Hello There! Today, i’m going to explain a merchant acquiring system that i had designed in my previous company. What is acquiring bank? according to wiki, an acquiring bank (also known simply as an acquirer) is a bank or financial institution that processes credit or debit card payments on behalf of a merchant. Acquirers collaborate […]
Converting from byte[] (array) to hex string in Java
Hello there! I just wanted to share a small piece of code I wrote way back in 2011 when I was working at my previous company. Yep, that was ages ago 🤭. It’s a simple utility function I created to convert a byte[] into a hexadecimal String. Nothing fancy, but still useful even today! Its pretty simple code isn’t it? […]
Simple DateUtils Class in Java
In PHP, you can easily adjust dates — whether to move forward or backward — using a built-in function. By combining strtotime() with date(), you can format and modify dates effortlessly. Here’s a quick example: Difference In Java, you need to define which Object that need to be use for an output on each function or method. But […]
HTTP JSON POST in C/C++ For Thales CipherTrust Tokenization (CT-VL)
Hello There! When i get bored in Java or PHP, i do sometime explore new thing in C/C++. I usually wanted to know more in difference way of programming language. The goal of the code that i created is very simple, which only doing a few requirements like below. You can look and check, the […]
How to sign a jar file from your *.jks file
First, generate a RSA key for signing Second, sign the jar with jarsigner You can ignore : “warning : POSIX file permission and/or symlink attributes detected. These attributes are ignored when signing and are not protected by the signature.”
AES ECB encryption with padding and no padding in java language.
Hello there! When working with AES encryption in Java, one important thing to understand is how AES handles input length, especially when using ECB mode with padding and no padding. AES is a block cipher, which means it encrypts data in fixed-size blocks. For AES, the block size is always 16 bytes. Because of this, the input data must fit into […]
Error : Entry META-INF/LICENSE.txt is a duplicate but no duplicate handling strategy has been set.
Hello There! When you wanted to build a jar file from your code, you accidentally facing an error such like below : That is I because you haven’t set any duplicates Strategy in your build.gradle file. You need to add a 1 line code like below. So, the before code is : this is after […]