List of usage examples for java.nio CharBuffer wrap
public static CharBuffer wrap(CharSequence chseq)
From source file:GetWebPageDemo.java
public static void main(String args[]) throws Exception { String resource, host, file;/* w ww . ja va 2 s. 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: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;//from ww w .j av a 2s .com // 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:SimpleDaytimeServer.java
public static void main(String args[]) throws java.io.IOException { // RFC867 specifies port 13 for this service. On Unix platforms, // you need to be running as root to use that port, so we allow // this service to use other ports for testing. int port = 13; if (args.length > 0) port = Integer.parseInt(args[0]); // Create a channel to listen for connections on. ServerSocketChannel server = ServerSocketChannel.open(); // Bind the channel to a local port. Note that we do this by obtaining // the underlying java.net.ServerSocket and binding that socket. server.socket().bind(new InetSocketAddress(port)); // Get an encoder for converting strings to bytes CharsetEncoder encoder = Charset.forName("US-ASCII").newEncoder(); for (;;) { // Loop forever, processing client connections // Wait for a client to connect SocketChannel client = server.accept(); // Build response string, wrap, and encode to bytes String date = new java.util.Date().toString() + "\r\n"; ByteBuffer response = encoder.encode(CharBuffer.wrap(date)); // Send the response to the client and disconnect. client.write(response);// www. java 2 s. c o m client.close(); } }
From source file:MainClass.java
public static void main(String[] args) throws IOException { Charset charset = Charset.forName("ISO-8859-1"); CharsetEncoder encoder = charset.newEncoder(); CharsetDecoder decoder = charset.newDecoder(); ByteBuffer buffer = ByteBuffer.allocate(512); Selector selector = Selector.open(); ServerSocketChannel server = ServerSocketChannel.open(); server.socket().bind(new java.net.InetSocketAddress(8000)); server.configureBlocking(false);/*from w ww . j a v a 2s . c o m*/ SelectionKey serverkey = server.register(selector, SelectionKey.OP_ACCEPT); for (;;) { selector.select(); Set keys = selector.selectedKeys(); for (Iterator i = keys.iterator(); i.hasNext();) { SelectionKey key = (SelectionKey) i.next(); i.remove(); if (key == serverkey) { if (key.isAcceptable()) { SocketChannel client = server.accept(); client.configureBlocking(false); SelectionKey clientkey = client.register(selector, SelectionKey.OP_READ); clientkey.attach(new Integer(0)); } } else { SocketChannel client = (SocketChannel) key.channel(); if (!key.isReadable()) continue; int bytesread = client.read(buffer); if (bytesread == -1) { key.cancel(); client.close(); continue; } buffer.flip(); String request = decoder.decode(buffer).toString(); buffer.clear(); if (request.trim().equals("quit")) { client.write(encoder.encode(CharBuffer.wrap("Bye."))); key.cancel(); client.close(); } else { int num = ((Integer) key.attachment()).intValue(); String response = num + ": " + request.toUpperCase(); client.write(encoder.encode(CharBuffer.wrap(response))); key.attach(new Integer(num + 1)); } } } } }
From source file:GetWebPageApp.java
public static void main(String args[]) throws Exception { String resource, host, file;//from w ww . jav a2 s .c om 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: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);/* ww w . j a va2s . c om*/ // 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:DaytimeServer.java
public static void main(String args[]) { try { // Handle startup exceptions at the end of this block // Get an encoder for converting strings to bytes CharsetEncoder encoder = Charset.forName("US-ASCII").newEncoder(); // Allow an alternative port for testing with non-root accounts int port = 13; // RFC867 specifies this port. if (args.length > 0) port = Integer.parseInt(args[0]); // The port we'll listen on SocketAddress localport = new InetSocketAddress(port); // Create and bind a tcp channel to listen for connections on. ServerSocketChannel tcpserver = ServerSocketChannel.open(); tcpserver.socket().bind(localport); // Also create and bind a DatagramChannel to listen on. DatagramChannel udpserver = DatagramChannel.open(); udpserver.socket().bind(localport); // Specify non-blocking mode for both channels, since our // Selector object will be doing the blocking for us. tcpserver.configureBlocking(false); udpserver.configureBlocking(false); // The Selector object is what allows us to block while waiting // for activity on either of the two channels. Selector selector = Selector.open(); // Register the channels with the selector, and specify what // conditions (a connection ready to accept, a datagram ready // to read) we'd like the Selector to wake up for. // These methods return SelectionKey objects, which we don't // need to retain in this example. tcpserver.register(selector, SelectionKey.OP_ACCEPT); udpserver.register(selector, SelectionKey.OP_READ); // This is an empty byte buffer to receive emtpy datagrams with. // If a datagram overflows the receive buffer size, the extra bytes // are automatically discarded, so we don't have to worry about // buffer overflow attacks here. ByteBuffer receiveBuffer = ByteBuffer.allocate(0); // Now loop forever, processing client connections for (;;) { try { // Handle per-connection problems below // Wait for a client to connect selector.select();//w w w . j a v a 2 s.co m // If we get here, a client has probably connected, so // put our response into a ByteBuffer. String date = new java.util.Date().toString() + "\r\n"; ByteBuffer response = encoder.encode(CharBuffer.wrap(date)); // Get the SelectionKey objects for the channels that have // activity on them. These are the keys returned by the // register() methods above. They are returned in a // java.util.Set. Set keys = selector.selectedKeys(); // Iterate through the Set of keys. for (Iterator i = keys.iterator(); i.hasNext();) { // Get a key from the set, and remove it from the set SelectionKey key = (SelectionKey) i.next(); i.remove(); // Get the channel associated with the key Channel c = (Channel) key.channel(); // Now test the key and the channel to find out // whether something happend on the TCP or UDP channel if (key.isAcceptable() && c == tcpserver) { // A client has attempted to connect via TCP. // Accept the connection now. SocketChannel client = tcpserver.accept(); // If we accepted the connection successfully, // the send our respone back to the client. if (client != null) { client.write(response); // send respone client.close(); // close connection } } else if (key.isReadable() && c == udpserver) { // A UDP datagram is waiting. Receive it now, // noting the address it was sent from. SocketAddress clientAddress = udpserver.receive(receiveBuffer); // If we got the datagram successfully, send // the date and time in a response packet. if (clientAddress != null) udpserver.send(response, clientAddress); } } } catch (java.io.IOException e) { // This is a (hopefully transient) problem with a single // connection: we log the error, but continue running. // We use our classname for the logger so that a sysadmin // can configure logging for this server independently // of other programs. Logger l = Logger.getLogger(DaytimeServer.class.getName()); l.log(Level.WARNING, "IOException in DaytimeServer", e); } catch (Throwable t) { // If anything else goes wrong (out of memory, for example) // then log the problem and exit. Logger l = Logger.getLogger(DaytimeServer.class.getName()); l.log(Level.SEVERE, "FATAL error in DaytimeServer", t); System.exit(1); } } } catch (Exception e) { // This is a startup error: there is no need to log it; // just print a message and exit System.err.println(e); System.exit(1); } }
From source file:vortex.demo.VortexSparkTwitterDemo.java
public static void main(String[] args) { // URL of the Spark cluster final String sparkURL = "local[4]"; // use four threads on the local machine // The directory that will be used for check pointing final String defaultCheckpointDir = System.getProperty("java.io.tmpdir") + File.pathSeparator + "spark"; final String checkPointDir = System.getProperty("vortex.spark.checkpointdir", defaultCheckpointDir); if (!configureTwitterCredentials()) { LOG.info("Unable to configure Twitter credentials exiting."); System.exit(1);// ww w. j a v a2 s. c o m } // Configure Spark and setup the Spark streaming context final SparkConf conf = new SparkConf().setAppName("VortexSparkTwitterDemo").setMaster(sparkURL); final Duration batchDuration = new Duration(1000); final JavaStreamingContext streamingContext = new JavaStreamingContext(conf, batchDuration); streamingContext.checkpoint(checkPointDir); // Create a new stream of // "iot", "Internet of Things", "M2M", "mqtt" final JavaDStream<Status> tweets = TwitterUtils.createStream(streamingContext, FILTER, StorageLevel.MEMORY_ONLY()); final JavaDStream<String> statuses = tweets.map(new Function<Status, String>() { @Override public String call(Status status) throws Exception { return status.getText(); } }); final JavaDStream<String> words = statuses.flatMap(new FlatMapFunction<String, String>() { @Override public Iterable<String> call(String s) throws Exception { return Arrays.asList(s.split(" ")); } }); final JavaDStream<String> hashtags = words.filter(new Function<String, Boolean>() { @Override public Boolean call(String word) throws Exception { return word.startsWith("#"); } }); final JavaPairDStream<String, Integer> tuples = hashtags .mapToPair(new PairFunction<String, String, Integer>() { @Override public Tuple2<String, Integer> call(String s) throws Exception { return new Tuple2<String, Integer>(s, 1); } }); final JavaPairDStream<String, Integer> counts = tuples .reduceByKeyAndWindow(new Function2<Integer, Integer, Integer>() { @Override public Integer call(Integer i1, Integer i2) throws Exception { return i1 + i2; } }, new Function2<Integer, Integer, Integer>() { @Override public Integer call(Integer i1, Integer i2) throws Exception { return i1 - i2; } }, new Duration(60 * 5 * 1000), new Duration(1 * 1000)); final JavaPairDStream<Integer, String> swappedCounts = counts .mapToPair(new PairFunction<Tuple2<String, Integer>, Integer, String>() { @Override public Tuple2<Integer, String> call(Tuple2<String, Integer> in) throws Exception { return in.swap(); } }); final JavaPairDStream<Integer, String> sortedCounts = swappedCounts .transformToPair(new Function<JavaPairRDD<Integer, String>, JavaPairRDD<Integer, String>>() { @Override public JavaPairRDD<Integer, String> call(JavaPairRDD<Integer, String> in) throws Exception { return in.sortByKey(false); } }); sortedCounts.foreach(new Function<JavaPairRDD<Integer, String>, Void>() { @Override public Void call(JavaPairRDD<Integer, String> rdd) throws Exception { int idx = 0; int[] count = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; String[] hashtag = { "", "", "", "", "", "", "", "", "", "" }; StringBuilder sb = new StringBuilder("\nTop 10 hashtags:\n"); for (Tuple2<Integer, String> next : rdd.take(10)) { count[idx] = next._1(); try { final ByteBuffer encoded = encoder.encode(CharBuffer.wrap(next._2())); hashtag[idx] = new String(encoded.array(), "US-ASCII"); } catch (Exception ex) { hashtag[idx] = "Encoding error"; } idx++; sb.append(next.toString()).append("\n"); } final TopTenHashtagsType stats = new TopTenHashtagsType(KEY, count, hashtag); System.out.println(sb.toString()); getWriter().write(stats); return null; } }); streamingContext.start(); }
From source file:Main.java
private static byte[] encode(final Charset charset, final String string) { ByteBuffer encoded = charset.encode(CharBuffer.wrap(string)); return encoded.array(); }
From source file:Main.java
/** * Decode/unescape a portion of a URL, to use with the query part ensure {@code plusAsBlank} is true. * * @param content the portion to decode * @param charset the charset to use * @param plusAsBlank if {@code true}, then convert '+' to space (e.g. for www-url-form-encoded content), otherwise leave as is. * @return encoded string/*from w ww. j a v a 2s . c o m*/ */ private static String urldecode(final String content, final Charset charset, final boolean plusAsBlank) { if (content == null) { return null; } ByteBuffer bb = ByteBuffer.allocate(content.length()); CharBuffer cb = CharBuffer.wrap(content); while (cb.hasRemaining()) { char c = cb.get(); if (c == '%' && cb.remaining() >= 2) { char uc = cb.get(); char lc = cb.get(); int u = Character.digit(uc, 16); int l = Character.digit(lc, 16); if (u != -1 && l != -1) { bb.put((byte) ((u << 4) + l)); } else { bb.put((byte) '%'); bb.put((byte) uc); bb.put((byte) lc); } } else if (plusAsBlank && c == '+') { bb.put((byte) ' '); } else { bb.put((byte) c); } } bb.flip(); return charset.decode(bb).toString(); }