Class DiffFormatter

java.lang.Object
org.eclipse.jgit.diff.DiffFormatter
All Implemented Interfaces:
AutoCloseable
Direct Known Subclasses:
PatchIdDiffFormatter

public class DiffFormatter extends Object implements AutoCloseable
Format a Git style patch script.
  • Constructor Details

    • DiffFormatter

      public DiffFormatter(OutputStream out)
      Create a new formatter with a default level of context.
      Parameters:
      out - the stream the formatter will write line data to. This stream should have buffering arranged by the caller, as many small writes are performed to it.
  • Method Details

    • getOutputStream

      protected OutputStream getOutputStream()
      Get output stream
      Returns:
      the stream we are outputting data to
    • setRepository

      public void setRepository(Repository repository)
      Set the repository the formatter can load object contents from. Once a repository has been set, the formatter must be released to ensure the internal ObjectReader is able to release its resources.
      Parameters:
      repository - source repository holding referenced objects.
    • setReader

      public void setReader(ObjectReader reader, Config cfg)
      Set the repository the formatter can load object contents from.
      Parameters:
      reader - source reader holding referenced objects. Caller is responsible for closing the reader.
      cfg - config specifying diff algorithm and rename detection options.
      Since:
      4.5
    • setContext

      public void setContext(int lineCount)
      Change the number of lines of context to display.
      Parameters:
      lineCount - number of lines of context to see before the first modification and after the last modification within a hunk of the modified file.
    • setAbbreviationLength

      public void setAbbreviationLength(int count)
      Change the number of digits to show in an ObjectId.
      Parameters:
      count - number of digits to show in an ObjectId.
    • setDiffAlgorithm

      public void setDiffAlgorithm(DiffAlgorithm alg)
      Set the algorithm that constructs difference output.
      Parameters:
      alg - the algorithm to produce text file differences.
      See Also:
    • setDiffComparator

      public void setDiffComparator(RawTextComparator cmp)
      Set the line equivalence function for text file differences.
      Parameters:
      cmp - The equivalence function used to determine if two lines of text are identical. The function can be changed to ignore various types of whitespace.
      See Also:
    • setBinaryFileThreshold

      public void setBinaryFileThreshold(int threshold)
      Set maximum file size for text files. Files larger than this size will be treated as though they are binary and not text. Default is 52428800 .
      Parameters:
      threshold - the limit, in bytes. Files larger than this size will be assumed to be binary, even if they aren't.
    • setOldPrefix

      public void setOldPrefix(String prefix)
      Set the prefix applied in front of old file paths.
      Parameters:
      prefix - the prefix in front of old paths. Typically this is the standard string "a/", but may be any prefix desired by the caller. Must not be null. Use the empty string to have no prefix at all.
    • getOldPrefix

      public String getOldPrefix()
      Get the prefix applied in front of old file paths.
      Returns:
      the prefix
      Since:
      2.0
    • setNewPrefix

      public void setNewPrefix(String prefix)
      Set the prefix applied in front of new file paths.
      Parameters:
      prefix - the prefix in front of new paths. Typically this is the standard string "b/", but may be any prefix desired by the caller. Must not be null. Use the empty string to have no prefix at all.
    • getNewPrefix

      public String getNewPrefix()
      Get the prefix applied in front of new file paths.
      Returns:
      the prefix
      Since:
      2.0
    • isDetectRenames

      public boolean isDetectRenames()
      Get if rename detection is enabled
      Returns:
      true if rename detection is enabled
    • setDetectRenames

      public void setDetectRenames(boolean on)
      Enable or disable rename detection. Before enabling rename detection the repository must be set with setRepository(Repository). Once enabled the detector can be configured away from its defaults by obtaining the instance directly from getRenameDetector() and invoking configuration.
      Parameters:
      on - if rename detection should be enabled.
    • getRenameDetector

      public RenameDetector getRenameDetector()
      Get rename detector
      Returns:
      the rename detector if rename detection is enabled
    • setProgressMonitor

      public void setProgressMonitor(ProgressMonitor pm)
      Set the progress monitor for long running rename detection.
      Parameters:
      pm - progress monitor to receive rename detection status through.
    • setQuotePaths

      public void setQuotePaths(boolean quote)
      Sets whether or not path names should be quoted.

      By default the setting of git config core.quotePath is active, but this can be overridden through this method.

      Parameters:
      quote - whether to quote path names
      Since:
      5.6
    • setPathFilter

      public void setPathFilter(TreeFilter filter)
      Set the filter to produce only specific paths. If the filter is an instance of FollowFilter, the filter path will be updated during successive scan or format invocations. The updated path can be obtained from getPathFilter().
      Parameters:
      filter - the tree filter to apply.
    • getPathFilter

      public TreeFilter getPathFilter()
      Get path filter
      Returns:
      the current path filter
    • flush

      public void flush() throws IOException
      Flush the underlying output stream of this formatter.
      Throws:
      IOException - the stream's own flush method threw an exception.
    • close

      public void close()

      Release the internal ObjectReader state.

      Specified by:
      close in interface AutoCloseable
      Since:
      4.0
    • scan

      public List<DiffEntry> scan(AnyObjectId a, AnyObjectId b) throws IOException
      Determine the differences between two trees. No output is created, instead only the file paths that are different are returned. Callers may choose to format these paths themselves, or convert them into FileHeader instances with a complete edit list by calling toFileHeader(DiffEntry).

      Either side may be null to indicate that the tree has beed added or removed. The diff will be computed against nothing.

      Parameters:
      a - the old (or previous) side or null
      b - the new (or updated) side or null
      Returns:
      the paths that are different.
      Throws:
      IOException - trees cannot be read or file contents cannot be read.
    • scan

      public List<DiffEntry> scan(RevTree a, RevTree b) throws IOException
      Determine the differences between two trees. No output is created, instead only the file paths that are different are returned. Callers may choose to format these paths themselves, or convert them into FileHeader instances with a complete edit list by calling toFileHeader(DiffEntry).

      Either side may be null to indicate that the tree has beed added or removed. The diff will be computed against nothing.

      Parameters:
      a - the old (or previous) side or null
      b - the new (or updated) side or null
      Returns:
      the paths that are different.
      Throws:
      IOException - trees cannot be read or file contents cannot be read.
    • scan

      Determine the differences between two trees. No output is created, instead only the file paths that are different are returned. Callers may choose to format these paths themselves, or convert them into FileHeader instances with a complete edit list by calling toFileHeader(DiffEntry).
      Parameters:
      a - the old (or previous) side.
      b - the new (or updated) side.
      Returns:
      the paths that are different.
      Throws:
      IOException - trees cannot be read or file contents cannot be read.
    • format

      public void format(AnyObjectId a, AnyObjectId b) throws IOException
      Format the differences between two trees. The patch is expressed as instructions to modify a to make it b.

      Either side may be null to indicate that the tree has beed added or removed. The diff will be computed against nothing.

      Parameters:
      a - the old (or previous) side or null
      b - the new (or updated) side or null
      Throws:
      IOException - trees cannot be read, file contents cannot be read, or the patch cannot be output.
    • format

      public void format(RevTree a, RevTree b) throws IOException
      Format the differences between two trees. The patch is expressed as instructions to modify a to make it b.

      Either side may be null to indicate that the tree has beed added or removed. The diff will be computed against nothing.

      Parameters:
      a - the old (or previous) side or null
      b - the new (or updated) side or null
      Throws:
      IOException - trees cannot be read, file contents cannot be read, or the patch cannot be output.
    • format

      public void format(AbstractTreeIterator a, AbstractTreeIterator b) throws IOException
      Format the differences between two trees. The patch is expressed as instructions to modify a to make it b.

      Either side may be null to indicate that the tree has beed added or removed. The diff will be computed against nothing.

      Parameters:
      a - the old (or previous) side or null
      b - the new (or updated) side or null
      Throws:
      IOException - trees cannot be read, file contents cannot be read, or the patch cannot be output.
    • format

      public void format(List<? extends DiffEntry> entries) throws IOException
      Format a patch script from a list of difference entries. Requires scan(AbstractTreeIterator, AbstractTreeIterator) to have been called first.
      Parameters:
      entries - entries describing the affected files.
      Throws:
      IOException - a file's content cannot be read, or the output stream cannot be written to.
    • format

      public void format(DiffEntry ent) throws IOException
      Format a patch script for one file entry.
      Parameters:
      ent - the entry to be formatted.
      Throws:
      IOException - a file's content cannot be read, or the output stream cannot be written to.
    • format

      public void format(FileHeader head, RawText a, RawText b) throws IOException
      Format a patch script, reusing a previously parsed FileHeader.

      This formatter is primarily useful for editing an existing patch script to increase or reduce the number of lines of context within the script. All header lines are reused as-is from the supplied FileHeader.

      Parameters:
      head - existing file header containing the header lines to copy.
      a - text source for the pre-image version of the content. This must match the content of DiffEntry.getOldId().
      b - text source for the post-image version of the content. This must match the content of DiffEntry.getNewId().
      Throws:
      IOException - writing to the supplied stream failed.
    • format

      public void format(EditList edits, RawText a, RawText b) throws IOException
      Formats a list of edits in unified diff format
      Parameters:
      edits - some differences which have been calculated between A and B
      a - the text A which was compared
      b - the text B which was compared
      Throws:
      IOException - if an IO error occurred
    • writeContextLine

      protected void writeContextLine(RawText text, int line) throws IOException
      Output a line of context (unmodified line).
      Parameters:
      text - RawText for accessing raw data
      line - the line number within text
      Throws:
      IOException - if an IO error occurred
    • writeAddedLine

      protected void writeAddedLine(RawText text, int line) throws IOException
      Output an added line.
      Parameters:
      text - RawText for accessing raw data
      line - the line number within text
      Throws:
      IOException - if an IO error occurred
    • writeRemovedLine

      protected void writeRemovedLine(RawText text, int line) throws IOException
      Output a removed line
      Parameters:
      text - RawText for accessing raw data
      line - the line number within text
      Throws:
      IOException - if an IO error occurred
    • writeHunkHeader

      protected void writeHunkHeader(int aStartLine, int aEndLine, int bStartLine, int bEndLine) throws IOException
      Output a hunk header
      Parameters:
      aStartLine - within first source
      aEndLine - within first source
      bStartLine - within second source
      bEndLine - within second source
      Throws:
      IOException - if an IO error occurred
    • writeLine

      protected void writeLine(char prefix, RawText text, int cur) throws IOException
      Write a standard patch script line.
      Parameters:
      prefix - prefix before the line, typically '-', '+', ' '.
      text - the text object to obtain the line from.
      cur - line number to output.
      Throws:
      IOException - the stream threw an exception while writing to it.
    • toFileHeader

      Creates a FileHeader representing the given DiffEntry

      This method does not use the OutputStream associated with this DiffFormatter instance. It is therefore safe to instantiate this DiffFormatter instance with a DisabledOutputStream if this method is the only one that will be used.

      Parameters:
      ent - the DiffEntry to create the FileHeader for
      Returns:
      a FileHeader representing the DiffEntry. The FileHeader's buffer will contain only the header of the diff output. It will also contain one HunkHeader.
      Throws:
      IOException - the stream threw an exception while writing to it, or one of the blobs referenced by the DiffEntry could not be read.
      CorruptObjectException - one of the blobs referenced by the DiffEntry is corrupt.
      MissingObjectException - one of the blobs referenced by the DiffEntry is missing.
    • formatGitDiffFirstHeaderLine

      protected void formatGitDiffFirstHeaderLine(ByteArrayOutputStream o, DiffEntry.ChangeType type, String oldPath, String newPath) throws IOException
      Output the first header line
      Parameters:
      o - The stream the formatter will write the first header line to
      type - The DiffEntry.ChangeType
      oldPath - old path to the file
      newPath - new path to the file
      Throws:
      IOException - the stream threw an exception while writing to it.
    • formatIndexLine

      protected void formatIndexLine(OutputStream o, DiffEntry ent) throws IOException
      Format index line
      Parameters:
      o - the stream the formatter will write line data to
      ent - the DiffEntry to create the FileHeader for
      Throws:
      IOException - writing to the supplied stream failed.