How to check the JDK version of a class file

  • 17 March 2020
  • ADM

When running a Java application it is mandatory that the JRE version to match or to be higher that the JDK version used to compile the application.

You will get the "Unsupported major.minor version 52.0" error when trying to run an Java 1.8 application using a lower version of Java.


XML and HTML sitemap file in SEO

  • 16 February 2020
  • George

The sitemap's a file place on your website that will enable Google and other search engines to crawl better and understand the structure of the site. Sitemaps also tell search engines which pages on your site are most important. It's a binder of your website's content.


Robots.txt File in SEO

  • 13 February 2020
  • George

A robots.txt file tells search engine crawlers which pages or files the crawler can or can't request from your site. This is used mainly to avoid overloading your site with requests; it is not a mechanism for keeping a web page out of Google. To keep a web page out of Google, you should use noindex directives, or to password-protect your page.


How to use JSON Object in JavaScript

  • 06 February 2020
  • ADM

JSON is part of JavaScript programming language and is the main choise when it comes to data manipulation in JavaScript.

JSON is used from storing data, transfering data between client and server to configuring data.


How to fix apt lock-frontend error in Ubuntu

  • 24 August 2019
  • ADM

How to fix the E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) error.


How to get the dimensions of an image in Golang

  • 20 June 2019
  • ADM

Here are two simple methods to get the dimensions of an image in Golang: using image.DecodeConfig method if the image is not already loaded and image.Decode method is the image is loaded.