producer consumer

Mark......

public class ProducerConsumer {private LinkedBlockingQueue<DBObject> _queue = new LinkedBlockingQueue<DBObject>(1000);private final Lock _lock = new ReentrantLock();private DBCollection _coll = null;private volatile DBCursor _cur = null;private int _producers;private int _customers;private volatile boolean _producerRunning = false;private volatile boolean _finishedConsume = false;private AtomicInteger _finishedProducers = new AtomicInteger(0);private AnswerScorers scorers = new AnswerScorers("", -5000, 10000);public ProducerConsumer(DBCollection coll, int producers, int customers) {this._coll = coll;this._producers = producers;this._customers = customers;}/** * 另外一种串行获取数据的方式。 * @return */private synchronized DBObject next() {if (!_cur.hasNext()) {return null;}return _cur.next();}public void start() {this._cur = _coll.find();_producerRunning = true;_finishedProducers.set(0);for (int i = 0; i < _producers; i++) {new Producer().start();}for (int i = 0; i < _customers; i++) {new Consumer().start();}try {while (!_finishedConsume) {Thread.sleep(1000);}} catch (InterruptedException e) {e.printStackTrace();}}/** * 生产一条数据，放在数据队列。 * @author xiuleili * */class Producer extends Thread {public void run() {int count = 0;try {while (true) {// DBObject dbo = next();// this code has the same effect with next lines:DBObject dbo = null;_lock.lock();if (_cur.hasNext()) {dbo = _cur.next();}_lock.unlock();if(dbo == null){break;}count++;AnswerNLP answer = buildAnswerNlpFromDBO(dbo);int score = scorers.score(answer);dbo.put("score", new Integer(score));_queue.put(dbo);}} catch (Exception e) {} finally {System.out.println(Thread.currentThread().getName() + " total produced " + count);if (_finishedProducers.addAndGet(1) == _producers) {_producerRunning = false;}}}}/** * 消费一条数据，写入数据库。 * @author xiuleili * */class Consumer extends Thread {public void run() {int count = 0;while (_producerRunning || !_queue.isEmpty()) {try {// 取出一个对象DBObject dbo = _queue.poll(300, TimeUnit.MILLISECONDS);if (dbo == null) {continue;}DBObject query = new BasicDBObject("answerId", dbo.get("answerId"));DBObject update = new BasicDBObject("$set", new BasicDBObject("score", dbo.get("score")));_coll.update(query, update);count++;} catch (InterruptedException e) {System.out.println("producer is interrupted!");}}System.out.println(Thread.currentThread().getName() + " total consumed " + count);_finishedConsume = true;}}}/** * 使用多线程的方法进行操作。多个生产者进行分析，多个个消费者进行数据库写。 */public static void scoreAnswersThreads() {DBCollection coll = MongoDriver.getCollection("mongodb://10.13.95.60/test.answerNLP");new DBDataManage().new ProducerConsumer(coll, 10, 2).start();}