java-diff-utils

Intro

Diff Utils library is an OpenSource library for performing the comparison operations between texts: computing diffs, applying patches, generating unified diffs or parsing them, generating diff output for easy future displaying (like side-by-side view) and so on.

Main reason to build this library was the lack of easy-to-use libraries with all the usual stuff you need while working with diff files. Originally it was inspired by JRCS library and it's nice design of diff module.

This is originally a fork of java-diff-utils from Google Code Archive.

Examples

Look here to find more helpful informations and examples.

These two outputs are generated using this java-diff-utils. The source code can also be found at the Examples page:

Producing a one liner including all difference information.

This is a test senctencefor diffutils.

Producing a side by side view of computed differences.

original	new
This is a test senctence.	This is a test for diffutils.
This is the second line.	This is the second line.
And here is the finish.

Main Features

• computing the difference between two texts.
• capable to hand more than plain ascci. Arrays or List of any type that implements hashCode() and equals() correctly can be subject to differencing using this library
• patch and unpatch the text with the given patch
• parsing the unified diff format
• producing human-readable differences
• inline difference construction
• Algorithms:
  • Myer
  • HistogramDiff using JGit Library

Algoritms

• Myer's diff
• HistogramDiff

But it can easily replaced by any other which is better for handing your texts. I have plan to add implementation of some in future.

Changelog

• Version 2.2-SNAPSHOT
  • Added chunk to support surroundings of differences
  • Verify also looks at surroundings
  • Deltas now can proof if another delta change the same chunk
  • Chunks now can proof if another chunk change the same positions
• Version 2.1-SNAPSHOT
  • included checkstyle source code conventions
• Version 2.0
  • switch to maven and removed other artifacts
  • changed groupid to com.github.java-diff-utils due to different forks at github
  • updated maven plugins
  • JDK 1.8 compatibility, sorry if you have to stick with older versions
  • support for inline merge
  • restructured packages heavily
  • changed API
  • changed Algorithm to provide only cursor positions
  • integrated JGit (Eclipse Licensed) to provide HistogramDiff to gain speed for large datasets
  • removed all kinds of helper classes in favour of new JDK 8 function classes like Predicate
• Version 1.2
  • JDK 1.5 compatibility
  • Ant build script
  • Generate output in unified diff format (thanks for Bill James)

Source Code conventions

Recently a checkstyle process was integrated into the build process. JSqlParser follows the sun java format convention. There are no TABs allowed. Use spaces.

public static <T> Patch<T> diff(List<T> original, List<T> revised,
	BiPredicate<T, T> equalizer) throws DiffException {
	if (equalizer != null) {
		return DiffUtils.diff(original, revised,
				new MyersDiff<>(equalizer));
	}
	return DiffUtils.diff(original, revised, new MyersDiff<>());
}

This is a valid piece of source code:

• blocks without braces are not allowed
• after control statements (if, while, for) a whitespace is expected
• the opening brace should be in the same line as the control statement

To Install

This jar is not yet to get at maven central.

Just add the code below to your maven dependencies:

<dependency>
    <groupId>com.github.java-diff-utils</groupId>
    <artifactId>diffutils</artifactId>
    <version>2.0-SNAPSHOT</version>
</dependency>