SEARCH KEYWORD -- Must read


  A list of different CAPTCHA designs

Here is a list of website CAPTCHA designs which demonstrate all kinds of weird verification methods. By looking at these designs, as a website designer, you should distinguish which design is accessible and which is not.Is this human readable?What characters are in the picture?One moreWe will be crazy if we see theseOMG,What's the answer?IQ Test?Are you a normal person?You know how blind people read?ASCII PictureAre you an adult?3D verification codereCaptchaIt increase a new feature recently. It...

   CAPTCHA,Website design     2012-07-19 11:51:06

  Singleton Design Pattern in Java

Singleton is frequently used in applications where resource may be expensive to create and no instance specific state needs to be maintained. For example, when creating database connection, a singleton may be needed. Today we will share the famous Singleton design pattern in Java. 1. Definition Singleton design pattern is a design pattern that restricts the instantiation of a class to one object. It is one of the most well-known design patterns. 2. Application Singleton ...

   DESIGN PATTERN,SINGLETON,MULTITHREAD,JAVA     2020-04-11 02:16:28

  How to write your own DSL in Ruby

DSL(Domain Specific Language) is a language defined to fulfill some domain specific requirements to ease people's work. It can be used to define attributes and actions of a domain easily and cleanly. And it is often created based on some common observations or micro patterns of some domain. In Ruby world, there are quite a few places people can find DSL. For example, Ruby itself, Chef recipes. To create a class in Ruby, the traditional OOP way would look like. class User @name = nil @email =...

   RUBY,DSL,TUTORIAL     2017-03-04 09:40:34

  Be careful when running knife vault command

While using Chef, one would frequently use knife commands which are used to manage resources on the Chef server. One can list all nodes, data bags, vault items and many other stuff on the Chef server. In this post, we would cover one command which may need your attention when using it -- knife vault. On Chef server, one can store data to data bags which can be accessed by registered clients. These data bags usually store the data in plain text format. In some cases, one would need to store data ...

   KNIFE VAULT,KNIFE DATA BAG,CHEF-VAULT,CHEF     2017-08-19 00:26:54

  OpenLDAP Proxy -- Installation and configuration

After understanding what the configuration would be for an OpenLDAP proxy, it's time to explain the installation of OpenLDAP proxy and how to make it run. In this post, we will cover how to install OpenLDAP proxy both locally and using docker. Local installation The installation is quite easy, there are a few packages to be installed including the ldap server, ldap client and some utilities. Below steps are for CentOS, the instructions for other platforms should be similar with minor differ...

   INSTALLATION,CENTOS,DOCKER,OPENLDAP,OPENLDAP PROXY     2017-11-03 20:26:41

  Is Java Set ordered or not?

“Is Java Set ordered or not? ” is the most popular question asked when you interview for a Java Developer position. Many fail to answer it, and I have to admit I was one of the many. I have known the answer is “Yes and No” for a long time. No. HashSet is not ordered. Yes.TreeSet is ordered. If the interviewer continues with some follow up questions, I’m not confident that I know the answer then. Why is TreeSet ordered? Are there any other ordered S...

   ORDER,SORTEDSET,HASHSET,JAVA     2021-02-11 06:55:00

  How Java Application Developers Can Build Secure Internet Based Apps?

There are few compiled solution tested by experts to guide Java application development and maintenance team how they can start safe journey on Internet. Strong encryption, wise passwords, secure hardware are few of the tech tools that should be used by Java app development team to secure their Internet based apps.   The Internet is most amazing yet most risky platform where nobody knows either they are doing safe transaction on Internet or there is some dog watching out for data packets t...

   JAVA APPLICATION MAINTENANCE,JAVA APPLICATION DEVELOPMENT     2015-09-16 02:13:17

  How Charts Using Logarithmic Scale Provide Insight Into Your Business

In the dynamic realm of business, understanding data is as important as acquiring it. Analytical tools like charts, graphs, and tables aid in data comprehension. Among these tools, the necessary prowess of charts using logarithmic scale often goes unnoticed. Keep reading to know how this instrument can become a game-changer in your business analysis. Understanding Logarithmic Scale Before throwing light on its applications, it's crucial to understand the concept of a logarithmic scale. Unlike l...

   LOGARITHMIC CHARTS,BUSINESS SOLUTION     2023-12-09 02:34:17

  Python and PLC Communication

This article provides detailed steps on how to use Python to communicate with Schneider M221 and Siemens S7-1200 PLCs via Ethernet. Additionally, we offer a packaged Python PLC client library, enabling you to easily build your own SCADA control programs, such as Human-Machine Interfaces (HMI). The system overview is shown below: To check the project detail please refer to Python Physical PLC Communication Clients # Created: 2024/06/29 # Version: v0.1.3 # Copyright: Copyright (c) 2024 ...

   PYTHON,PLC,COMMUNICATION     2024-06-30 02:21:17

  How to use xargs command in Linux

What is the xargs command? The xargs command constructs and executes commands provided through standard input. It takes input and converts it into command arguments for another command. This functionality is particularly useful in file management and can be combined with commands like rm, cp, mkdir, and others. Using the xargs command When used alone, the xargs command prompts the user to enter a text string and then passes it to the echo command. This example demonstrates the input provided an...

   XARGS,LINUX     2023-11-17 11:19:41

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