Knowledge Factory

Here’s an end-to-end example of integrating Spring Security with Spring LDAP for authentication in a Spring Boot  application. 1. Set Up Local LDAP Server To install and run an LDAP server locally, you can use Apache Directory Server or OpenLDAP . Here, I'll use Apache Directory Server (Apache DS) because it's easy to set up and works well with Spring Boot. 1.1. Install Apache Directory Server Download Apache Directory Server from the official site . Choose the latest version based on your operating system. Install Apache Directory Server : Extract the downloaded ZIP or tar.gz file to a directory of your choice. Open a terminal or command prompt and navigate to the directory where you extracted the server. Start Apache Directory Server : Run the following command to start the LDAP server: bin/apacheds .sh start For Windows, use bin/apacheds.bat start . Access the Apache Directory Studio (optional) for easier interaction with your LDAP server: Download Apache Directory Stud...

Here's a comprehensive Java String, StringBuilder, and StringBuffer Interview Guide with essential concepts and frequently asked interview questions for a fresher: Essential Concepts to Understand: String Class: Immutable : Once created, its value cannot be changed. String Pool : Optimizes memory by storing unique String objects. Operations like concatenation create new String objects rather than modifying the original. StringBuilder Class: Mutable : Can modify its content without creating new objects. Not thread-safe : It is faster in single-threaded contexts due to the absence of synchronization. Preferred when frequent string modifications (like appending or inserting) are required. StringBuffer Class: Mutable : Similar to StringBuilder but synchronized for thread safety. Thread-safe : Ideal when multiple threads may modify the string, but slightly slower due to synchronization. Commonly Asked Interview Questions and Answers: 1. What differentiates String , StringBuilder , a...

 Here is a list of 50 Spring Boot microservices interview questions with concise answers.  1. What are microservices? Microservices are a software architecture style where an application is divided into small, independent services that can be deployed, managed, and scaled individually. 2. What are the advantages of microservices? Scalability Independent deployment Flexibility in technology stack Fault isolation Easier maintenance and updates 3. What is Spring Boot? Spring Boot is a framework that simplifies the process of building and deploying Spring-based applications. It provides built-in features such as embedded servers, configuration management, and production-ready features. 4. What is the difference between Spring Boot and Spring Framework? Spring Boot simplifies the setup of Spring applications with embedded servers and auto-configuration. Spring Framework requires manual setup of configurations, application contexts, and server setups. 5. What are Spring Boot Starter...

To integrate Laravel with Google Cloud Storage for file upload, listing, downloading, and deleting, you can follow these steps: 1. Install Required Packages First, install the Google Cloud Storage package for Laravel. You can use google/cloud-storage and laravel/filesystem to handle cloud storage integration. Run the following command in your Laravel project: composer require google/cloud-storage Then, install the league/flysystem-google-cloud-storage package, which provides an adapter for Laravel’s filesystem: composer require league/flysystem-google-cloud-storage 2. Configure Google Cloud Storage Next, configure your Google Cloud Storage credentials. Create a Google Cloud Storage Bucket if you don’t have one already. Generate a Service Account Key from Google Cloud Console: Go to the Google Cloud Console . Navigate to IAM & Admin > Service Accounts . Create a new service account and assign it the Storage Object Admin role. Download the generated JSON key file. Store th...

To secure your Go (Golang) backend with Okta, you can integrate Okta's identity and access management system by leveraging OAuth 2.0 and JWT-based authentication. Below are the steps to set up this integration from scratch: Step 1: Sign Up for Okta Developer Account Go to Okta Developer and create a free developer account. After registering, create a new Okta Application that will represent your Golang backend service. Step 2: Create an Okta Application In your Okta dashboard, navigate to Applications and click Create App . Select Web as your platform and choose OAuth 2.0 as the authentication method. Take note of the Client ID , Client Secret , and Issuer URI , which will be required in the Go app for authentication. Step 3: Install Required Libraries Although Okta does not provide an official Go SDK, you can integrate Okta with Go using widely-used OAuth 2.0 and JWT libraries. Start by installing the necessary packages: OAuth2 for handling token-based authentication: go get...

  The answers to the questions below are waiting for you at the end of this blog. Keep reading to discover them! 1. Which of the following is true about Java bytecode? A. It can only be executed on the machine where it was compiled. B. It can be executed on any platform that has a compatible Java Virtual Machine (JVM). C. It can be executed on any operating system but only on specific hardware architectures. D. It needs to be compiled separately for each operating system and hardware architecture to run properly. 2. Given the following code: //1 //2 public class ExampleClass { public static void main ( String[] args ) { String message = "Hello, World!" ; System. out .println(message); } } Which two lines can be inserted at locations marked //1 and //2 ? A. import java.util.*; at //1 B. import java.lang.*; at //1 C. package example; at //1 D. package com.example; at //2 E. import java.lang.*; at //2 F. import java.util.*; at //2 3. Which ...

To create a simple CRUD application using Ktor (backend) and Vue.js (frontend), follow these steps: Backend (Ktor) Set up Ktor Project : In your build.gradle.kts file, add Ktor dependencies for HTTP, serialization, and PostgreSQL (or another database if preferred): plugins { kotlin( "jvm" ) version "1.8.0" application } dependencies { implementation( "io.ktor:ktor-server-core:2.2.2" ) implementation( "io.ktor:ktor-server-netty:2.2.2" ) implementation( "io.ktor:ktor-serialization-kotlinx-json:2.2.2" ) implementation( "io.ktor:ktor-server-sessions:2.2.2" ) implementation( "org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.0" ) implementation( "org.jetbrains.exposed:exposed-core:0.41.1" ) implementation( "org.jetbrains.exposed:exposed-dao:0.41.1" ) implementation( "org.jetbrains.exposed:exposed-jdbc:0.41.1" ) implementation( "org.post...