Knowledge Factory

In this article, we will show you how to develop a  REST-style web service with Go Language and MYSQL. These are APIs that Spring backend App will export: GET all User's        :   /users GET User by ID     :   /users/{id}  POST User             :   /users PUT User               :   /users DELETE User       :   /users/{id} Technologies used: Go Language MYSQL Database gorilla/mux jinzhu/gorm gorilla/mux:  The gorilla/mux package provides request routing, validation, and other services. jinzhu/gorm:  The gorm is an ORM library for the Go language.GORM provides CRUD operations and can also be used for the initial migration and creation of the database schema. Final Project Structure: Let's start building the application Create database 'userdb': CREATE DATABASE userdb; Initialize the Go project: Initialize the Go project  using the following command go mod init rest-crud-api-go-lang Adding the modules required for the project: go get github.com/gorilla/mux go get github.c

Hello everyone, In this tutorial, we will learn h ow to add/subtract Hour, Minute, Second, Millisecond, Microsecond and Nanosecond to date in Go Language. The time package in Go language provides Add() function which  is used to add/subtract a duration to time t. Since duration can be represented in hours, minutes, seconds, milliseconds, microseconds and nanoseconds, The signature of the Add method is: func (t Time) Add(d Duration) Time Example 1: Go Program to add/subtract minutes. package main import ( "fmt" "time" ) func main() { //Current date and time dt1 := time.Now() fmt.Println( "Current date and time : " , dt1) //Adding 30 minutes dt2 := dt1.Add( 30 * time.Minute) fmt.Println( "After 30 minutes:" , dt2) //Subtract 3 minutes dt3 := dt1.Add(- 3 * time.Minute) fmt.Println( "Before 3 minutes:" , dt3) } Output: Example 2: Go Program to add/subtract seconds. package main import (

Hello everyone, In this tutorial, we will learn h ow to add/subtract days, months or years to a date in Go Language. The time package in Go language provides AddDate() function which is used to add/subtract years, months and days to time t.  The signature of the AddDate method is: func (t Time) AddDate(years int , months int , days int ) Time Example 1: Go Program to add/subtract days. package main import ( "fmt" "time" ) func main() { //Current date and time dt1 := time.Now() fmt.Println( "Current date and time : " , dt1) //Adding 3 days dt2 := dt1.AddDate( 0 , 0 , 3 ) fmt.Println( "After three days: " , dt2) //Subtract 400 days dt3 := dt1.AddDate( 0 , 0 , - 400 ) fmt.Println( "Before 400 days: " , dt3) } Output: Example 2: Go Program to add/subtract months. package main import ( "fmt" "time" ) func main() { //Current date and time dt1 := time.Now()

In Go Language, a string is a slice of bytes. The bytes of the strings can be defined in the Unicode text using UTF-8 encoding. UTF-8 is based on 8-bit code units. Each character is encoded as 1 to 4 bytes. The first 128 Unicode code points are encoded as 1 byte in UTF-8. For Example, package main import "fmt" func main() { text := "aπ" fmt.Println(len(text)) } Output: 3 Here the length of the String is 3 because, ‘a’ takes one byte as per UTF-8  ‘π’ takes two bytes as per UTF-8 So we cannot use for loop to iterate over all the characters of the string because  it will iterate over bytes and not characters. This means  it will iterate three times and the print value corresponding to a byte at that index. How to iterate over all the characters of the string in Go Language? Iterate over a string by runes  Iterate over a string by for-range loop Iterate over a string by runes Go allows us to easily convert a string to a slice of runes and then iterate over t

The RSA algorithm (Rivest-Shamir-Adleman) is a cryptographic algorithm that is used for specific security services or purposes, which enables public-key encryption and is widely used to secure sensitive data, particularly when it is being sent over an insecure network such as the HTTP. A public key is shared publicly, while a private key is secret and must not be shared with anyone. The following illustration highlights how asymmetric cryptography works: Example 1: RSA Encryption and Decryption with OAEP, package main //Required imports for Encryption & Decryption import ( "crypto/rand" "crypto/rsa" "crypto/sha512" "encoding/base64" "fmt" ) func main() { //3072 is the number of bits for RSA bitSize := 3072 //Generate RSA keys privateKey, err := rsa. GenerateKey(rand.Reader, bitSize) if err != nil { panic(err) } publicKey := privateKey.PublicKey //Your secret te