Improving performance with stacks and queues

Stacks and queues are almost always grouped because they can both be used to manage and manipulate collections of data elements. They are both linear stacks; that’s where their similarities end. While grouped, there are key differences in how they operate. In this section, we’ll look at how to implement stacks and queues and how to optimize them for high-performance Java applications.

Implementing stacks

Stacks are linear data structures that use the last in, first out (LIFO) principle of element management. With stacks, elements are added to and removed from the top of the stack. We push elements to the top, peek to view an element, and pop to remove the top element.

The following example demonstrates how to create a stack in Java. You will notice that we start by importing the java.util.Stack package:

import java.util.Stack;
public class Example8 {
  public static void main(String[] args) {
  ...