Execute multiple curl requests in parallel

This tutorial will demonstrate how to execute multiple curl requests in parallel, at the same time. We will use xargs command of linux or UNIX like operating system. What does xargs command do in Linux? xargs is a great command that reads streams of data from standard input, then generates and executes command lines; meaning it can take a command’s ... Read More »

Set globally multiple header parameters in Swagger


In this article, we will learn how to set multiple header parameters globally in a Spring Boot application. Why do we need it? There are cases where we want the client to send multiple header parameters along with the one auth token, these parameters may be useful to validate the token or may be required along with the token to ... Read More »

AES Encryption Class Compatible with Java and PHP


Most of the time we come across a scenario where we want something that is encrypted in Java, that requires to be decrypted by PHP or vice versa. In this article, we will build a Java class that encrypt-decrypt the input string and the same class in PHP which also encrypt-decrypts the input string and produces the same result. AES ... Read More »

Useful Linux Commands

Check the battery’s status via the terminal Time the machine has been running Display disk usage information Display information about the CPU List network interfaces Display information about your kernel release Display System Hardware information Reboot the system Shutdown the system at a specific time Start/Stop/Restart a service Checking a service status Enabling/Disabling a service to run at boot time ... Read More »

CVE-2022-22965 SpringShell Vulnerability


SpringShell is a new Spring Framework Remote Code Execution (RCE), aka CVE-2022-22965, security vulnerability. Essentially all versions of the Spring Framework, including 5.3.0 to 5.3.17, 5.2.0 to 5.2.19, and older, unsupported versions are vulnerable. Check if your Spring application is Vulnerable? If you are using JDK 9 or higher. If you are using Apache Tomcat as the Servlet container. If your ... Read More »

Reactive MongoDB Auto Increment ID Using Spring WebFlux

reactive spring

In this tutorial, we will learn how to generate an auto-incrementing sequence id in our Spring WebFlux and Reactive MongoDB project. First we will create our model class Models In the above Employee collection class, we have to give a sequence name for this collection, which is annotated with @Transient. We will have to give a separate sequence name in ... Read More »

Spring WebFlux & Reactive MongoDB

reactive spring

In this article, I will be providing a step-by-step guide to developing the Spring WebFlux RestFul API using a reactive programming approach along with Reactive MongoDB. Spring WebFlux is the spring framework step towards the reactive programming model. It uses Reactor to support the Reactive Streams API and runs on the netty server. Here we will be using Reactive MongoDB ... Read More »

How to kill Linux process by port

Below is the command which will kill all the processes which are using a particular port. For example, say we want to kill the process which is using port 9091 in our Linux server. Read More »

Spring4Shell Vulnerability – Spring Core RCE Vulnerability


Security researchers have found a new vulnerability around Spring Core, which may cause serious damage to millions of applications over the internet. This vulnerability is been said that exists in Spring core with java version JDK9.0 and above. The bad news is no patch has been released yet by the Spring. But there are some strategies to mitigate the attack. ... Read More »

Get Client Remote Address from ServerExchange in Spring WebFlux and whitelist IP

reactive spring

Below is the Spring WebFlux code to fetch the client Remote Address from the ServerExchange object. Say, we have a scenario wherein we have to check if the API request is coming from the authorized IP address list, in the web filter we will fetch the IP address of the client and will match with the set of given IP’s ... Read More »