Queue Interface

  • Used to represent a group of individual objects where all objects are present prior to processing.
  • Queue is the child interface of collection.
  • Queue Interface and all its implementation classes came in java 1.5 into collections.

Implementation Classes for Queue :

  • PriorityQueue
  • BlockingQueue
    • LinkedBlockingQueue
    • PriorityBlockingQueue

Features of Queue :

  • When we need to implement logic in first in first out (FIFO) methodology.
  • We can change the logic of queue based on requirement like Blocking, priority etc.

Method

  • offer(Object o)
    • Adding an object to queue
  • poll()
    • Remove and return the head element of queue
  • remove()
    • Remove and return the head element of queue
    • If queue is empty, it gives Null pointer exception
  • peek()
    • Return the head element of queue
  • element()
    • Return the head element of queue
    • If queue is empty, it gives No such element exception

Leave a Comment