Example usage for java.nio.channels Channels newChannel

List of usage examples for java.nio.channels Channels newChannel

Introduction

In this page you can find the example usage for java.nio.channels Channels newChannel.

Prototype

public static WritableByteChannel newChannel(OutputStream out) 

Source Link

Document

Constructs a channel that writes bytes to the given stream.

Usage

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();/* w ww.j  a v  a2s  . c  om*/
        out.write(buffer);
        buffer.clear();
    }
}

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();//from w ww .  ja  va 2 s . c  o m
        out.write(buffer);
        buffer.clear();
    }
}

From source file:Main.java

public static void main(String[] args) throws IOException {
    // Open file streams and get channels for them.
    ReadableByteChannel in = new FileInputStream(args[0]).getChannel();
    WritableByteChannel out;//from  w  w w.j  a  v a  2 s  .  co m
    if (args.length > 1)
        out = new FileOutputStream(args[1]).getChannel();
    else
        out = Channels.newChannel(System.out);

    // Do the copy
    copy(in, out);

    // Exception handling and stream-closing code has been omitted.
}

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   ww w .j  a v a2 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:eu.ensure.aging.AgingSimulator.java

public static void main(String[] args) {

    Options options = new Options();
    options.addOption("n", "flip-bit-in-name", true, "Flip bit in first byte of name of first file");
    options.addOption("u", "flip-bit-in-uname", true, "Flip bit in first byte of username of first file");
    options.addOption("c", "update-checksum", true, "Update header checksum (after prior bit flips)");

    Properties properties = new Properties();
    CommandLineParser parser = new PosixParser();
    try {//from   w  w w .  ja  v a2  s . c o m
        CommandLine line = parser.parse(options, args);

        //
        if (line.hasOption("flip-bit-in-name")) {
            properties.put("flip-bit-in-name", line.getOptionValue("flip-bit-in-name"));
        } else {
            // On by default (if not explicitly de-activated above)
            properties.put("flip-bit-in-name", "true");
        }

        //
        if (line.hasOption("flip-bit-in-uname")) {
            properties.put("flip-bit-in-uname", line.getOptionValue("flip-bit-in-uname"));
        } else {
            properties.put("flip-bit-in-uname", "false");
        }

        //
        if (line.hasOption("update-checksum")) {
            properties.put("update-checksum", line.getOptionValue("update-checksum"));
        } else {
            properties.put("update-checksum", "false");
        }

        String[] fileArgs = line.getArgs();

        if (fileArgs.length < 1) {
            printHelp(options, System.err);
            System.exit(1);
        }

        String srcPath = fileArgs[0];

        File srcAIP = new File(srcPath);
        if (!srcAIP.exists()) {
            String info = "The source path does not locate a file: " + srcPath;
            System.err.println(info);
            System.exit(1);
        }

        if (srcAIP.isDirectory()) {
            String info = "The source path locates a directory, not a file: " + srcPath;
            System.err.println(info);
            System.exit(1);
        }

        if (!srcAIP.canRead()) {
            String info = "Cannot read source file: " + srcPath;
            System.err.println(info);
            System.exit(1);
        }

        boolean doReplace = false;
        File destAIP = null;

        if (fileArgs.length > 1) {
            String destPath = fileArgs[1];
            destAIP = new File(destPath);

            if (destAIP.exists()) {
                String info = "The destination path locates an existing file: " + destPath;
                System.err.println(info);
                System.exit(1);
            }
        } else {
            doReplace = true;
            try {
                destAIP = File.createTempFile("tmp-aged-aip-", ".tar");
            } catch (IOException ioe) {
                String info = "Failed to create temporary file: ";
                info += ioe.getMessage();
                System.err.println(info);
                System.exit(1);
            }
        }

        String info = "Age simulation\n";
        info += "  Reading from " + srcAIP.getName() + "\n";
        if (doReplace) {
            info += "  and replacing it's content";
        } else {
            info += "  Writing to " + destAIP.getName();
        }
        System.out.println(info);

        //
        InputStream is = null;
        OutputStream os = null;
        try {
            is = new BufferedInputStream(new FileInputStream(srcAIP));
            os = new BufferedOutputStream(new FileOutputStream(destAIP));

            simulateAging(srcAIP.getName(), is, os, properties);

        } catch (FileNotFoundException fnfe) {
            info = "Could not locate file: " + fnfe.getMessage();
            System.err.println(info);
        } finally {
            try {
                if (null != os)
                    os.close();
                if (null != is)
                    is.close();
            } catch (IOException ignore) {
            }
        }

        //
        if (doReplace) {
            File renamedOriginal = new File(srcAIP.getName() + "-backup");
            srcAIP.renameTo(renamedOriginal);

            ReadableByteChannel rbc = null;
            WritableByteChannel wbc = null;
            try {
                rbc = Channels.newChannel(new FileInputStream(destAIP));
                wbc = Channels.newChannel(new FileOutputStream(srcAIP));
                FileIO.fastChannelCopy(rbc, wbc);
            } catch (FileNotFoundException fnfe) {
                info = "Could not locate temporary output file: " + fnfe.getMessage();
                System.err.println(info);
            } catch (IOException ioe) {
                info = "Could not copy temporary output file over original AIP: " + ioe.getMessage();
                System.err.println(info);
            } finally {
                try {
                    if (null != wbc)
                        wbc.close();
                    if (null != rbc)
                        rbc.close();

                    destAIP.delete();
                } catch (IOException ignore) {
                }
            }
        }
    } catch (ParseException pe) {
        String info = "Failed to parse command line: " + pe.getMessage();
        System.err.println(info);
        printHelp(options, System.err);
        System.exit(1);
    }
}

From source file:Main.java

public static ReadableByteChannel getChannel(InputStream inputStream) {
    return (inputStream != null) ? Channels.newChannel(inputStream) : null;
}

From source file:Main.java

public static void copyStream(InputStream input, OutputStream output) throws IOException {
    final ReadableByteChannel inputChannel = Channels.newChannel(input);
    final WritableByteChannel outputChannel = Channels.newChannel(output);
    // copy the channels
    fastChannelCopy(inputChannel, outputChannel);
}

From source file:Main.java

public static WritableByteChannel getChannel(OutputStream outputStream) {
    return (outputStream != null) ? Channels.newChannel(outputStream) : null;
}

From source file:IOUtilities.java

/**
 * Copy ALL available data from one stream into another
 * @param in/*from   www . j a  v  a  2  s  .  c  om*/
 * @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:Main.java

public static void writeUrlToFileNIO(String urlToRead, String folderToWrite, String fileName)
        throws MalformedURLException, IOException {
    URL urlIn = new URL(urlToRead);
    File folderOut = Paths.get(folderToWrite).toFile();
    if (!(folderOut.exists() || folderOut.mkdirs())) {
        throw new RuntimeException("could not create folder " + folderToWrite);
    }/* w w  w . j a v a  2s .  com*/
    Path pathOut = Paths.get(folderToWrite, fileName);
    try (ReadableByteChannel in = Channels.newChannel(new BufferedInputStream(urlIn.openStream()));
            WritableByteChannel out = Files.newByteChannel(pathOut, CREATE, WRITE);) {
        transfer(in, out);
    }
}