List of usage examples for java.nio ByteBuffer allocateDirect
public static ByteBuffer allocateDirect(int capacity)
From source file:Main.java
public static void main(String[] args) throws Exception { String fromFileName = "from.txt"; String toFileName = "to.txt"; FileChannel in = new FileInputStream(fromFileName).getChannel(); FileChannel out = new FileOutputStream(toFileName).getChannel(); ByteBuffer buff = ByteBuffer.allocateDirect(32 * 1024); while (in.read(buff) > 0) { buff.flip();//from www .j av a 2s .co m out.write(buff); buff.clear(); } in.close(); out.close(); }
From source file:MainClass.java
public static void main(String args[]) { FileOutputStream fileOutputStream; FileChannel fileChannel;//from w w w . j ava 2s . c o m ByteBuffer byteBuffer; try { fileOutputStream = new FileOutputStream("test.txt"); fileChannel = fileOutputStream.getChannel(); byteBuffer = ByteBuffer.allocateDirect(26); for (int i = 0; i < 26; i++) byteBuffer.put((byte) ('A' + i)); byteBuffer.rewind(); fileChannel.write(byteBuffer); fileChannel.close(); fileOutputStream.close(); } catch (IOException exc) { System.out.println(exc); } }
From source file:MainClass.java
public static void main(String[] args) throws Exception { DatagramChannel channel = DatagramChannel.open(); DatagramSocket socket = channel.socket(); SocketAddress address = new InetSocketAddress(9999); socket.bind(address);/* w w w . ja v a 2 s .c om*/ ByteBuffer buffer = ByteBuffer.allocateDirect(65507); while (true) { SocketAddress client = channel.receive(buffer); buffer.flip(); channel.send(buffer, client); buffer.clear(); } }
From source file:Main.java
public static void main(String[] argv) throws Exception { // Create a ByteBuffer using a byte array byte[] bytes = new byte[10]; ByteBuffer buffer = ByteBuffer.wrap(bytes); // Create a non-direct ByteBuffer with a 10 byte capacity // The underlying storage is a byte array. buffer = ByteBuffer.allocate(10); // Create a memory-mapped ByteBuffer with a 10 byte capacity. buffer = ByteBuffer.allocateDirect(10); }
From source file:GetWebPageDemo.java
public static void main(String args[]) throws Exception { String resource, host, file;//w ww. j a v a 2s .c o m int slashPos; resource = "www.java2s.com/index.htm"; slashPos = resource.indexOf('/'); // find host/file separator if (slashPos < 0) { resource = resource + "/"; slashPos = resource.indexOf('/'); } file = resource.substring(slashPos); // isolate host and file parts host = resource.substring(0, slashPos); System.out.println("Host to contact: '" + host + "'"); System.out.println("File to fetch : '" + file + "'"); SocketChannel channel = null; try { Charset charset = Charset.forName("ISO-8859-1"); CharsetDecoder decoder = charset.newDecoder(); CharsetEncoder encoder = charset.newEncoder(); ByteBuffer buffer = ByteBuffer.allocateDirect(1024); CharBuffer charBuffer = CharBuffer.allocate(1024); InetSocketAddress socketAddress = new InetSocketAddress(host, 80); channel = SocketChannel.open(); channel.connect(socketAddress); String request = "GET " + file + " \r\n\r\n"; channel.write(encoder.encode(CharBuffer.wrap(request))); while ((channel.read(buffer)) != -1) { buffer.flip(); decoder.decode(buffer, charBuffer, false); charBuffer.flip(); System.out.println(charBuffer); buffer.clear(); charBuffer.clear(); } } catch (UnknownHostException e) { System.err.println(e); } catch (IOException e) { System.err.println(e); } finally { if (channel != null) { try { channel.close(); } catch (IOException ignored) { } } } System.out.println("\nDone."); }
From source file:GetWebPageApp.java
public static void main(String args[]) throws Exception { String resource, host, file;//from w w w. j av a2s. c o m int slashPos; resource = "www.java2s.com/index.htm"; // skip HTTP:// slashPos = resource.indexOf('/'); // find host/file separator if (slashPos < 0) { resource = resource + "/"; slashPos = resource.indexOf('/'); } file = resource.substring(slashPos); // isolate host and file parts host = resource.substring(0, slashPos); System.out.println("Host to contact: '" + host + "'"); System.out.println("File to fetch : '" + file + "'"); SocketChannel channel = null; try { Charset charset = Charset.forName("ISO-8859-1"); CharsetDecoder decoder = charset.newDecoder(); CharsetEncoder encoder = charset.newEncoder(); ByteBuffer buffer = ByteBuffer.allocateDirect(1024); CharBuffer charBuffer = CharBuffer.allocate(1024); InetSocketAddress socketAddress = new InetSocketAddress(host, 80); channel = SocketChannel.open(); channel.configureBlocking(false); channel.connect(socketAddress); selector = Selector.open(); channel.register(selector, SelectionKey.OP_CONNECT | SelectionKey.OP_READ); while (selector.select(500) > 0) { Set readyKeys = selector.selectedKeys(); try { Iterator readyItor = readyKeys.iterator(); while (readyItor.hasNext()) { SelectionKey key = (SelectionKey) readyItor.next(); readyItor.remove(); SocketChannel keyChannel = (SocketChannel) key.channel(); if (key.isConnectable()) { if (keyChannel.isConnectionPending()) { keyChannel.finishConnect(); } String request = "GET " + file + " \r\n\r\n"; keyChannel.write(encoder.encode(CharBuffer.wrap(request))); } else if (key.isReadable()) { keyChannel.read(buffer); buffer.flip(); decoder.decode(buffer, charBuffer, false); charBuffer.flip(); System.out.print(charBuffer); buffer.clear(); charBuffer.clear(); } else { System.err.println("Unknown key"); } } } catch (ConcurrentModificationException e) { } } } catch (UnknownHostException e) { System.err.println(e); } catch (IOException e) { System.err.println(e); } finally { if (channel != null) { try { channel.close(); } catch (IOException ignored) { } } } System.out.println("\nDone."); }
From source file:org.apache.commons.crypto.examples.CipherByteBufferExample.java
public static void main(String[] args) throws Exception { final SecretKeySpec key = new SecretKeySpec(getUTF8Bytes("1234567890123456"), "AES"); final IvParameterSpec iv = new IvParameterSpec(getUTF8Bytes("1234567890123456")); Properties properties = new Properties(); //Creates a CryptoCipher instance with the transformation and properties. final String transform = "AES/CBC/PKCS5Padding"; final ByteBuffer outBuffer; final int bufferSize = 1024; final int updateBytes; final int finalBytes; try (CryptoCipher encipher = Utils.getCipherInstance(transform, properties)) { ByteBuffer inBuffer = ByteBuffer.allocateDirect(bufferSize); outBuffer = ByteBuffer.allocateDirect(bufferSize); inBuffer.put(getUTF8Bytes("hello world!")); inBuffer.flip(); // ready for the cipher to read it // Show the data is there System.out.println("inBuffer=" + asString(inBuffer)); // Initializes the cipher with ENCRYPT_MODE,key and iv. encipher.init(Cipher.ENCRYPT_MODE, key, iv); // Continues a multiple-part encryption/decryption operation for byte buffer. updateBytes = encipher.update(inBuffer, outBuffer); System.out.println(updateBytes); // We should call do final at the end of encryption/decryption. finalBytes = encipher.doFinal(inBuffer, outBuffer); System.out.println(finalBytes); }/*w ww .ja v a2 s . c o m*/ outBuffer.flip(); // ready for use as decrypt byte[] encoded = new byte[updateBytes + finalBytes]; outBuffer.duplicate().get(encoded); System.out.println(Arrays.toString(encoded)); // Now reverse the process try (CryptoCipher decipher = Utils.getCipherInstance(transform, properties)) { decipher.init(Cipher.DECRYPT_MODE, key, iv); ByteBuffer decoded = ByteBuffer.allocateDirect(bufferSize); decipher.update(outBuffer, decoded); decipher.doFinal(outBuffer, decoded); decoded.flip(); // ready for use System.out.println("decoded=" + asString(decoded)); } }
From source file:PrintServiceWebInterface.java
public static void main(String[] args) throws IOException { // Get the character encoders and decoders we'll need Charset charset = Charset.forName("ISO-8859-1"); CharsetEncoder encoder = charset.newEncoder(); // The HTTP headers we send back to the client are fixed String headers = "HTTP/1.1 200 OK\r\n" + "Content-type: text/html\r\n" + "Connection: close\r\n" + "\r\n"; // We'll use two buffers in our response. One holds the fixed // headers, and the other holds the variable body of the response. ByteBuffer[] buffers = new ByteBuffer[2]; buffers[0] = encoder.encode(CharBuffer.wrap(headers)); ByteBuffer body = ByteBuffer.allocateDirect(16 * 1024); buffers[1] = body;/* ww w . j a va 2s . c om*/ // Find all available PrintService objects to describe PrintService[] services = PrintServiceLookup.lookupPrintServices(null, null); // All of the channels we use in this code will be in non-blocking // mode. So we create a Selector object that will block while // monitoring all of the channels and will only stop blocking when // one or more of the channels is ready for I/O of some sort. Selector selector = Selector.open(); // Create a new ServerSocketChannel, and bind it to port 8000. // Note that we have to do this using the underlying ServerSocket. ServerSocketChannel server = ServerSocketChannel.open(); server.socket().bind(new java.net.InetSocketAddress(8000)); // Put the ServerSocketChannel into non-blocking mode server.configureBlocking(false); // Now register the channel with the Selector. The SelectionKey // represents the registration of this channel with this Selector. SelectionKey serverkey = server.register(selector, SelectionKey.OP_ACCEPT); for (;;) { // The main server loop. The server runs forever. // This call blocks until there is activity on one of the // registered channels. This is the key method in non-blocking I/O. selector.select(); // Get a java.util.Set containing the SelectionKey objects for // all channels that are ready for I/O. Set keys = selector.selectedKeys(); // Use a java.util.Iterator to loop through the selected keys for (Iterator i = keys.iterator(); i.hasNext();) { // Get the next SelectionKey in the set, and then remove it // from the set. It must be removed explicitly, or it will // be returned again by the next call to select(). SelectionKey key = (SelectionKey) i.next(); i.remove(); // Check whether this key is the SelectionKey we got when // we registered the ServerSocketChannel. if (key == serverkey) { // Activity on the ServerSocketChannel means a client // is trying to connect to the server. if (key.isAcceptable()) { // Accept the client connection, and obtain a // SocketChannel to communicate with the client. SocketChannel client = server.accept(); // Make sure we actually got a connection if (client == null) continue; // Put the client channel in non-blocking mode. client.configureBlocking(false); // Now register the client channel with the Selector, // specifying that we'd like to know when there is // data ready to read on the channel. SelectionKey clientkey = client.register(selector, SelectionKey.OP_READ); } } else { // If the key we got from the Set of keys is not the // ServerSocketChannel key, then it must be a key // representing one of the client connections. // Get the channel from the key. SocketChannel client = (SocketChannel) key.channel(); // If we got here, it should mean that there is data to // be read from the channel, but we double-check here. if (!key.isReadable()) continue; // Now read bytes from the client. We assume that // we get all the client's bytes in one read operation client.read(body); // The data we read should be some kind of HTTP GET // request. We don't bother checking it however since // there is only one page of data we know how to return. body.clear(); // Build an HTML document as our reponse. // The body of the document contains PrintService details StringBuffer response = new StringBuffer(); response.append( "<html><head><title>Printer Status</title></head>" + "<body><h1>Printer Status</h1>"); for (int s = 0; s < services.length; s++) { PrintService service = services[s]; response.append("<h2>").append(service.getName()).append("</h2><table>"); Attribute[] attrs = service.getAttributes().toArray(); for (int a = 0; a < attrs.length; a++) { Attribute attr = attrs[a]; response.append("<tr><td>").append(attr.getName()).append("</td><td>").append(attr) .append("</tr>"); } response.append("</table>"); } response.append("</body></html>\r\n"); // Encode the response into the body ByteBuffer encoder.reset(); encoder.encode(CharBuffer.wrap(response), body, true); encoder.flush(body); body.flip(); // Prepare the body buffer to be drained // While there are bytes left to write while (body.hasRemaining()) { // Write both header and body buffers client.write(buffers); } buffers[0].flip(); // Prepare header buffer for next write body.clear(); // Prepare body buffer for next read // Once we've sent our response, we have no more interest // in the client channel or its SelectionKey client.close(); // Close the channel. key.cancel(); // Tell Selector to stop monitoring it. } } } }
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 w w w . ja v a 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 ByteBuffer makeByteBuffer(byte[] i_arr) { ByteBuffer bb = ByteBuffer.allocateDirect(i_arr.length); bb.put(i_arr);//from w w w . j av a 2 s . co m bb.position(0); return bb; }