poll():移除并获取队首元素,若成功,则返回队首元素;否则返回null; peek():获取队首元素,若成功,则返回队首元素;否则返回null 对于非阻塞队列,一般情况下建议使用offer、poll和peek三个方法,不建议使用add和remove方法。因为使用offer、poll和peek三个方法可以通过返回值判断操作成功与否,而使用add和remove方法却不能...
poll() :移除并获取队首元素,若成功,则返回队首元素;否则返回null; peek() :获取队首元素,若成功,则返回队首元素;否则返回null。 阻塞队列 非阻塞队列的五种方法阻塞队列都包括,但是加上了同步措施。此外还有 put(E e) : 用来向队尾存入元素,如果队列满,则等待; take() : 用来从队首取元素,如果队列为...
poll():移除并获取队首元素,若成功,则返回队首元素;否则返回null; peek():获取队首元素,若成功,则返回队首元素;否则返回null 对于非阻塞队列,一般情况下建议使用offer、poll和peek三个方法,不建议使用add和remove方法。因为使用offer、poll和peek三个方法可以通过返回值判断操作成功与否,而使用add和remove方法却不能...
toString()); // get head of PriorityBlockingQueue String head = names.peek(); // print head of PriorityBlockingQueue System.out.println("Head of Queue: " + head); // remove one name from head names.poll(); System.out.println("First Name from head is removed"); // print PrioQueue...
PrioQueue: [416165, 464161] Head of Queue: 416165 示例2:为了说明PriorityBlockingQueue的peek()方法,该方法包含名称列表。 // Java Program Demonstratepeek()// method of PriorityBlockingQueueimportjava.util.concurrent.PriorityBlockingQueue;publicclassGFG{publicstaticvoidmain(String[] args){// define capac...
poll(): Removes and brings back the element that is currently at the front of the queue. It returns null if the queue has no items in it. peek(): Without deleting it, returns the element at the front of the queue. It returns null if the queue has no items in it. add(E e): ...
headof this queue is theleastelement with respect to the specified ordering. If multiple elements are tied for least value, the head is one of those elements -- ties are broken arbitrarily. The queue retrieval operationspoll,remove,peek, andelementaccess the element at the head of the queue....
The head of this queue is the least element with respect to the specified ordering. If multiple elements are tied for least value, the head is one of those elements -- ties are broken arbitrarily. The queue retrieval operationspoll,remove,peek, andelementaccess the element at the head of th...
retrieval operations poll, remove, peek, and element access the element at the head of the queue...
remove、poll、take三个方法都是获取元素,但是各自的具体实现又不一样,各自的使用场景也不相同。这三个方法在获取元素的时候都会先获得Lock锁,获取成功后释放锁。这里主要介绍take方法 peek与element方法与上面的方法又不相同,只会读取元素而不会把他们从队列中移除。 public E take() throws InterruptedException { ...