Java Articles - Page 8 of 440

The LinkedHashMap Class is similar to HashMap. But it has an additional feature in comparison to HashMap. The LinkedList class belongs to the java.util package. A doubly linked list is how LinkedList stores its elements. Given that our operations typically include insertion and deletion, LinkedList is the best option. The java.util package contains the LinkedList collection framework. It acts as an implementation of the non-contiguous LinkedList data structure, which saves elements in memory. Methods Used There are five main methods that you can use for iterating HashMap − Using the for loop Making use of a while loop Using ... Read More

The Vector class has been a part of the Java collection system since Java version 1.2. Vectors are sometimes known as Dynamic Arrays because, unlike ordinary arrays, they can expand and contract in size. Ensuring thread-safety, Vectors are synchronized. While there exists a third approach that involves using Apache Commons to iterate through the vector in reverse, this method necessitates the downloading of additional jar files and packages, which is not widely supported by most systems. Essentially, there are only two primary methods to traverse through vector elements in reverse order. Methods Used There are two methods used here − ... Read More

TreeMap is based on the Red-Black tree structure, which is a It is a part of the Java Collections Framework. It is a sorted map and maintains the order of its keys. Its order depends on the natural ordering of the keys or by a Comparator.Since the TreeMap is not a Collection, we cannot use the for-each loop to iterate through it. Instead, we can use the entrySet() method to get a set view of the mappings contained in the map, which we can then iterate over to access the keys and values. Let's explore some scenarios to understand the ... Read More

A data structure known as a 2D list or list of lists can be utilised for saving a collection of data in a two-dimensional format. A row in the 2D list is represented by each inner list in this list of lists. A 2D list could be utilised, for instance, to store the data for a chessboard, where every component in the list corresponds to a single square on the board. Methods Used A 2D list can be iterated in one of the two methods that follow − Using Loops Using iterator Method 1: Employing Loops There are ... Read More

The LinkedHashMap serves the purpose of maintaining the precise order of element addition. It elucidates the method for accessing elements in the sequence they were inserted. In addition to storing values based on their keys, the LinkedHashMap class expands upon the functionalities of the Hash Map class and implements the Map interface. It exclusively accommodates unique elements or mappings. It affords us the flexibility to utilize various data types, such as text, float, integer, etc., for assigning keys and values. By initially reversing the elements, we can alter the order of elements in the linked hash map. Subsequently, we can ... Read More

Spring is a highly popular framework within the Java EE ecosystem. It is an open-source and lightweight framework that empowers Java developers to build reliable, scalable, and simplified business applications. The primary goal of this framework is to offer you a variety of tools for managing your business items. In contrast to conventional Java frameworks and APIs such as JSP, JDBC and Java Servlet, developing web applications is far simpler. In Spring, objects—primarily those controlled by the Spring IoC Container. It plays a significant role in the application. A Bean is nothing more than an object that a Spring Ioc ... Read More

In Java, a class is a fundamental component of object-oriented programming. It serves as a blueprint or template for defining the structure and behavior of objects. A class contains both data, represented by fields or variables, and behaviors, represented by methods or functions, which manipulate that data. In Java, a custom class is a user-defined class that allows you to create objects with specific properties and behaviors tailored to your application's requirements. It serves as a blueprint or template for creating objects of that class type. Custom classes encapsulate related data and operations into a single entity, promoting code organization, ... Read More

The Spring Boot framework incorporates all of Spring's capabilities and features because it is built upon the basis of Spring. Developers are drawn to it because of its effective production-ready environment, which frees them up to focus on the logic of the application rather than on setup and configuration. Microservices-based applications that are suitable for deployment in a production environment may be created quickly thanks to Spring Boot. Some of the key features of Spring Boot are − Auto-configuration − Spring Boot's standout feature is its auto-configuration capability. It analyzes the project's classpath and automatically configures the necessary beans ... Read More

Program in Text and XML Format? In Java, a project's properties file is made up of text-based key-value pairs that are commonly stored with the .properties extension. The key-value pair of contents are presented line by line, and they are often created using notepad, Wordpad, etc. Properties files serve as valuable repositories for storing critical and confidential data. In this article, we will explore the process of creating a properties file using a Java program. The Properties class in this (java.util.Properties) package offers multiple utility store methods that facilitate the storage of properties in either Text Format or XML ... Read More

In this article, we will see what are the possibilities available to create thread-safe HashSet instances and see what will be equivalent to ConcurrentHashMap for HashSet. We will also look at the benefits and drawbacks of each approach. Before JDK8 we are not able to create a Thread Safe ConcurrentHashMap because  java.util.concurrent package in JDK8 does not provide a class named ConcurrentHashSet, two new methods were added that are discussed below. ConcurrentHashMap is the Map implementation that allows us to modify the Map while iterating. The ConcurrentHashMap operations are thread-safe. ConcurrentHashMap doesn't allow null for keys and values. Ways to ... Read More