Package org.machanism.machai.gw.tools

Class PatchApplier

java.lang.Object

org.machanism.machai.gw.tools.PatchApplier

public class PatchApplier
extends Object

Utility to apply unified diff patches to text files.

Since:

1.2.0

Author:

Viktor Tovstyi

Constructor Summary

Constructors

Constructor	Description
PatchApplier()

Method Summary

Modifier and Type	Method	Description
static void	applyPatch(File file, List<String> patchLines, Charset charset)	Applies a unified or simplified diff patch to a file.
private static int	findHunkStart(List<String> fileLines, List<String> hunkLines, int expectedStart)
private static int	indexOfLine(List<String> lines, String expectedLine, int startIndex)
private static boolean	matchLines(List<String> fileLines, List<String> expectedLines, int startOffset)
private static void	validatePatchResult(List<String> original, List<String> modified, String fileName)	Asserts structural sanity on the patched code structure before writing to disk.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PatchApplier

public PatchApplier()

Method Details

applyPatch

public static void applyPatch(File file,
 List<String> patchLines,
 Charset charset)
                       throws IOException

Applies a unified or simplified diff patch to a file. Supports both standard unified diff headers (e.g. "@@ -1,5 +1,6 @@") and simplified search-and-replace headers (e.g. "@@").

Parameters:

file - The target file to patch.

patchLines - List of lines from the patch file.

charset - Charset for reading/writing the file.

Throws:

IOException - if file operations fail or patch cannot be applied.

validatePatchResult

private static void validatePatchResult(List<String> original,
 List<String> modified,
 String fileName)
                                 throws IOException

Asserts structural sanity on the patched code structure before writing to disk.

Throws:

IOException

findHunkStart

private static int findHunkStart(List<String> fileLines,
 List<String> hunkLines,
 int expectedStart)

matchLines

private static boolean matchLines(List<String> fileLines,
 List<String> expectedLines,
 int startOffset)

indexOfLine

private static int indexOfLine(List<String> lines,
 String expectedLine,
 int startIndex)