A list of Java topics at OpenGenus IQ

NullPointerException in Java

Any developer beginning their Java programming journey will inevitably come across a certain error: the NullPointerException. The NullPointerException is one of the most common errors encountered by beginner programmers when dealing with objects in Java.

Java

Hibernate Annotations

We can configure hibernate through Java configuration or XML configuration and the mapping details can be provided through XML or Java Annotations.

Java

Hibernate Inheritance Mapping

In this article, we are going to learn various strategies of inheritance mapping that hibernate implements to deal with Inheritance Object-Relational Impedance Mismatch.

Java

CRUD operation using hibernate in MySQL database

In this article, we are going to learn how to develop an application that performs the CRUD operations in MySQL database using hibernate. Here we will develop a command line application but the same procedure can be used to develop any other type of application like GUI, webapp etc.

Java

Linked Hash Set in Java

In this article, we will understand the LinkedHashSet Class which has been included in java.util since version 1.4.

Java

Caching in Hibernate

This article explains the basics of caching with Hibernate for default first-level cache and optional second-level cache, provides an extensive overview of general caching concepts, and includes example configurations of second-level cache.

Java

Mappings in Hibernate

This article explains and shows examples of mapping of relations between entity classes in application to relationships between database tables, including standard to SQL databases one-to-many, many-to-one, one-to-one, and many-to-many relationships in Hibernate.

Java

Basics of Hibernate (architecture + example)

Hibernate is a Java framework that maps Java classes and types into the relational databases, which solves problems of "paradigm mismatches". This article explains the basics of Hibernate and provides a simple example with the MySQL database.

Java

API requests in Java

This article shows and explains the techniques to run API requests from Java applications, examples applied for GitHub REST API, GitHub GraphQL API, and public web services for SOAP API.

Java

Download webpage in Java [5 methods]

There are multiple techniques and approaches to automating the process of acquiring information from the web resources, both for the simplest tasks and for advanced work automation. In this article, different solutions are explored together with the pros and cons.

Java

Type Conversion in Java

This article explains the basics of type conversion in Java, as well as potential problems to be aware of.

Java

Static Initialization Block in Java

We all must the idea of the Constructor in Java. But the difference is, the Static Initialization Block is a set of instructions that are run only once when the class is loaded into memory.

Java

Anonymous Class in Java

We know that Java language mainly follows the OOPs concept (From Java 1.8, we get functional programming.). So there is no anonymous function in Java. But we can create Anonymous objects by extending the concept of the inner class.

Java

Control Flow in Java

Java provides users with certain statements that facilitate them to control the flow of their program. Such statements are called Control Flow Statements.

Java

Different ways to terminate program in Java

Generally, Java programs terminate when they reach the end of the program, but there may be times when we need to know how to terminate a program when a certain condition is met or an exception occurs.

Java

Interview Questions in Java (MCQ)

In this article, we have presented several Interview Questions in Java (MCQ) covering all important topics in Java. These questions are frequently asked in Coding Interviews and you must attempt these questions.

Java

What Java Programmers Should Learn In 2021?

Insanely growing demand for programmers comes with more and more competition in the field, and that ends up in "survival of the fittest". Even if you're a talented Java programmer already, there is always room for improvement.

Software Engineering

TreeSet in Java

TreeSet is created using the implementations of the SortedSet interface in Java and it uses Tree for storage.

Software Engineering

StringBuilder in Java (java.lang.StringBuilder)

StringBuilder is a standard library class in Java which can be used in handling string data and is alternative to String Buffer and String data type.

Software Engineering

Design Graph using OOP concepts in Java

You are going to learn to design and implement the graph data structure using OOP (Object Oriented Programming) Concepts. We will implement in Java but the ideas are applicable in any language.

Algorithms

Applications of Hash Map

HashMap in java.util package implements the Map interface in java collection based on Hashtable. There are three main applications of Hash Map: Priority Queues, Dijkstra's Algorithm and Topological Sort.

Software Engineering

Linked List Implementation in Java

We learn how to implement and design Linked List in Java using Object Oriented Programming (OOP) concepts. We have provided the complete Java implementation of Linked List.

Software Engineering

Scope of Variables in Java Programming

Scope of a variable in Java defines how a specific variable is accessible within the program or across classes. It is defined by the use of private, protected and public.

Software Engineering

Chrome Dinosaur (T-Rex 🦖) game with Processing in Java

We have designed and developed the Chrome dinosaur game (T-Rex game) and implemented it in Java using Processing.

Software Engineering

String Pool in Java

In this article, I have explained the String Pool in Java and how to implement it in Java programming. I have covered basic concepts of this topic. Also, I have explain the diagram.