Mar 1, 2021Notes from MongoDB Basics CourseDatabase is a structured way of storing to store and get the data. While relational databases do it in rows and columns of tables, NoSQL databases still structures their data but do it without using tables. …Mongodb5 min readMongodb5 min read
Feb 26, 2021RabbitMQWell, let’s say we have a distributed system and services. A simple way to enable communication between those services is to make them call each other directly. This is called RPC-style communication. RPC stands for remote procedure call. We know the address (URL or IP Address) of the service we…Rabbitmq3 min readRabbitmq3 min read
Feb 24, 2021Asymptotic analysis of algorithmsAlgorithm is a finite sequence of well-defined, computer-implementable instructions, typically to solve a class of problems or to perform a computation, and as anything else, we need a standard way to measure the performances of these algorithms to decide which ones to use in our programs. In order to compare…Asymptotic Notation4 min readAsymptotic Notation4 min read
Feb 24, 20214 questions on Java 8 Streamsjava.util.stream (which was added in Java8) is composed of classes that enables processing stream of elements. 1.What is a stream? A stream is a flow of objects that we can apply methods on to create the results we want. As it was stated here, it is not a data structure…Java 83 min readJava 83 min read
Feb 24, 2021Daemon vs non-daemon threadsJVM (Java Virtual Machine) is the layer between Java application and operating system and its sole purpose is to execute any program that is compiled to Java bytecode. Whenever you run a Java application, an instance of JVM is created and when the application completes, the instance dies. How does…Java3 min readJava3 min read
Feb 23, 2021Mapping JSON to EntityLet’s say that you have a json file which you want to map to a table in the database in your application with Spring Boot First, in order to map this to a class, we need to create an entity. import javax.persistence.Entity; import javax.persistence.Id; import javax.validation.constraints.Size; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor…Spring Boot2 min readSpring Boot2 min read
Feb 23, 2021Let’s construct stuff w/ Java1. Constructors are code blocks that run every time a class is instantiated by using new keyword. 2. No argument constructor is called default constructor. 3. Every class has to have at least one constructor. If no constructor is given in the class definition, compiler will define default constructor for…Java2 min readJava2 min read
Feb 23, 2021Why so transient?When I was looking at the source code of ArrayList, I saw that the actual array that holds the data items was defined as I had no idea what transient meant. So I looked it up, but before explaining what transient means and why elementData in ArrayList is defined as…Java2 min readJava2 min read
