List of usage examples for java.util LinkedList getFirst
public E getFirst()
From source file:Main.java
public static void main(String[] args) { LinkedList<String> lList = new LinkedList<String>(); lList.add("1"); lList.add("2"); lList.add("3"); lList.add("4"); lList.add("5"); System.out.println("First element of LinkedList is : " + lList.getFirst()); System.out.println("Last element of LinkedList is : " + lList.getLast()); }
From source file:MainClass.java
public static void main(String[] a) { LinkedList list = new LinkedList(); list.add("A"); list.add("B"); list.add("C"); list.add("D"); list.addFirst("X"); list.addLast("Z"); System.out.println(list);//from w w w .jav a 2 s . c o m System.out.println(list.getFirst()); System.out.println(list.getLast()); }
From source file:MainClass.java
public static void main(String[] a) { LinkedList list = new LinkedList(); list.add("A"); list.add("B"); list.add("C"); list.add("D"); list.addFirst("X"); list.addLast("Z"); System.out.println(list);//from w ww .jav a 2 s . c om System.out.println(list.getFirst()); System.out.println(list.getLast()); list.removeFirst(); list.removeLast(); System.out.println(list); }
From source file:Main.java
public static void main(String[] args) { // create a LinkedList LinkedList<String> list = new LinkedList<String>(); // add some elements list.add("Hello"); list.add("from java2s.com"); list.add("10"); // print the list System.out.println("LinkedList:" + list); // print the first element of the list System.out.println("First Element :" + list.getFirst()); }
From source file:com.alibaba.rocketmq.example.benchmark.Consumer.java
public static void main(String[] args) throws MQClientException { Options options = ServerUtil.buildCommandlineOptions(new Options()); CommandLine commandLine = ServerUtil.parseCmdLine("benchmarkConsumer", args, buildCommandlineOptions(options), new PosixParser()); if (null == commandLine) { System.exit(-1);//from w w w . j a v a 2 s . c om } final String topic = commandLine.hasOption('t') ? commandLine.getOptionValue('t').trim() : "BenchmarkTest"; final String groupPrefix = commandLine.hasOption('g') ? commandLine.getOptionValue('g').trim() : "benchmark_consumer"; final String isPrefixEnable = commandLine.hasOption('p') ? commandLine.getOptionValue('p').trim() : "true"; String group = groupPrefix; if (Boolean.parseBoolean(isPrefixEnable)) { group = groupPrefix + "_" + Long.toString(System.currentTimeMillis() % 100); } System.out.printf("topic %s group %s prefix %s%n", topic, group, isPrefixEnable); final StatsBenchmarkConsumer statsBenchmarkConsumer = new StatsBenchmarkConsumer(); final Timer timer = new Timer("BenchmarkTimerThread", true); final LinkedList<Long[]> snapshotList = new LinkedList<Long[]>(); timer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { snapshotList.addLast(statsBenchmarkConsumer.createSnapshot()); if (snapshotList.size() > 10) { snapshotList.removeFirst(); } } }, 1000, 1000); timer.scheduleAtFixedRate(new TimerTask() { private void printStats() { if (snapshotList.size() >= 10) { Long[] begin = snapshotList.getFirst(); Long[] end = snapshotList.getLast(); final long consumeTps = (long) (((end[1] - begin[1]) / (double) (end[0] - begin[0])) * 1000L); final double averageB2CRT = (end[2] - begin[2]) / (double) (end[1] - begin[1]); final double averageS2CRT = (end[3] - begin[3]) / (double) (end[1] - begin[1]); System.out.printf( "Consume TPS: %d Average(B2C) RT: %7.3f Average(S2C) RT: %7.3f MAX(B2C) RT: %d MAX(S2C) RT: %d%n", consumeTps, averageB2CRT, averageS2CRT, end[4], end[5]); } } @Override public void run() { try { this.printStats(); } catch (Exception e) { e.printStackTrace(); } } }, 10000, 10000); DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(group); consumer.setInstanceName(Long.toString(System.currentTimeMillis())); consumer.subscribe(topic, "*"); consumer.registerMessageListener(new MessageListenerConcurrently() { @Override public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) { MessageExt msg = msgs.get(0); long now = System.currentTimeMillis(); statsBenchmarkConsumer.getReceiveMessageTotalCount().incrementAndGet(); long born2ConsumerRT = now - msg.getBornTimestamp(); statsBenchmarkConsumer.getBorn2ConsumerTotalRT().addAndGet(born2ConsumerRT); long store2ConsumerRT = now - msg.getStoreTimestamp(); statsBenchmarkConsumer.getStore2ConsumerTotalRT().addAndGet(store2ConsumerRT); compareAndSetMax(statsBenchmarkConsumer.getBorn2ConsumerMaxRT(), born2ConsumerRT); compareAndSetMax(statsBenchmarkConsumer.getStore2ConsumerMaxRT(), store2ConsumerRT); return ConsumeConcurrentlyStatus.CONSUME_SUCCESS; } }); consumer.start(); System.out.printf("Consumer Started.%n"); }
From source file:org.apache.rocketmq.example.benchmark.Consumer.java
public static void main(String[] args) throws MQClientException, IOException { Options options = ServerUtil.buildCommandlineOptions(new Options()); CommandLine commandLine = ServerUtil.parseCmdLine("benchmarkConsumer", args, buildCommandlineOptions(options), new PosixParser()); if (null == commandLine) { System.exit(-1);//from www.j a v a 2 s. c o m } final String topic = commandLine.hasOption('t') ? commandLine.getOptionValue('t').trim() : "BenchmarkTest"; final String groupPrefix = commandLine.hasOption('g') ? commandLine.getOptionValue('g').trim() : "benchmark_consumer"; final String isPrefixEnable = commandLine.hasOption('p') ? commandLine.getOptionValue('p').trim() : "true"; final String filterType = commandLine.hasOption('f') ? commandLine.getOptionValue('f').trim() : null; final String expression = commandLine.hasOption('e') ? commandLine.getOptionValue('e').trim() : null; String group = groupPrefix; if (Boolean.parseBoolean(isPrefixEnable)) { group = groupPrefix + "_" + Long.toString(System.currentTimeMillis() % 100); } System.out.printf("topic: %s, group: %s, prefix: %s, filterType: %s, expression: %s%n", topic, group, isPrefixEnable, filterType, expression); final StatsBenchmarkConsumer statsBenchmarkConsumer = new StatsBenchmarkConsumer(); final Timer timer = new Timer("BenchmarkTimerThread", true); final LinkedList<Long[]> snapshotList = new LinkedList<Long[]>(); timer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { snapshotList.addLast(statsBenchmarkConsumer.createSnapshot()); if (snapshotList.size() > 10) { snapshotList.removeFirst(); } } }, 1000, 1000); timer.scheduleAtFixedRate(new TimerTask() { private void printStats() { if (snapshotList.size() >= 10) { Long[] begin = snapshotList.getFirst(); Long[] end = snapshotList.getLast(); final long consumeTps = (long) (((end[1] - begin[1]) / (double) (end[0] - begin[0])) * 1000L); final double averageB2CRT = (end[2] - begin[2]) / (double) (end[1] - begin[1]); final double averageS2CRT = (end[3] - begin[3]) / (double) (end[1] - begin[1]); System.out.printf( "Consume TPS: %d Average(B2C) RT: %7.3f Average(S2C) RT: %7.3f MAX(B2C) RT: %d MAX(S2C) RT: %d%n", consumeTps, averageB2CRT, averageS2CRT, end[4], end[5]); } } @Override public void run() { try { this.printStats(); } catch (Exception e) { e.printStackTrace(); } } }, 10000, 10000); DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(group); consumer.setInstanceName(Long.toString(System.currentTimeMillis())); if (filterType == null || expression == null) { consumer.subscribe(topic, "*"); } else { if (ExpressionType.TAG.equals(filterType)) { String expr = MixAll.file2String(expression); System.out.printf("Expression: %s%n", expr); consumer.subscribe(topic, MessageSelector.byTag(expr)); } else if (ExpressionType.SQL92.equals(filterType)) { String expr = MixAll.file2String(expression); System.out.printf("Expression: %s%n", expr); consumer.subscribe(topic, MessageSelector.bySql(expr)); } else { throw new IllegalArgumentException("Not support filter type! " + filterType); } } consumer.registerMessageListener(new MessageListenerConcurrently() { @Override public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) { MessageExt msg = msgs.get(0); long now = System.currentTimeMillis(); statsBenchmarkConsumer.getReceiveMessageTotalCount().incrementAndGet(); long born2ConsumerRT = now - msg.getBornTimestamp(); statsBenchmarkConsumer.getBorn2ConsumerTotalRT().addAndGet(born2ConsumerRT); long store2ConsumerRT = now - msg.getStoreTimestamp(); statsBenchmarkConsumer.getStore2ConsumerTotalRT().addAndGet(store2ConsumerRT); compareAndSetMax(statsBenchmarkConsumer.getBorn2ConsumerMaxRT(), born2ConsumerRT); compareAndSetMax(statsBenchmarkConsumer.getStore2ConsumerMaxRT(), store2ConsumerRT); return ConsumeConcurrentlyStatus.CONSUME_SUCCESS; } }); consumer.start(); System.out.printf("Consumer Started.%n"); }
From source file:com.damon.rocketmq.example.benchmark.Producer.java
public static void main(String[] args) throws MQClientException, UnsupportedEncodingException { Options options = ServerUtil.buildCommandlineOptions(new Options()); CommandLine commandLine = ServerUtil.parseCmdLine("benchmarkProducer", args, buildCommandlineOptions(options), new PosixParser()); if (null == commandLine) { System.exit(-1);//from w ww. j av a 2s.co m } final String topic = commandLine.hasOption('t') ? commandLine.getOptionValue('t').trim() : "BenchmarkTest"; final int threadCount = commandLine.hasOption('w') ? Integer.parseInt(commandLine.getOptionValue('w')) : 64; final int messageSize = commandLine.hasOption('s') ? Integer.parseInt(commandLine.getOptionValue('s')) : 128; final boolean keyEnable = commandLine.hasOption('k') && Boolean.parseBoolean(commandLine.getOptionValue('k')); System.out.printf("topic %s threadCount %d messageSize %d keyEnable %s%n", topic, threadCount, messageSize, keyEnable); final Logger log = ClientLogger.getLog(); final Message msg = buildMessage(messageSize, topic); final ExecutorService sendThreadPool = Executors.newFixedThreadPool(threadCount); final StatsBenchmarkProducer statsBenchmark = new StatsBenchmarkProducer(); final Timer timer = new Timer("BenchmarkTimerThread", true); final LinkedList<Long[]> snapshotList = new LinkedList<Long[]>(); timer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { snapshotList.addLast(statsBenchmark.createSnapshot()); if (snapshotList.size() > 10) { snapshotList.removeFirst(); } } }, 1000, 1000); timer.scheduleAtFixedRate(new TimerTask() { private void printStats() { if (snapshotList.size() >= 10) { Long[] begin = snapshotList.getFirst(); Long[] end = snapshotList.getLast(); final long sendTps = (long) (((end[3] - begin[3]) / (double) (end[0] - begin[0])) * 1000L); final double averageRT = (end[5] - begin[5]) / (double) (end[3] - begin[3]); System.out.printf( "Send TPS: %d Max RT: %d Average RT: %7.3f Send Failed: %d Response Failed: %d%n", sendTps, statsBenchmark.getSendMessageMaxRT().get(), averageRT, end[2], end[4]); } } @Override public void run() { try { this.printStats(); } catch (Exception e) { e.printStackTrace(); } } }, 10000, 10000); final DefaultMQProducer producer = new DefaultMQProducer("benchmark_producer"); producer.setInstanceName(Long.toString(System.currentTimeMillis())); if (commandLine.hasOption('n')) { String ns = commandLine.getOptionValue('n'); producer.setNamesrvAddr(ns); } producer.setCompressMsgBodyOverHowmuch(Integer.MAX_VALUE); producer.start(); for (int i = 0; i < threadCount; i++) { sendThreadPool.execute(new Runnable() { @Override public void run() { while (true) { try { final long beginTimestamp = System.currentTimeMillis(); if (keyEnable) { msg.setKeys(String.valueOf(beginTimestamp / 1000)); } producer.send(msg); statsBenchmark.getSendRequestSuccessCount().incrementAndGet(); statsBenchmark.getReceiveResponseSuccessCount().incrementAndGet(); final long currentRT = System.currentTimeMillis() - beginTimestamp; statsBenchmark.getSendMessageSuccessTimeTotal().addAndGet(currentRT); long prevMaxRT = statsBenchmark.getSendMessageMaxRT().get(); while (currentRT > prevMaxRT) { boolean updated = statsBenchmark.getSendMessageMaxRT().compareAndSet(prevMaxRT, currentRT); if (updated) break; prevMaxRT = statsBenchmark.getSendMessageMaxRT().get(); } } catch (RemotingException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); try { Thread.sleep(3000); } catch (InterruptedException ignored) { } } catch (InterruptedException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); try { Thread.sleep(3000); } catch (InterruptedException e1) { } } catch (MQClientException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); } catch (MQBrokerException e) { statsBenchmark.getReceiveResponseFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); try { Thread.sleep(3000); } catch (InterruptedException ignored) { } } } } }); } }
From source file:com.alibaba.rocketmq.example.benchmark.Producer.java
public static void main(String[] args) throws MQClientException, UnsupportedEncodingException { Options options = ServerUtil.buildCommandlineOptions(new Options()); CommandLine commandLine = ServerUtil.parseCmdLine("producer", args, buildCommandlineOptions(options), new PosixParser()); if (null == commandLine) { System.exit(-1);/*from w ww.ja v a 2 s .c om*/ } final int threadCount = commandLine.hasOption('t') ? Integer.parseInt(commandLine.getOptionValue('t')) : 64; final int messageSize = commandLine.hasOption('s') ? Integer.parseInt(commandLine.getOptionValue('s')) : 128; final boolean keyEnable = commandLine.hasOption('k') ? Boolean.parseBoolean(commandLine.getOptionValue('k')) : false; System.out.printf("threadCount %d messageSize %d keyEnable %s%n", threadCount, messageSize, keyEnable); final Logger log = ClientLogger.getLog(); final Message msg = buildMessage(messageSize); final ExecutorService sendThreadPool = Executors.newFixedThreadPool(threadCount); final StatsBenchmarkProducer statsBenchmark = new StatsBenchmarkProducer(); final Timer timer = new Timer("BenchmarkTimerThread", true); final LinkedList<Long[]> snapshotList = new LinkedList<Long[]>(); timer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { snapshotList.addLast(statsBenchmark.createSnapshot()); if (snapshotList.size() > 10) { snapshotList.removeFirst(); } } }, 1000, 1000); timer.scheduleAtFixedRate(new TimerTask() { private void printStats() { if (snapshotList.size() >= 10) { Long[] begin = snapshotList.getFirst(); Long[] end = snapshotList.getLast(); final long sendTps = (long) (((end[3] - begin[3]) / (double) (end[0] - begin[0])) * 1000L); final double averageRT = ((end[5] - begin[5]) / (double) (end[3] - begin[3])); System.out.printf( "Send TPS: %d Max RT: %d Average RT: %7.3f Send Failed: %d Response Failed: %d%n"// , sendTps// , statsBenchmark.getSendMessageMaxRT().get()// , averageRT// , end[2]// , end[4]// ); } } @Override public void run() { try { this.printStats(); } catch (Exception e) { e.printStackTrace(); } } }, 10000, 10000); final DefaultMQProducer producer = new DefaultMQProducer("benchmark_producer"); producer.setInstanceName(Long.toString(System.currentTimeMillis())); if (commandLine.hasOption('n')) { String ns = commandLine.getOptionValue('n'); producer.setNamesrvAddr(ns); } producer.setCompressMsgBodyOverHowmuch(Integer.MAX_VALUE); producer.start(); for (int i = 0; i < threadCount; i++) { sendThreadPool.execute(new Runnable() { @Override public void run() { while (true) { try { final long beginTimestamp = System.currentTimeMillis(); if (keyEnable) { msg.setKeys(String.valueOf(beginTimestamp / 1000)); } producer.send(msg); statsBenchmark.getSendRequestSuccessCount().incrementAndGet(); statsBenchmark.getReceiveResponseSuccessCount().incrementAndGet(); final long currentRT = System.currentTimeMillis() - beginTimestamp; statsBenchmark.getSendMessageSuccessTimeTotal().addAndGet(currentRT); long prevMaxRT = statsBenchmark.getSendMessageMaxRT().get(); while (currentRT > prevMaxRT) { boolean updated = statsBenchmark.getSendMessageMaxRT().compareAndSet(prevMaxRT, currentRT); if (updated) break; prevMaxRT = statsBenchmark.getSendMessageMaxRT().get(); } } catch (RemotingException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); try { Thread.sleep(3000); } catch (InterruptedException e1) { } } catch (InterruptedException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); try { Thread.sleep(3000); } catch (InterruptedException e1) { } } catch (MQClientException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); } catch (MQBrokerException e) { statsBenchmark.getReceiveResponseFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); try { Thread.sleep(3000); } catch (InterruptedException e1) { } } } } }); } }
From source file:org.apache.rocketmq.example.benchmark.Producer.java
public static void main(String[] args) throws MQClientException, UnsupportedEncodingException { Options options = ServerUtil.buildCommandlineOptions(new Options()); CommandLine commandLine = ServerUtil.parseCmdLine("benchmarkProducer", args, buildCommandlineOptions(options), new PosixParser()); if (null == commandLine) { System.exit(-1);/*from ww w.j ava 2 s .c o m*/ } final String topic = commandLine.hasOption('t') ? commandLine.getOptionValue('t').trim() : "BenchmarkTest"; final int threadCount = commandLine.hasOption('w') ? Integer.parseInt(commandLine.getOptionValue('w')) : 64; final int messageSize = commandLine.hasOption('s') ? Integer.parseInt(commandLine.getOptionValue('s')) : 128; final boolean keyEnable = commandLine.hasOption('k') && Boolean.parseBoolean(commandLine.getOptionValue('k')); final int propertySize = commandLine.hasOption('p') ? Integer.parseInt(commandLine.getOptionValue('p')) : 0; System.out.printf("topic %s threadCount %d messageSize %d keyEnable %s%n", topic, threadCount, messageSize, keyEnable); final InternalLogger log = ClientLogger.getLog(); final ExecutorService sendThreadPool = Executors.newFixedThreadPool(threadCount); final StatsBenchmarkProducer statsBenchmark = new StatsBenchmarkProducer(); final Timer timer = new Timer("BenchmarkTimerThread", true); final LinkedList<Long[]> snapshotList = new LinkedList<Long[]>(); timer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { snapshotList.addLast(statsBenchmark.createSnapshot()); if (snapshotList.size() > 10) { snapshotList.removeFirst(); } } }, 1000, 1000); timer.scheduleAtFixedRate(new TimerTask() { private void printStats() { if (snapshotList.size() >= 10) { Long[] begin = snapshotList.getFirst(); Long[] end = snapshotList.getLast(); final long sendTps = (long) (((end[3] - begin[3]) / (double) (end[0] - begin[0])) * 1000L); final double averageRT = (end[5] - begin[5]) / (double) (end[3] - begin[3]); System.out.printf( "Send TPS: %d Max RT: %d Average RT: %7.3f Send Failed: %d Response Failed: %d%n", sendTps, statsBenchmark.getSendMessageMaxRT().get(), averageRT, end[2], end[4]); } } @Override public void run() { try { this.printStats(); } catch (Exception e) { e.printStackTrace(); } } }, 10000, 10000); final DefaultMQProducer producer = new DefaultMQProducer("benchmark_producer"); producer.setInstanceName(Long.toString(System.currentTimeMillis())); if (commandLine.hasOption('n')) { String ns = commandLine.getOptionValue('n'); producer.setNamesrvAddr(ns); } producer.setCompressMsgBodyOverHowmuch(Integer.MAX_VALUE); producer.start(); for (int i = 0; i < threadCount; i++) { sendThreadPool.execute(new Runnable() { @Override public void run() { while (true) { try { final Message msg; try { msg = buildMessage(messageSize, topic); } catch (UnsupportedEncodingException e) { e.printStackTrace(); return; } final long beginTimestamp = System.currentTimeMillis(); if (keyEnable) { msg.setKeys(String.valueOf(beginTimestamp / 1000)); } if (propertySize > 0) { if (msg.getProperties() != null) { msg.getProperties().clear(); } int i = 0; int startValue = (new Random(System.currentTimeMillis())).nextInt(100); int size = 0; while (true) { String prop1 = "prop" + i, prop1V = "hello" + startValue; String prop2 = "prop" + (i + 1), prop2V = String.valueOf(startValue); msg.putUserProperty(prop1, prop1V); msg.putUserProperty(prop2, prop2V); size += prop1.length() + prop2.length() + prop1V.length() + prop2V.length(); if (size > propertySize) { break; } i += 2; startValue += 2; } } producer.send(msg); statsBenchmark.getSendRequestSuccessCount().incrementAndGet(); statsBenchmark.getReceiveResponseSuccessCount().incrementAndGet(); final long currentRT = System.currentTimeMillis() - beginTimestamp; statsBenchmark.getSendMessageSuccessTimeTotal().addAndGet(currentRT); long prevMaxRT = statsBenchmark.getSendMessageMaxRT().get(); while (currentRT > prevMaxRT) { boolean updated = statsBenchmark.getSendMessageMaxRT().compareAndSet(prevMaxRT, currentRT); if (updated) break; prevMaxRT = statsBenchmark.getSendMessageMaxRT().get(); } } catch (RemotingException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); try { Thread.sleep(3000); } catch (InterruptedException ignored) { } } catch (InterruptedException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); try { Thread.sleep(3000); } catch (InterruptedException e1) { } } catch (MQClientException e) { statsBenchmark.getSendRequestFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); } catch (MQBrokerException e) { statsBenchmark.getReceiveResponseFailedCount().incrementAndGet(); log.error("[BENCHMARK_PRODUCER] Send Exception", e); try { Thread.sleep(3000); } catch (InterruptedException ignored) { } } } } }); } }
From source file:fi.smaa.libror.MaximalVectorComputation.java
private static RealMatrix listOfRowsToMatrix(LinkedList<RealVector> results) { RealMatrix res = new Array2DRowRealMatrix(results.size(), results.getFirst().getDimension()); for (int i = 0; i < results.size(); i++) { res.setRowVector(i, results.get(i)); }//from w w w. j a v a 2s. co m return res; }