Package overit.geocall.util

Class LinkedBlockingQueue<T>

java.lang.Object
overit.geocall.util.LinkedBlockingQueue<T>
public class LinkedBlockingQueue<T> extends Object
This queue orders elements FIFO (first-in-first-out). The head of the queue is that element that has been on the queue the longest time. The tail of the queue is that element that has been on the queue the shortest time. New elements are inserted at the tail of the queue, and the queue retrieval operations obtain elements at the head of the queue. This queue can contains only a limited number of entry (specified by the setCapacity(int) method); the extra ones must wait the removal of at least one entry.

  • Constructor Summary

    Constructors
    Constructor
    Description
    LinkedBlockingQueue()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Atomically removes all of the elements from this queue.
    boolean
    contains(T o)
    Returns true if this queue contains the specified element.
    boolean
    offer(T e)
    Inserts the specified element at the tail of this queue if it is possible to do so immediately without exceeding the queue's capacity, returning true upon success and false if this queue is full.
    T
    poll()
    Retrieves and removes the head of this queue, or returns null if this queue is empty.
    T
    poll(long timeout)
    Retrieves and removes the head of this queue, waiting if necessary until an element becomes available.
    void
    put(T e)
    Inserts the specified element at the tail of this queue, waiting if necessary for space to become available.
    int
    remainingCapacity()
    Returns the number of additional elements that this queue can ideally (in the absence of memory or resource constraints) accept without blocking.
    void
    setCapacity(int capacity)
    Set the maximum number of entry that the queue can holds.
    int
    size()
    Returns the number of elements in this queue.
    T
    take()
    Retrieves and removes the head of this queue, waiting if necessary until an element becomes available.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • LinkedBlockingQueue

      public LinkedBlockingQueue()

  • Method Details

    • setCapacity

      public void setCapacity(int capacity)
      Set the maximum number of entry that the queue can holds. This value can be dynamically changed at runtime
      Parameters:
      capacity - the maximum number of entry that the queue can holds

    • offer

      public boolean offer(T e)
      Inserts the specified element at the tail of this queue if it is possible to do so immediately without exceeding the queue's capacity, returning true upon success and false if this queue is full.
      Parameters:
      e - the element to add
      Returns:
      true if the element was added to this queue, else false
      Throws:
      NullPointerException - if the specified element is null

    • put

      public void put(T e) throws InterruptedException
      Inserts the specified element at the tail of this queue, waiting if necessary for space to become available.
      Parameters:
      e - the element to add
      Throws:
      InterruptedException - if interrupted while waiting
      NullPointerException - if the specified element is null

    • poll

      public T poll()
      Retrieves and removes the head of this queue, or returns null if this queue is empty.
      Returns:
      he head of this queue, or null if this queue is empty

    • poll

      public T poll(long timeout)
      Retrieves and removes the head of this queue, waiting if necessary until an element becomes available.
      Parameters:
      timeout - the maximum time to wait in milliseconds.
      Returns:
      the head of this queue or null if the timeout has passed and the queue is still empty

    • take

      public T take() throws InterruptedException
      Retrieves and removes the head of this queue, waiting if necessary until an element becomes available.
      Returns:
      the head of this queue
      Throws:
      InterruptedException - if interrupted while waiting

    • clear

      public void clear()
      Atomically removes all of the elements from this queue. The queue will be empty after this call returns.

    • contains

      public boolean contains(T o)
      Returns true if this queue contains the specified element. More formally, returns true if and only if this queue contains at least one element e such that o.equals(e).
      Parameters:
      o - object to be checked for containment in this queue
      Returns:
      true if this queue contains the specified element

    • size

      public int size()
      Returns the number of elements in this queue.
      Returns:
      the number of elements in this queue

    • remainingCapacity

      public int remainingCapacity()
      Returns the number of additional elements that this queue can ideally (in the absence of memory or resource constraints) accept without blocking. This is always equal to the initial capacity of this queue less the current size of this queue. Note that you cannot always tell if an attempt to insert an element will succeed by inspecting remainingCapacity because it may be the case that another thread is about to insert or remove an element.
      Returns:
      the remaining capacity