[Commons]——队列包装

<pre name="code" class="java">public class test5 {public static void main(String[] args) {//circular();//readOnly();//predicate();}public static void predicate(){//断言队列CircularFifoQueue<String> queue=new CircularFifoQueue<String>(4);queue.add("a");queue.add("b");queue.add("c");Predicate pre=NotNullPredicate.INSTANCE;Queue<String> preQueue=PredicatedQueue.predicatedQueue(queue, pre);//包装成对应的队列preQueue.add(null);}public static void readOnly(){//只读队列CircularFifoQueue<String> queue=new CircularFifoQueue<String>(2);queue.add("a");queue.add("b");queue.add("c");Queue<String> readOnlyQueue=UnmodifiableQueue.unmodifiableQueue(queue);//返回一个queuereadOnlyQueue.add("d");Iterator<String> iterator=readOnlyQueue.iterator();while(iterator.hasNext()){System.out.print(iterator.next()+" ");}}public static void circular(){//循环队列CircularFifoQueue<Integer> circularFifoQueue=new CircularFifoQueue<Integer>(3);circularFifoQueue.add(1);circularFifoQueue.add(2);circularFifoQueue.add(3);circularFifoQueue.add(4);for (int i = 0; i < circularFifoQueue.size(); i++) {System.out.print(circularFifoQueue.get(i)+"  ");}}}