An Explanation Of The Java Queue Interface

There is lots to learn about the Java queue. The taskscheduler is just one small element of this. Let's look first at the types of queues that exist within Java. First, there is the thread safety. This is necessary for those who don't want a queue to be accessible from a range of different threads. If this is the case, a LinkedList is the best option to use as a queue. Other implementations, however, offer high efficient thread safety. Then, there is the blocking or non blocking issue. There are a range of implementations for blocking available.

These implementations give an extra method of putting and removing items from a queue. It is possible to block up to the point that the operation is possible. Furthermore, you can put a time limit on this.Next, a Java developer needs to think about issues around the advanced queue. For instance, is it bound or non bound? It can be very beneficial to place an upper limit on the amount of items that can be placed within the queue. By doing so, a thread pool won't queue up an unmanageable number of jobs whenever a machine in busy. There are a number of other special operations too. For instance, Java can give an implementation to make it possible to sort by priority. Other implementations are in place to place a delay on any item that is in the queue.

So why should you use a Java queue? After all, since it has a number of restrictions on it, it sounds more logical to use something such as LinkedList1 or ArrayList. Sure, they are boring and old, but they work just fine right? There are actually three main reasons as to why you should use this type of queue. First of all, a queue can provide the exact concept of what you actually want. Secondly, a queue prevents random access. This means that it is possible to optimize it for concurrency. Last but not least, Java offers the BlockingQueue. By using this, a number of the implementations are able to take some of the manual work away from the most commonly used queues.You may wonder where we could need a queue or a taskscheduler on a conceptual manner. If there is a producer to consumer pattern, this is where you need to think about it.

A producer to consumer pattern is found when a thread makes or produces a whole list of tasks or jobs. A second thread then picks these up. Yes, it is possible to use a boring and old LinkedList, so long as it is synchronized, but this is only the case if that would be all that we wanted to do with the jobs. If access is restricted to both the beginning and end (head and tail) of a queue, it makes it possible for the queue to optimize for any concurrent access.One of the best places to use an advanced queue is within a thread pool's work queue. Java offers the ThreadPoolExecutor class.

Once a developer constructs this specific class, it is possible for that queue to pass within the thread pool that should be used. It is also possible to design a thread pool that has a utility method that is offered by the Executors class. In this case, a BlockingQueue (set up as default) is the best version to use.