PDF Merger

Table of contents

• description
• file selection
• save path configuration
• technologies used

Description

PDF Merger, unsurprisingly, merges multiple PDF files into one.

It’s an app that I developed back in 2022, when my only option to merge PDFs was to use web-based tools hosted by strangers. I was very paranoid that they might secretly save my files in a remote database somewhere 😬😬, so I decided to build my own tool.

Features

PDF merger has one simple goal: merging PDF files. As part of this, it supports a couple of features:

• Selecting files to merge
• File path configuration of new PDF

File selection

Users can select the source PDF files to merge. The GUI includes a “Select files” button that invokes the operating system’s native file browser.

File selections can also be reset with the “Reset selection” button.

Save path configuration

Users can freely choose the directory/folder to which their new PDF will be saved. Again, this will bring up the OS’s file browser where the user can select a directory as the destination. There is a default path configured, so this is optional.

The user can then choose a name for the new PDF file, then click “Merge!“.

Technologies used

This is a Java-based desktop GUI application. The entire app was written in Java, with the GUI being implemented using JavaFX.

I followed object-oriented principles in creating this app:

• Encapsulation: Features like the file merger and save file selector were encapsulated into their own classes

• Abstraction: The internal logic/implementation of file merging was abstracted away from clients by utilizing private attributes/methods, which decoupled the public API from its implementation details

• Inheritance: My application extended the Application superclass from JavaFX, saving me from having to develop my GUI entirely from scratch 😮‍💨

• Polymorphism: By interacting with thrown exceptions through the Throwable supertype, I was able to invoke polymorphism at runtime by having each exception class implement the logging method differently

Furthermore, PDF merging was executed using Apache’s PDFBox open-source library.

Aside: It was through this project that I realized the importance of the open-source ecosystem! Having just started out in software development, it would’ve taken me a very long time to implement this logic all from scratch.