java-diff-utils usage example

gistfile1.java

public class DiffTest {
    @Test
    public void parseDiffToSideBySideView() throws IOException {
        List<String> lines = IOUtils.readLines(FileUtils.openInputStream(new File("httpd.conf.diff")));

        Patch diff = DiffUtils.parseUnifiedDiff(lines);

        DiffRowGenerator.Builder builder = new DiffRowGenerator.Builder();
        builder.showInlineDiffs(false);
        DiffRowGenerator generator = builder.build();

        SideBySideView view = new SideBySideView();

        for (Delta delta : diff.getDeltas()) {
            List<DiffRow> generateDiffRows = generator.generateDiffRows(
                    (List<String>) delta.getOriginal().getLines(),
                    (List<String>) delta.getRevised().getLines()
                    );

            int leftPos = delta.getOriginal().getPosition();
            int rightPos = delta.getRevised().getPosition();

            for (DiffRow row : generateDiffRows) {
                SideBySideView.Line line = new SideBySideView.Line();

                Tag tag = row.getTag();
                if (tag == Tag.INSERT) {
                    line.left.cssClass = "old";

                    line.right.number = rightPos;
                    line.right.text = row.getNewLine();
                    line.right.cssClass = "new";
                    rightPos++;

                } else if (tag == Tag.CHANGE) {
                    line.left.number = leftPos;
                    line.left.text = row.getOldLine();
                    line.right.cssClass = "old";
                    leftPos++;

                    line.right.number = rightPos;
                    line.right.text = row.getNewLine();
                    line.right.cssClass = "new";
                    rightPos++;

                } else if (tag == Tag.DELETE) {
                    line.left.number = leftPos;
                    line.left.text = row.getOldLine();
                    line.left.cssClass = "old";
                    leftPos++;

                    line.right.cssClass = "new";

                } else if (tag == Tag.EQUAL) {
                    line.left.number = leftPos;
                    line.left.text = row.getOldLine();
                    leftPos++;

                    line.right.number = rightPos;
                    line.right.text = row.getNewLine();
                    rightPos++;

                } else {
                    throw new IllegalStateException("Unknown pattern tag: " + tag);
                }

                view.addLine(line);
            }
        }

        for (SideBySideView.Line line : view.lines) {
            System.out.printf("<left class=\"%s\"><num>%s</num><text>%s</text></left>" +
            		"<right class=\"%s\"><num>%s</num><text>%s</text></right>\n",
                    line.left.cssClass,
                    line.left.getNumber(),
                    line.left.text,
                    line.right.cssClass,
                    line.right.getNumber(),
                    line.right.text);
        }
    }

    public static class SideBySideView {
        private List<Line> lines = new ArrayList<Line>();

        public void addLine(Line line) {
            lines.add(line);
        }

        public static class Line {
            private Item left = new Item();
            private Item right = new Item();

            public static class Item {
                private Integer number;
                private String text = "";
                private String cssClass = "";

                public String getNumber() {
                    return (number == null) ? "" : String.valueOf(number);
                }
            }
        }
    }
}

Where is the file httpd.conf.diff located?