Sample Usage

Introduction

The all common operation of this library is available through static methods of DiffUtils object. These methods are:

• DiffUtils.diff(List> original, List> revised): Patch patch
• DiffUtils.patch(List> original, Patch patch): List> revised
• DiffUtils.unpatch(List> revised, Patch patch): List> original
• DiffUtils.parseUnifiedDiff(List diff): Patch patch
• DiffUtils.getDiffRows(List original, List revised): List diffRows

NOTE: All up-to-date examples can be found here.

Basic use in a Java App

Task 1: Compute the difference between to files and print its deltas

Solution:

import difflib.*;

public class BasicJavaApp_Task1 { // Helper method for get the file content private static List fileToLines(String filename) { List lines = new LinkedList(); String line = ""; try { BufferedReader in = new BufferedReader(new FileReader(filename)); while ((line = in.readLine()) != null) { lines.add(line); } } catch (IOException e) { e.printStackTrace(); } return lines; }

    public static void main(String[] args) {
            List<String> original = fileToLines("originalFile.txt");
            List<String> revised  = fileToLines("revisedFile.xt");
            
            // Compute diff. Get the Patch object. Patch is the container for computed deltas.
            Patch patch = DiffUtils.diff(original, revised);

            for (Delta delta: patch.getDeltas()) {
                    System.out.println(delta);
            }
    }

} Task 2: Get the file in unified format and apply it as the patch to given text Solution:

import difflib.*;

public class BasicJavaApp_Task2 { private List originalList = Arrays.asList("aaa", "bbb", "ccc");

    // Helper method for get the file content
    private List<String> fileToLines(String filename) {
            List<String> lines = new LinkedList<String>();
            String line = "";
            try {
                    BufferedReader in = new BufferedReader(new FileReader(filename));
                    while ((line = in.readLine()) != null) {
                            lines.add(line);
                    }
            } catch (IOException e) {
                    e.printStackTrace();
            }
            return lines;
    }

    public static void main(String[] args) {
            // At first, parse the unified diff file and get the patch
            Patch patch = DiffUtils.parseUnifiedDiff(fileToLines("example.diff"));
            
            // Then apply the computed patch to the given text
            List result = DiffUtils.patch(original, patch);
            /// Or we can call patch.applyTo(original). There is no difference.
    }

} Task 3: Compute the difference between to texts and print it in human-readable side-by-side view Solution:

Coming soon...