The Aggregator design pattern in Microservice architecture is a design pattern used to compose a complex service by aggregating the responses of multiple independent microservices. It's also one of the essential Microservices Design patterns along with SAGA, CQRS, and Event Sourcing. This pattern is proper when a client request requires data or functionality distributed across multiple microservices. It can improve the performance and scalability of the system by allowing each microservice to focus on a specific task and reducing the workload of a single microservice. In this article, we will discuss how the Aggregator Microservice Pattern can be implemented in Java using various approaches, such as asynchronous communication, synchronous communication, or a combination of both. We will also provide examples of code to illustrate each approach.
Difference between VARCHAR and CHAR data type in SQL Server? [Explained]
Hello all, today, I am going to share an interesting SQL Server interview question, which will not only help you in your interview but also in your day-to-day work. It explains one of the critical concepts of SQL Server, the difference between VARCHAR and CHAR data type. I am sure, you all have used both of them numerous times but because it's so common many of us ignore the difference between them and when asked to choose between VARCHAR and CHAR on interviews, they fail to give a convincing reason. The difference is not just significant from an interview point of view but also from a robust database design because an incorrect choice of data type not only limit what kind of data you can put on but also waste precious space and makes your query slower, particularly when you have to deal with the massive amount of data.
What is window function in SQL with Examples? How and when to use them?
Hello folks, if you are wondering what is window function and what problem does it solve then you have to the right place. In this article, I would be explaining the windows functions with examples, how it works, and when you need to use it. Firstly what is a Window Function in SQL? A window function performs a calculation across a set of table rows that are similarly related to the current row. The current row is the row in which function evaluation occurs. This is comparable to the type of calculation that can be done with an aggregate function. But unlike regular aggregate functions like sum, avg, max, and min, that perform operations on an entire table.
What is API Gateway Design Pattern in Microservices? With Examples
Hello guys, API Gateway Design Pattern is a pattern that has emerged as a popular solution for managing APIs in a microservices architecture. As the number of services in the architecture increases, it becomes challenging to manage the APIs and handle requests from external clients. To address this challenge, API Gateway Design Pattern provides a single entry point for all the APIs in a microservices architecture. In the past, I have shared several Microservices design patterns like e Event Sourcing, SAGA, Database Per Microservices, CQRS, API Gateway, and also shared best practices to design Microservices and in this article, I am going to talk about the API Gateway Design Pattern, and how you can implement in Java using Spring Cloud Framework (Spring Cloud Gateway).
Asynchronous Messaging In Java? JMS, Kafka, and RabbitMQ Examples Tutorials
Hello fellow Java developers? Are you tired of those pesky synchronous messages clogging up your code like old grease in a drainpipe? Fear not, because today we're talking about asynchronous messaging in Java – the ultimate solution for decoupling your processes and improving the performance of your applications. But before we dive into the juicy details, let's start with the basics. What is Asynchronous Messaging? Asynchronous messaging is a method of communication between two or more processes like Microservices, where the sender sends a message and doesn't wait for a response before continuing with its own tasks. This is in contrast to synchronous messaging, where the sender must wait for a response before continuing.
What is CQRS Pattern in Java Microservices? Command Query Responsibility Segregation Example Tutorial
Hello guys, if you are wondering what is CQRS pattern and when and how to use it in your Microservices then you have come to the right place. CQRS is one of the 10 essential Microservice pattern and can be used when your application is either read heavy or write heavy and reading and writing requirement are very different. It aims to separate your app into two parts, command part which writes data and query part which read data and that's how it allows you to develop, scale and optimize them separately. It's also one of the popular Microservices Questions and if you are preparing for interviews, you should prepare this pattern as well. Earlier, I have explained SAGA Pattern and Database Per Microservice pattern and in this article I will explain CQRS pattern, when to use it and what problem does it solve.
How To Implement Security in Microservices Architecture
Hello guys, if you are wondering how to secure your Microservices, like put authentication and authorization then you have come to the right place. Security is a critical aspect of any software architecture, and microservices architecture is no exception. With its distributed and decentralized nature, microservices architecture presents unique security challenges that must be addressed to ensure the integrity, confidentiality, and availability of the system.In this article, we will discuss some best practices for implementing security in microservices architecture.
SAGA Design Pattern In Java Microservices with Example
Hello guys, if you want to learn about SAGA Microservice design pattern then you have come to the right place. SAGA is one of the 10 essential Microservice Design Patterns I have shared earlier and it solve a critical problem related to distributed transaction. But, before we get to the different examples that will teach you all about SAGA microservice design patterns in Java, let me tell you a bit more about what it really is. A microservice-based application is basically a distributed system. The overall system consists of multiple minor services, which provide the overall application functionality. This architectural style offers numerous benefits as well as several limitations. SAGA Pattern is also one of the popular Microservice interview question and if you are going for interview, it make sense to learn and understand this design pattern in depth.
What is Event Sourcing Design Pattern in Java Microservices? Example
Hello Java programmers, if you are tired of constantly trying to keep track of your application's current state using a traditional relational database then the Event Sourcing pattern might be just what you need. Event Sourcing is a popular pattern in Microservice architecture that allows services to persist and query the state of an application using a sequence of events instead of storing the current state. This pattern has gained popularity because it helps to build complex systems with a clear audit trail and support for long-term scalability. By storing a sequence of events, rather than just the latest state, developers can reconstruct the application state at any point in time, even after failures or bugs. It's also one of the 10 essential Microservice patterns I have shared earlier and it's one of the top 3 along with Saga and CQRS patterns which we have seen in my earlier articles.
8 Examples of Primitive Data Types In Java (int, long, boolean, float, double, byte, char, and short)
Hello guys, Data types are first few things you should learn when you start learning a programming language and when it comes to learn Java, there are 8 primitive data types which you should know. These are divided into three categories, numeric, text, and boolean values. Numeric data types can be further divided into two like natural numbers and floating pointing numbers. But, Before we get to a list of the 10 examples of primitive data types in Java, let me tell you a little bit more about what the primitive data types are. There are essentially 8 primitive data types in Java. They are int, byte, short, long, float, double, boolean, and char. The primitive data types are not considered objects and represent raw values. These primitive data types are also stored directly on the stack.
10 points on TCP/IP Protocol, Java Programmers should Know
TCP/IP is one of the most important protocol as its backbone of HTTP, internet and most of the communication happens today. It's also important from technical interview perspective, you might have already seen difference between TCP and UDP multiple time during interviews ( I have seen). I believe every programmer, not just Java developer should know what is TCP/IP protocol? How it works and the below points I am going to mention. These are basic points and most of you already know but during Interview I have found many developers who doesn't really know what TCP/IP offers and how it works and what are the pros and cons of TCP/IP protocol. That's where, I think this article will help you. Anyway, let's jump into technical details now.
What is try with resource in Java? Example tutorial
In Java we normally use resources like file, network connection, socket connection, database connection etc ,dealing with resources is not a difficult task but what if after using the resources programmers forget to close the resources. As we know in Java everything is Object so if we forget to close or shut down the resource its responsibility of GC that will recollect it when its no longer used but we can reduce resource exhaustion by explicitly closing the resources as soon we done with our job with the resources. Some resources like database connection are very precious and would surely run out of resources if waited for finalization. Many database servers only accept a certain number of connections so if forget to close properly will create problem.
How to replace Anonymous Class to Lambda Expression in Java 8? Example Tutorial
Hello guys, you may be thinking why I am talking about Anonymous class now when many Java programmers have already switched to Java 8 and many have already moved on from Anonymous class to Lambda expression in? Well, I am doing it because I am seeing many Java programmers who find it difficult to write and read code using lambda expression in new Java 8 way. It's also my own experience that if you know the problem first, you can better understand the solution (lambda expression). Some of you might remember, the opening scene of MI 2 (Mission Impossible 2), when Nekhorovich says to Dimitri that "Every search for a hero must begin with something that every hero requires, a villain. Therefore, in our search for a hero, Belairiform, we created the monster, Chimera".
Java FileReader + BufferedReader Example
There are multiple ways to read a file in Java e.g. you can use a Scanner as we have seen in the last example, or you can use the BufferedReader class. The advantage of using a BufferedReader to read a text file is speed. It allows faster reading because of internal buffering provided by BufferedReader. Other Reader classes like FileReader access the file or disk every time you call the read() method but BufferedReader keeps 8KB worth of data in its internal buffer which you can read it without accessing the file multiple times. It's loaded when you access the file the first time for a subsequent read.
10 Examples of print(), println() and prinf() methods In Java - PrintStream
Hello guys, if you are working in Java or just started with Java then you have must come across statements like System.out.println("Hello world") to print something on console or command prompt. This is actually the first statement I wrote in Java when I started programming and at that time I didn't realize how it work and what is System and PrintStream class and what is out here but now I know and I am going to explain all this to you in this article, along with PrintStream class and its various print methods like print(), println() and particularly printf() to print various objects in Java. But, Before we get to the 10 examples of Printstream printf() in Java, let me tell you a little bit more about what exactly Printstream is.
Chain of Responsibility Pattern in Java? Example Tutorial
Hello guys, if you have been doing Java development then you must have come across design pattern, tried and tested solution of common software problem. In the past, we have looked at several popular Object Oriented Design Patterns in Java like Adapter, Decorator, State, Strategy, Template, Composite, Command, Observer, Factory, Builder, Visitor etc, and today I am going to talk about Chain of Responsibility design pattern in Java. The Chained or Chain of Responsibility Pattern is a design pattern that allows a request to be passed along a chain of objects until it is handled by one of the objects in the chain. This pattern is helpful for situations where it is not known in advance which object in the chain should handle the request, or where the request needs to be handled by multiple objects in the chain.
Top 10 Projects to Learn Front-End Web Development
Hello guys, If you are looking for ways to learn Front-End Web Development, you have come to the right place because all of what you want is right here. You just have to keenly go through this article till the end and you will get what you need. Front-end web development is a popular field that involves creating the user interface and experience of websites and web applications. It is an ever-evolving field that requires developers to stay up-to-date with the latest tools, technologies, and trends. One of the best ways to learn front-end web development is through hands-on projects. In this article, we will explore the top 10 projects that can help you learn front-end web development and enhance your skills in HTML, CSS, JavaScript, and other related technologies.
How to use @JsonCreator and @JsonPropertOrder Jackson JN Annotation in Java? Examples
Hello guys, if you are dealing with JSON in Java then you may have come across Jackson, one of the popular JSON library in Java. Jackson provides many cool annotations to serialize and de-serialize JSON to Java object and vice-versa. Earlier, I have showed you 3 ways to convert JSON to Java object and 10 free Jon Tools for programmers and in this article, we will deep dive into two popular Jackson annotations @JsonCreator, @JsonProperty, and @JsonProperOrder. But, Before I tach you exactly how you can use the @JsonCreator annotation, let me briefly tell you a bit more about what Java really is.
Top 5 Functional Interface Every Java Developer Should Learn
Hello guys, functional interface in Java are an important concept but not many developer pay enough attention to them. They learn lambda and method reference but the functional interface from java.util.function package. While its not really possible to learn all the functional interfaces on that package but you can learn a few more commonly used ones like Predicate, Supplier, Consumer etc and that's what you will learn in this article. But, before we get to the top 5 functional interfaces that every Java developer should learn, let me tell you a bit about what Java really is.
Difference between Class and Object in Java? Example
Class and Object are two pillars of Java and any Object oriented programming language. There are multiple ways you can describe Class in Java, I will start with how I remember class from my college Days. That time, I used to remember that "A class is a blueprint to create object" and that's how I answer during viva or exam. While I know what is a blueprint, I didn't really understand what a class can do. Later, when I started coding, I learned about data types like int data type to hold integer values. String data type to hold text values.
Subscribe to:
Posts (Atom)