List of usage examples for java.nio ByteBuffer flip
public final Buffer flip()
From source file:com.openteach.diamond.network.waverider.network.Packet.java
public static void main(String[] args) { /*System.out.println("[DEBUG] Packet Header size = " + getHeaderSize()); //ww w. jav a2 s . c o m SlaveState slaveState = new SlaveState(); slaveState.setId(1L); slaveState.setIsMasterCandidate(false); Command command = CommandFactory.createHeartbeatCommand(slaveState.toByteBuffer()); Packet packet = Packet.newDataPacket(command); ByteBuffer buffer = packet.marshall(); Packet p = Packet.unmarshall(buffer); Command cmd = Command.unmarshall(p.getPayLoad()); SlaveState ss = SlaveState.fromByteBuffer(cmd.getPayLoad()); System.out.println(cmd.toString()); // Test 2 MasterState masterState = new MasterState(); masterState.setId(1L); masterState.setIp("127.0.0.1"); masterState.setPort(8206); List<SessionState> sessionStateList = new LinkedList<SessionState>(); masterState.setSessionStateList(sessionStateList); SessionState sessionState = null; for(int i = 0; i < 10; i++) { sessionState = new SessionState(); sessionState.setIp("127.0.0.1"); sessionState.setPriority(1L); sessionState.setIsMasterCandidate(false); sessionStateList.add(sessionState); } Command command2 = CommandFactory.createHeartbeatCommand(masterState.toByteBuffer()); Packet packet2 = Packet.newDataPacket(command2); ByteBuffer buffer2 = packet2.marshall(); Packet p2 = Packet.unmarshall(buffer2); Command cmd2 = Command.unmarshall(p2.getPayLoad()); MasterState ms = MasterState.fromByteBuffer(cmd2.getPayLoad()); System.out.println(cmd.toString()); */ System.out.println("[DEBUG] Packet Header size = " + getHeaderSize()); BlockingQueue<ByteBuffer> queue = new LinkedBlockingQueue<ByteBuffer>(); Random rand = new Random(); int count = 0; int size = 0; for (int i = 0; i < 100000; i++) { SlaveState state = new SlaveState(); state.setId(Long.valueOf(i)); state.setIsMasterCandidate(true); Packet packet = Packet.newDataPacket( CommandFactory.createCommand(Command.AVAILABLE_COMMAND_START, state.toByteBuffer())); ByteBuffer buffer = packet.marshall(); rand.setSeed(System.currentTimeMillis()); count = rand.nextInt(100) + 1; size = buffer.remaining() / count; for (int j = 0; j < count; j++) { ByteBuffer buf = null; if (j == count - 1) { buf = ByteBuffer.allocate(buffer.remaining() - j * size); buf.put(buffer.array(), j * size, buffer.remaining() - j * size); } else { buf = ByteBuffer.allocate(size); buf.put(buffer.array(), j * size, size); } buf.flip(); queue.add(buf); } } for (int i = 0; i < 100000; i++) { //Packet packet = Packet.parse(queue); //Command commad = Command.unmarshall(packet.getPayLoad()); //SlaveState state = SlaveState.fromByteBuffer(commad.getPayLoad()); //System.out.println(state.toString()); } }
From source file:Test.java
public static void main(String[] args) throws IOException { Path path = Paths.get("/users.txt"); try (SeekableByteChannel sbc = Files.newByteChannel(path)) { ByteBuffer buffer = ByteBuffer.allocate(1024); sbc.position(4);//ww w.j a v a 2 s . co m sbc.read(buffer); for (int i = 0; i < 5; i++) { System.out.print((char) buffer.get(i)); } buffer.clear(); sbc.position(0); sbc.read(buffer); for (int i = 0; i < 4; i++) { System.out.print((char) buffer.get(i)); } sbc.position(0); buffer = ByteBuffer.allocate(1024); String encoding = System.getProperty("file.encoding"); int numberOfBytesRead = sbc.read(buffer); System.out.println("Number of bytes read: " + numberOfBytesRead); while (numberOfBytesRead > 0) { buffer.rewind(); System.out.print("[" + Charset.forName(encoding).decode(buffer) + "]"); buffer.flip(); numberOfBytesRead = sbc.read(buffer); System.out.println("\nNumber of bytes read: " + numberOfBytesRead); } } }
From source file:org.apache.hadoop.hdfs.hoss.db.FileStreamStore.java
public static void main(String[] args) { final int BUFFER_LEN = 4096;//65536 final int TOTAL = 10000000; FileStreamStore fss = new FileStreamStore("./data/stream", BUFFER_LEN); final ByteBuffer buf = ByteBuffer.allocate(BUFFER_LEN); final long[] offset = new long[TOTAL]; fss.delete();// w w w . j a va 2 s. c om fss.open(); // Parameters fss.setFlushOnWrite(false); fss.setSyncOnFlush(false); fss.setAlignBlocks(true); long start = System.currentTimeMillis(); for (int i = 0; i < TOTAL; i++) { buf.clear(); StringSerializer.fromStringToBuffer(buf, "hehe" + i); buf.flip(); offset[i] = fss.write(buf); } fss.sync(); //System.out.println(ArrayUtils.toString(offset)); System.out.println("write time: " + (System.currentTimeMillis() - start) / 1000); start = System.currentTimeMillis(); long newOffset = 0; for (int i = 0; i < TOTAL; i++) { buf.clear(); newOffset = fss.read(newOffset, buf); if (newOffset < 0) { System.out.println("Error trying read offset " + i + " size=" + fss.size()); break; } StringSerializer.fromBufferToString(buf); //System.out.print(hehe + "\t"); } System.out.println("read time: " + (System.currentTimeMillis() - start) / 1000); }
From source file:Lock.java
public static void main(String args[]) throws IOException, InterruptedException { RandomAccessFile file = null; // The file we'll lock FileChannel f = null; // The channel to the file FileLock lock = null; // The lock object we hold try { // The finally clause closes the channel and releases the lock // We use a temporary file as the lock file. String tmpdir = System.getProperty("java.io.tmpdir"); String filename = Lock.class.getName() + ".lock"; File lockfile = new File(tmpdir, filename); // Create a FileChannel that can read and write that file. // Note that we rely on the java.io package to open the file, // in read/write mode, and then just get a channel from it. // This will create the file if it doesn't exit. We'll arrange // for it to be deleted below, if we succeed in locking it. file = new RandomAccessFile(lockfile, "rw"); f = file.getChannel();//from w w w . j a va2 s. co m // Try to get an exclusive lock on the file. // This method will return a lock or null, but will not block. // See also FileChannel.lock() for a blocking variant. lock = f.tryLock(); if (lock != null) { // We obtained the lock, so arrange to delete the file when // we're done, and then write the approximate time at which // we'll relinquish the lock into the file. lockfile.deleteOnExit(); // Just a temporary file // First, we need a buffer to hold the timestamp ByteBuffer bytes = ByteBuffer.allocate(8); // a long is 8 bytes // Put the time in the buffer and flip to prepare for writing // Note that many Buffer methods can be "chained" like this. bytes.putLong(System.currentTimeMillis() + 10000).flip(); f.write(bytes); // Write the buffer contents to the channel f.force(false); // Force them out to the disk } else { // We didn't get the lock, which means another instance is // running. First, let the user know this. System.out.println("Another instance is already running"); // Next, we attempt to read the file to figure out how much // longer the other instance will be running. Since we don't // have a lock, the read may fail or return inconsistent data. try { ByteBuffer bytes = ByteBuffer.allocate(8); f.read(bytes); // Read 8 bytes from the file bytes.flip(); // Flip buffer before extracting bytes long exittime = bytes.getLong(); // Read bytes as a long // Figure out how long that time is from now and round // it to the nearest second. long secs = (exittime - System.currentTimeMillis() + 500) / 1000; // And tell the user about it. System.out.println("Try again in about " + secs + " seconds"); } catch (IOException e) { // This probably means that locking is enforced by the OS // and we were prevented from reading the file. } // This is an abnormal exit, so set an exit code. System.exit(1); } // Simulate a real application by sleeping for 10 seconds. System.out.println("Starting..."); Thread.sleep(10000); System.out.println("Exiting."); } finally { // Always release the lock and close the file // Closing the RandomAccessFile also closes its FileChannel. if (lock != null && lock.isValid()) lock.release(); if (file != null) file.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 w w. j a v a 2 s .com 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;/* w ww .j a va2s. 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:edu.hawaii.soest.kilonalu.dvp2.DavisWxParser.java
public static void main(String[] args) { // Ensure we have a path to the binary file if (args.length != 1) { logger.info("Please provide the path to a file containing a binary LOOP packet."); System.exit(1);/*from w w w . j av a2 s . co m*/ } else { try { // open and read the file File packetFile = new File(args[0]); FileInputStream fis = new FileInputStream(packetFile); FileChannel fileChannel = fis.getChannel(); ByteBuffer inBuffer = ByteBuffer.allocateDirect(8192); ByteBuffer packetBuffer = ByteBuffer.allocateDirect(8192); while (fileChannel.read(inBuffer) != -1 || inBuffer.position() > 0) { inBuffer.flip(); packetBuffer.put(inBuffer.get()); inBuffer.compact(); } fileChannel.close(); fis.close(); packetBuffer.put(inBuffer.get()); // create an instance of the parser, and report the field contents after parsing DavisWxParser davisWxParser = new DavisWxParser(packetBuffer); // Set up a simple logger that logs to the console PropertyConfigurator.configure(davisWxParser.getLogConfigurationFile()); logger.info("loopID: " + davisWxParser.getLoopID()); logger.info("barTrend: " + davisWxParser.getBarTrend()); logger.info("barTrendAsString: " + davisWxParser.getBarTrendAsString()); logger.info("packetType: " + davisWxParser.getPacketType()); logger.info("nextRecord: " + davisWxParser.getNextRecord()); logger.info("barometer: " + davisWxParser.getBarometer()); logger.info("insideTemperature: " + davisWxParser.getInsideTemperature()); logger.info("insideHumidity: " + davisWxParser.getInsideHumidity()); logger.info("outsideTemperature: " + davisWxParser.getOutsideTemperature()); logger.info("windSpeed: " + davisWxParser.getWindSpeed()); logger.info("tenMinuteAverageWindSpeed: " + davisWxParser.getTenMinuteAverageWindSpeed()); logger.info("windDirection: " + davisWxParser.getWindDirection()); logger.info( "extraTemperatures: " + Arrays.toString(davisWxParser.getExtraTemperatures())); logger.info( "soilTemperatures: " + Arrays.toString(davisWxParser.getSoilTemperatures())); logger.info( "leafTemperatures: " + Arrays.toString(davisWxParser.getLeafTemperatures())); logger.info("outsideHumidity: " + davisWxParser.getOutsideHumidity()); logger.info( "extraHumidities: " + Arrays.toString(davisWxParser.getExtraHumidities())); logger.info("rainRate: " + davisWxParser.getRainRate()); logger.info("uvRadiation: " + davisWxParser.getUvRadiation()); logger.info("solarRadiation: " + davisWxParser.getSolarRadiation()); logger.info("stormRain: " + davisWxParser.getStormRain()); logger.info("currentStormStartDate: " + davisWxParser.getCurrentStormStartDate()); logger.info("dailyRain: " + davisWxParser.getDailyRain()); logger.info("monthlyRain: " + davisWxParser.getMonthlyRain()); logger.info("yearlyRain: " + davisWxParser.getYearlyRain()); logger.info("dailyEvapoTranspiration: " + davisWxParser.getDailyEvapoTranspiration()); logger.info("monthlyEvapoTranspiration: " + davisWxParser.getMonthlyEvapoTranspiration()); logger.info("yearlyEvapoTranspiration: " + davisWxParser.getYearlyEvapoTranspiration()); logger.info("soilMoistures: " + Arrays.toString(davisWxParser.getSoilMoistures())); logger.info("leafWetnesses: " + Arrays.toString(davisWxParser.getLeafWetnesses())); logger.info("insideAlarm: " + davisWxParser.getInsideAlarm()); logger.info("rainAlarm: " + davisWxParser.getRainAlarm()); logger.info("outsideAlarms: " + davisWxParser.getOutsideAlarms()); logger.info("extraTemperatureHumidityAlarms: " + davisWxParser.getExtraTemperatureHumidityAlarms()); logger.info("soilLeafAlarms: " + davisWxParser.getSoilLeafAlarms()); logger.info("transmitterBatteryStatus: " + davisWxParser.getTransmitterBatteryStatus()); logger.info("consoleBatteryVoltage: " + davisWxParser.getConsoleBatteryVoltage()); logger.info("forecastIconValues: " + davisWxParser.getForecastAsString()); logger.info("forecastRuleNumber: " + davisWxParser.getForecastRuleNumberAsString()); logger.info("timeOfSunrise: " + davisWxParser.getTimeOfSunrise()); logger.info("timeOfSunset: " + davisWxParser.getTimeOfSunset()); logger.info("recordDelimiter: " + davisWxParser.getRecordDelimiterAsHexString()); logger.info("crcChecksum: " + davisWxParser.getCrcChecksum()); } catch (java.io.FileNotFoundException fnfe) { fnfe.printStackTrace(); } catch (java.io.IOException ioe) { ioe.printStackTrace(); } } }
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 ava2s . c o m // 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:Main.java
public static String convert(final ByteBuffer src) { src.flip(); final StringBuilder buffer = new StringBuilder(src.remaining()); while (src.hasRemaining()) { buffer.append((char) (src.get() & 0xff)); }//w ww. j av a2 s . com return buffer.toString(); }
From source file:Main.java
private static byte[] getByteArrayFromBuffer(ByteBuffer byteBuf) { byteBuf.flip(); byte[] row = new byte[byteBuf.limit()]; byteBuf.get(row);//from w w w . java2s. c o m byteBuf.clear(); return row; }