quit
                    // Note that we do not handle redirect responses.
                    if (responseCode < 200 || responseCode >= 300) {
                        System.err.println("HTTP Error: " + responseCode);
                        System.exit(1);
                    }
                }

                // Now skip the rest of the headers.
                try {
                    for (;;) {
                        if ((data.get() == 13) && (data.get() == 10) && (data.get() == 13)
                                && (data.get() == 10)) {
                            skippedHeaders = true;
                            break;
                        }
                    }
                } catch (BufferUnderflowException e) {
                    // If we arrive here, it means we reached the end of
                    // the buffer and didn't find the end of the headers.
                    // There is a chance that the last 1, 2, or 3 bytes in
                    // the buffer were the beginning of the \r\n\r\n
                    // sequence, so back up a bit.
                    data.position(data.position() - 3);
                    // Now discard the headers we have read
                    data.compact();
                    // And go read more data from the server.
                    continue;
                }
            }

            // Write the data out; drain the buffer fully.
            while (data.hasRemaining())
                destination.write(data);

            // Now that the buffer is drained, put it into fill mode
            // in preparation for reading more data into it.
            data.clear(); // data.compact() also works here
        }
    } catch (Exception e) { // Report any errors that arise
        System.err.println(e);
        System.err.println("Usage: java HttpGet <URL> [<filename>]");
    } finally { // Close the channels and output file stream, if needed
        try {
            if (server != null && server.isOpen())
                server.close();
            if (outputStream != null)
                outputStream.close();
        } catch (IOException e) {
        }
    }
}

From source file:Main.java

public static void writeFully(final WritableByteChannel channel, final ByteBuffer buf) throws IOException {
    do {//from w ww  .j a  v a2 s  .c  o  m
        int written = channel.write(buf);
        if (written < 0) {
            throw new EOFException();
        }
    } while (buf.hasRemaining());
}

From source file:com.eatnumber1.util.io.IOUtils.java

public static void write(@NotNull WritableByteChannel channel, @NotNull ByteBuffer src, int expected)
        throws IOException {
    if (channel.write(src) != expected)
        throw new IOException("Did not write expected amount of data");
}

From source file:Main.java

public static void copy(ReadableByteChannel src, WritableByteChannel dest) throws IOException {
    ByteBuffer buffer = ByteBuffer.allocateDirect(CAPACITY);
    while (src.read(buffer) != -1) {
        buffer.flip();//from  w w  w.j  a v a  2  s . c  o m
        dest.write(buffer);
        buffer.compact();
    }

    buffer.flip();

    while (buffer.hasRemaining()) {
        dest.write(buffer);
    }
}

From source file:Main.java

public static void transfer(ReadableByteChannel in, WritableByteChannel out) throws IOException {
    ByteBuffer buffer = ByteBuffer.allocate(4096);
    while (in.read(buffer) != -1) {
        buffer.flip();/*from   ww w . j  a v  a  2  s .  co  m*/
        while (buffer.hasRemaining()) {
            out.write(buffer);
        }
        buffer.clear();
    }
}

From source file:IOUtilities.java

/**
 * Copy ALL available data from one stream into another
 * @param in//from w  ww.  j a v a2s.  c o m
 * @param out
 * @throws IOException
 */
public static void copy(InputStream in, OutputStream out) throws IOException {
    ReadableByteChannel source = Channels.newChannel(in);
    WritableByteChannel target = Channels.newChannel(out);

    ByteBuffer buffer = ByteBuffer.allocate(16 * 1024);
    while (source.read(buffer) != -1) {
        buffer.flip(); // Prepare the buffer to be drained
        while (buffer.hasRemaining()) {
            target.write(buffer);
        }
        buffer.clear(); // Empty buffer to get ready for filling
    }

    source.close();
    target.close();

}

From source file:com.thinkberg.webdav.Util.java

public static long copyStream(final InputStream is, final OutputStream os) throws IOException {
    ReadableByteChannel rbc = Channels.newChannel(is);
    WritableByteChannel wbc = Channels.newChannel(os);

    int bytesWritten = 0;
    final ByteBuffer buffer = ByteBuffer.allocateDirect(16 * 1024);
    while (rbc.read(buffer) != -1) {
        buffer.flip();//from   ww w . ja va 2s  .c om
        bytesWritten += wbc.write(buffer);
        buffer.compact();
    }
    buffer.flip();
    while (buffer.hasRemaining()) {
        bytesWritten += wbc.write(buffer);
    }

    rbc.close();
    wbc.close();

    return bytesWritten;
}

From source file:Main.java

public static void fastChannelCopy(final ReadableByteChannel src, final WritableByteChannel dest)
        throws IOException {
    final ByteBuffer buffer = ByteBuffer.allocateDirect(16 * 1024);
    while (src.read(buffer) != -1) {
        // prepare the buffer to be drained
        buffer.flip();/* w  ww  .j  av a  2s  . c o m*/
        // write to the channel, may block
        dest.write(buffer);
        // If partial transfer, shift remainder down
        // If buffer is empty, same as doing recycle()
        buffer.compact();
    }
    // EOF will leave buffer in fill state
    buffer.flip();
    // make sure the buffer is fully drained.
    while (buffer.hasRemaining()) {
        dest.write(buffer);
    }
}