All thing coding
I wrote past few posts based on my notes from The Go Progamming Language by Donovan. In this article, we will try to make a go serverand expose rest APIs to read an write values from MySQL database. We will assume that your mySQL server is running at 3306 port in your local computer. net/http... Continue Reading →
Problem Statement Given n - bytes, implement a file system that supports following actions: Create File Update File Read File Delete File If you want a good start point for a small low level design problem, this post on designing a ride hailing service might be a good start. Demystifying Problem Statement When the problem... Continue Reading →
You might want to read the previous post in the series. Composite types created by combining the basic types like int, float etcetra. Arrays An array is a fixed length sequence of zero or more elements of particular type Because of the fixed length constraints, Arrays are rarely used in Go if "..." appears in... Continue Reading →
You might want to browse the previous post on this series. Integers Go provides both signed and unsigned integer type There are four different size of signed integer type; 8, 16, 32, 64 bits, represented by int8, int16, int32 and int64 Similarly there are four different size of unsigned integer types; 8, 16, 32, 64... Continue Reading →
Names The name of go functions, variables, constants, types and packages abide by following rules: Name begins with a letter or underscore Name can have any number of additional letters, digits as well as underscores Case in name matters; list and List are two different names Go has 25 reserved words like if, map, package,... Continue Reading →
Motivation for Completable Future Remember the guy Future? One which used to do tasks for us in a separate thread and return a future object where we can get the result. Let's refresh the memory with a small code snippet showing Future at work. ExecutorService executorService = Executors.newFixedThreadPool(5); Callable customer = () -> { return... Continue Reading →
Prerequisite If you don't know about GraphQL, this link is a good place to start. This article would assume that reader has basic knowledge of REST as well as Java. Mutation Drawing comparison from REST, any verb (e.g. GET, POST, PUT etc) are able to do server changes. But as convention, we use POST to... Continue Reading →
Introduction Assume that we have been given following mockup screens: A possible rest implementation would have following APIs: GET /car/{id} Response: { "id" : "car1", "carNumber" : "KA01HK", "driverId" : "12" } ------------------------------------- GET /driver/{id} Response: { "id" : "12", "firstName" : "Harsh", "lastName" : "Vardhan" } But! The first screen only wanted car number... Continue Reading →
We will use Java as programming language. This project will try to cover the following requirements. We will try to first define entities and then services. We will also build class diagram as we proceed as I don't want to bombard with a picture fill of random boxes and arrows at the end. If you... Continue Reading →
Problem Statement: Make a console based java application which support CRUD (Create, Read, Update, Delete) operations for e-commerce domain. Application should be able to support following features: Any user should be able to sign up, log in and log out. Admin should be able to add, update and delete products. Logged in user should be... Continue Reading →
The Null Pointer Exception 