db-afk / keyboard-encoding

Overview

The goal of this exercise is to write a stand-alone simple Java application that performs simple encoding

Part of your application is a set of 3 character transform functions. These transformations will be applied over a 4 rows x 10 columns section of a standard QWERTY keyboard as highlighted in the picture above. The four rows start with 1, q, a, z and extend to 0, p, ;, / respectively.

There are three types of transformations:

Horizontal Flip (H)

This transformation will flip all rows of the keyboard horizontally.

Example, doing a single horizontal flip will result in:

• 1 will swap with 0
• 2 will swap with 9
• (and so on)

Vertical Flip (V)

• This transformation will flip all rows of the keyboard vertically.

Example, doing a single vertical flip will result in:

• 1 will swap with z
• q will swap with a
• 2 will swap with x
• (and so on)

Shift (#)

• This transformation should take in an integer N and perform a linear shift of the keyboard. Each key should shift N places to its right if N > 0 (and likewise to the left if N < 0). If a key would move past its current row then it should shift into the row below, and so on.

For example, for N = 5:

The last five keys(nm,./ would move into the first 5 places of the top row, the 12345 would move 5 places to the right, 67890 would move to the start of the 2nd row, and soon). Likewise, left-shifting keys past their current rows would shift them back into the row above. Therefore, a single right, and a left shift would produce the same keyboard.

How to use the application

This application is created solely using Maven. Using Mavens mvn install command you can install projects into your Maven repository, so it can be used to compile other projects that depend on it.

This app has very little dependencies:

• junit-jupiter-engine and maven-surefire-plugin for unit tests
• commons-lang for some non-trivial Java operations.

The main class within the app is the Encoder it accepts the path to the text which is going to be encrypted and list of operations stored in comma-separated text file. To obtain the encoded text (based on operations listed in operation file) getEncodedText() should be call.