Spring Boot CommandLineRunner and ApplicationRunner
Introduction: In this quick tutorial, we’ll explore the two very popular interfaces in Spring Boot: CommandLineRunner and ApplicationRunner. One common use case of these interfaces is to load some static data at application startup. Though, I have seen such usages mostly for test data setup only. Both of them are functional interfaces with a run() […]
Introduction to Spring Boot
Introduction: In this tutorial, we’ll take a look at Spring Boot and see how it’s different from the Spring framework. We’ll also discuss various features offered by Spring Boot. What is the Spring Boot? Spring is a powerful framework when it comes to developing enterprise-level applications. It provides us with features like dependency injection along […]
Identifying Code Smells In Java
Introduction: As a software developer, it’s our responsibility to not only write code that works but rather write code that’s maintainable. Martin Fowler in his book Refactoring: Improving the design of existing code defines a code smell as: A surface indication that usually corresponds to a deeper problem in the system Refactoring is a process […]
SOLID Design Principles
Introduction: Robert C. Martin defined five object-oriented design principles: Single-Responsibility Principle Open-Closed Principle Liskov’s Substitution Principle Interface Segregation Principle, and Dependency Inversion Principle These together are popularly known as the SOLID principles. When designing an object-oriented system, we should try to stick to these principles wherever possible. These principles help us design a system that’s […]
Strategy Design Pattern In Java
Introduction: The strategy design pattern is a behavioral pattern in which we have multiple algorithms/strategies for achieving a task and which algorithm/strategy to use is left for the client to choose. The various algorithm options are encapsulated in individual classes. In this tutorial, we’ll learn to implement the strategy design pattern in Java. UML Representation: […]
Mediator Design Pattern In Java
Introduction: In this tutorial, we’ll learn about a behavioral pattern that promotes loose coupling between several objects communicating with one another. The idea behind the Mediator design pattern is to have a central object that encapsulates how a set of objects interact. In the mediator pattern, we extract all the relationships between different classes in […]
Chain Of Responsibility Design Pattern In Java
Introduction: In this tutorial, we’ll learn how to implement the Chain Of Responsibility Pattern in Java. The Chain Of Responsibility design pattern involves having a chain of objects that are together responsible for handling a request. When a client sends a request, the first handler will try to process it. If it can process it, […]
Command Design Pattern In Java
Introduction: In this tutorial, we’ll learn about the command pattern which is an important behavioral design pattern. It has some important applications like implementing undo/redo functionality in text editors. In the command design pattern, there’s a command object that sits between the sender and the receiver objects. The sender object can create a command object. […]
Observer Design Pattern In Java
Introduction: In this tutorial, we’ll talk about the Observer design pattern. There are two main aspects to the observer pattern – a Subject and the Observers. We use this pattern when our system has multiple objects, known as the observers, relying on the state of one particular object – the subject. All the observers register […]
State Design Pattern In Java
Introduction: In this tutorial, we’ll explore another popular behavioral design pattern – the State Design Pattern. The knowledge of state design pattern comes handy when we’re working with an object which can exist in multiple states. We should use it primarily when the behavior of an object depends on its current state. This pattern helps […]