What it is

JHexViewer is a basic hex viewer Swing component, which can be used to create more complex hex viewers based on it.

A lot of effort was put into making it customizable and easy to extend, instead of forcing you to stay with a fixed implementation. Nearly everything can be changed e.g. rendering of the content, Swing UI, layout of the rows etc.

It wasn't the goal to create a feature rich hex viewer as there are many existing tools out there. Instead I tried to focus on the core of a small hex viewer which builds the foundation for an easy to customize hex viewer.

Main goals were:

• to make it easy to customize and extend
• content is drawn using the Java 2D API to make it as customizable as possible
• complete exchangeable Swing UI
• write code that can be easily modified

Features

• Instant opening regardless of file-size
  • currently only the first 50MB are displayed
• Drag'n'Drop to load files
• Context menus
• Styleable row layout
  • insets
  • padding and spacing between bytes
  • byte grouping
    • display 1, 2, 4, 8 or 16 bytes as columns
• Styleable row rendering
  • use alternating colors
  • render certain bytes in different colors to highlight them
  • overwrite rendering of the background
  • overwrite rendering of the foreground
• Styleable highlighter
  • use different highlighters to mark ranges of bytes
  • overwrite the selection highlighter
• Custom themes
  • create custom themes to adjust the look of the hex viewer
• Custom Swing UI
• Many entry points to overwrite certain functionalities
  • painting of the areas (Area#setPainter)
  • used colors (Area#setColorProvider)
  • formatting of the displayed bytes and offset addresses (Area#setValueFormatter)
  • the caret (JHexViewer#setCaret)
  • the highlighter (JHexViewer#setHighlighter)
  • ...

Controls

Files can be loaded by drag and drop.

• Action keys
  • caret actions
    • to move the caret (arrow keys)
    • to start/expand a selection (mouse and arrow keys)
    • select all (crtl + 'a')
  • font actions
    • increase font size (crtl + '+')
    • decrease font size (crtl + '-')
  • switch focus between areas (tab)
  • repack window (useful after increasing/decreasing the font size) (crtl + 'r')

Build the project

Requires Maven and Java 8 or higher to build.

To build the maven project, run one of the following mvn commands from the command line. The command should be executed in the directory which contains the relevant pom.xml file.

Compile and run:

mvn -q compile exec:java

Compile and create executable jar file:

mvn -q compile assembly:single