A list of Java topics at OpenGenus IQ

Understand Package in Java

Java package corresponds to the file system directory managing different code levels. In this post, we have explored packages in depth.

software engineering

Find the size of an object in Java

In Java, it is possible to get the size of an object using its instrumentation package using its premain mechanism and getObjectSize() function

software engineering

Basic Full Stack Calculator Project using DevOps tools

In this article, we will develop a basic calculator in Java using DevOps tools like Apache Maven as a build tool, GitHub for source code management, Jenkins for Continuous integration and deployment and Sonatype Nexus for Artifact repository management.

software engineering

How Java allocates memory to objects?

In Java, all objects have memory located in the heap space where Java's garbage collection constantly remove unused objects to make application memory efficient

software engineering

Java does not support goto

In Java, goto is a reserved word but it has not implemented in Java. Hence, we do not have a same goto keyword/ feature as in other languages like C and C++

software engineering

continue statement in Java

continue statement is a program flow control statement in Java. It is used to skip the current loop iteration and switch to the next loop iteration.

software engineering

Extend Java's type system with Generic Classes

Generics are a Java paradigm which extends the language's type system, allowing the development of less redundant code with an unnecessary amount of casting

software engineering

Java does not support Multiple and Multipath inheritance

In this article, we will look at the limitation set by Java on inheritance and how it cannot support Multiple and Multipath inheritance.

software engineering

Different types of Inheritance in Java

In short, Java does not support inheriting multiple classes and hence, does not support multiple and multipath inheritance. Java supports single, hybrid, hierarchical and multilevel inheritance.

software engineering

Using wrapper classes in Java

A Wrapper class is a class whose object contains a primitive data types. We can think this as a primitive data type with an additional layer which enables it is get benefits of a custom user defined objects in Java.

software engineering

Learn to use Queue in Java Collections Framework

In this article, we will take a look at how to use the Queue class in Java Collections library. This is useful as one can directly use queue without natively implementing it

software engineering

Building a basic Java Application using Apache Maven (Command Line)

Apache Maven is a Configuration oriented build tool used to build projects whose source code in written in Java. We create a basic Java project using Maven

software engineering

Working with Set in Java like a master

Set is a data structure that is used as a collection of objects. Java supports it through its Java Collection library.

software engineering

Write Custom/ User-defined exceptions in Java

Custom Exceptions: These exceptions are not defined in Java librairies, but can be defined by us to handle customized error situations. Example: Suppose, our banking transaction program should raise exception for debit from an account with zero balance

software engineering

Master the use of Constructors in Java

In Java, a constructor is a block of code similar to a method which is used to initialize objects. It is called when an instance of a class is created.

software engineering

Understand and use Static members in Java

In this article, you will learn What are static members in Java?, When to use them? and When they can be a problem? Static means only one copy exists for the entire class irrespective of the number of objects that exists for that class.

software engineering

Understanding and using Access Specifiers in Java

Access specifiers are utilities/ code features that restrict the access to a particular code feature or data depending upon the source of the code requesting the access. In Java, they are private, public, protected and default.

software engineering

Understanding Encapsulation in Java

Encapsulation is an object oriented programming (OOP) implementation technique where we are related data members in a single unit (class) and define member functions to allow indirect and restricted control from the user side.

software engineering

Understanding Classes and objects in Java

You will understand Why we need classes?, How to define and use classes in Java?, Structure of classes in Java along with constructors and access specifiers, How to use objects in Java? and Characteristics and attributes of objects along with comparing two objects

software engineering

Reading Data from Files in Java

We will explore 5 different ways of reading files in Java BufferedReader, Scanner, StreamTokenizer, FileChannel and DataInputStream. What is the role of encodings like UTF-8 in reading data in Java? Exception/ Errors you may encounter while reading files in Java

software engineering

Creating and resolving Deadlocks in Java

The term Deadlock refers to a situation in multithreading, where two or more threads are blocked forever, waiting for each other. In Java, we use synchronized keyword to make the class or method thread-safe.The keyword ensures that only one thread can access the resource at a given point of time.

software engineering

Switch Case in Java

A switch statement in Java allows an expression to be tested for equality against a list of values. Java SE 7 and later, the support for a String object is also available with switch case. We explore the basics of it like break, default statements and syntax rules

software engineering

Working with Strings in Java

In Java, strings are treated as objects of class String. Strings are immutable objects which means they are constant and cannot be changed once it has been created. How to create a string in Java? Does String class has a Constructor? How to compare Strings in Java? How to search a string in Java?

Java

Introduction to Java Server Pages (JSP)

JSP stands for Java Server Pages. It is a server side technology used for creating dynamic and platform independent web pages. JSP is the advanced version of Servlets.

Java

Map in Java

The java.util.Map interface represents a mapping between a key and a value. The Map interface is not a subtype of the Collection interface. Therefore it behaves a bit different from the rest of the collection types.