问题
Using JGit, I want to get a list of changes in files of a commits as is possible with git log --full-history -p -1 <hash-id>.
Is this possible? If so, how do you do it?
I know how to get each commit, and look at the commit message:
//Load repo
FileRepositoryBuilder builder = new FileRepositoryBuilder();
Repository repo = builder.setGitDir(new File("/path/to/repo/.git")).setMustExist(true).build();
Git git = new Git(repo);
//get commits
Iterable<RevCommit> log = git.log().call();
for (RevCommit commit : log) {
//Shows the hashid
System.out.println("LogCommit: " + commit);
//Shows only commit message
String logMessage = commit.getFullMessage();
System.out.println("LogMessage: " + logMessage);
}
git.close();
What allows me to get the changes in the files?
For example I write:
git log --full-history -p -1 8309c1262e1b7ffce8fc86efc1ae5777a4a96777
The response is
commit 8309c1262e1b7ffce8fc86efc1ae5777a4a96777
Author: <redacted>
Date: Thu Aug 4 12:15:23 2016 -0400
Fixed typo in commit
diff --git a/Product/Production/Common/CONNECTCoreLib/src/main/java/gov/hhs/fha/nhinc/messaging/server/BaseService.java b/Product/Production/Common/CONNECTCoreLib/src/main/java/gov/hhs/fha/nhinc/messaging/server/BaseService.java
index fa55e7e..4f3c155 100644
--- a/Product/Production/Common/CONNECTCoreLib/src/main/java/gov/hhs/fha/nhinc/messaging/server/BaseService.java
+++ b/Product/Production/Common/CONNECTCoreLib/src/main/java/gov/hhs/fha/nhinc/messaging/server/BaseService.java
@@ -56,6 +57,7 @@ public abstract class BaseService {
protected AssertionType getAssertion(WebServiceContext context, AssertionType assertionIn) {
AssertionType assertion;
- WSAHeaderHelper wsaHlpr = new WSAHeaderHelper();
+ WSAHeaderHelper wsaHelper = new WSAHeaderHelper();
if (assertionIn == null) {
assertion = SAML2AssertionExtractor.getInstance().extractSamlAssertion(context);
I want to have something like the following. Change is a made up class:
//Load repo
FileRepositoryBuilder builder = new FileRepositoryBuilder();
Repository repo = builder.setGitDir(new File("/path/to/repo/.git")).setMustExist(true).build();
Git git = new Git(repo);
//get commits
Iterable<RevCommit> log = git.log().call();
for (RevCommit commit : log) {
//Shows the hashid
System.out.println("LogCommit: " + commit);
//Shows only commit message
String logMessage = commit.getFullMessage();
System.out.println("LogMessage: " + logMessage);
List<Change> changes = commit.getChanges();
for(Change change: changes):
System.out.println("File: " + change.getFile());
System.out.println("Change: " + change.getChange());
System.out.println("ChangeType: " + change.getChangeType());
}
git.close();
The output would look something like:
LogCommit: 8309c1262e1b7ffce8fc86efc1ae5777a4a96777
LogMessage: Fixed typo in commit
File: Product/Production/Common/CONNECTCoreLib/src/main/java/gov/hhs/fha/nhinc/messaging/server/BaseService.java
Change: WSAHeaderHelper wsaHlpr = new WSAHeaderHelper();
ChangeType: D
File: Product/Production/Common/CONNECTCoreLib/src/main/java/gov/hhs/fha/nhinc/messaging/server/BaseService.java
Change: WSAHeaderHelper wsaHelper = new WSAHeaderHelper();
ChangeType: A
回答1:
JGit has a very simple diff command that writes a textual diff of the changes between two commits to an output stream.
For example:
OutputStream outputStream = ...
List<DiffEntry> diffEntries = git.diff().setOutputStream(outputStream).call();
Probably more interesting is the list of DiffEntry returned after calling the command.
Each DiffEntry represents a changed file and tells its path name, whether it was added, changed, or deleted, pointers (blob-ID's) to the old and new content and more.
And from each DiffEntry, you can obtain an EditList which holds information about which lines were changed.
For Example:
try (DiffFormatter diffFormatter = new DiffFormatter(DisabledOutputStream.INSTANCE)) {
diffFormatter.setRepository(git.getRepository());
List<DiffEntry> diffEntries = diffFormatter.scan(oldTreeIterator, newTreeIterator);
FileHeader fileHeader = diffFormatter.toFileHeader(diffEntries.get(0));
return fileHeader.toEditList();
}
This code also shows how to obtain diff entries with more detailed control without using the DiffCommand.
Just recently I wrote an entire blog post about JGit's diff APIs. For more details please see here: http://www.codeaffine.com/2016/06/16/jgit-diff/
回答2:
Thanks to Rüdiger Herrmann for the feedback and part of the code found on his gist.
I created a method diffCommit(String hashID), with 3 helper functions that will work exactly like git log --full-history -p -1 <hash-id>.
private Git git;
private Repository repo;
private void diffCommit(String hashID) throws IOException {
//Initialize repositories.
FileRepositoryBuilder builder = new FileRepositoryBuilder();
repo = builder.setGitDir(new File("/path/to/repo" + "/.git")).setMustExist(true)
.build();
git = new Git(repo);
//Get the commit you are looking for.
RevCommit newCommit;
try (RevWalk walk = new RevWalk(repo)) {
newCommit = walk.parseCommit(repo.resolve(hashID));
}
System.out.println("LogCommit: " + newCommit);
String logMessage = newCommit.getFullMessage();
System.out.println("LogMessage: " + logMessage);
//Print diff of the commit with the previous one.
System.out.println(getDiffOfCommit(newCommit));
}
//Helper gets the diff as a string.
private String getDiffOfCommit(RevCommit newCommit) throws IOException {
//Get commit that is previous to the current one.
RevCommit oldCommit = getPrevHash(newCommit);
if(oldCommit == null){
return "Start of repo";
}
//Use treeIterator to diff.
AbstractTreeIterator oldTreeIterator = getCanonicalTreeParser(oldCommit);
AbstractTreeIterator newTreeIterator = getCanonicalTreeParser(newCommit);
OutputStream outputStream = new ByteArrayOutputStream();
try (DiffFormatter formatter = new DiffFormatter(outputStream)) {
formatter.setRepository(git.getRepository());
formatter.format(oldTreeIterator, newTreeIterator);
}
String diff = outputStream.toString();
return diff;
}
//Helper function to get the previous commit.
public RevCommit getPrevHash(RevCommit commit) throws IOException {
try (RevWalk walk = new RevWalk(repo)) {
// Starting point
walk.markStart(commit);
int count = 0;
for (RevCommit rev : walk) {
// got the previous commit.
if (count == 1) {
return rev;
}
count++;
}
walk.dispose();
}
//Reached end and no previous commits.
return null;
}
//Helper function to get the tree of the changes in a commit. Written by Rüdiger Herrmann
private AbstractTreeIterator getCanonicalTreeParser(ObjectId commitId) throws IOException {
try (RevWalk walk = new RevWalk(git.getRepository())) {
RevCommit commit = walk.parseCommit(commitId);
ObjectId treeId = commit.getTree().getId();
try (ObjectReader reader = git.getRepository().newObjectReader()) {
return new CanonicalTreeParser(null, reader, treeId);
}
}
}
Here is additional code that will produce output similiar to git log --full-history
public void commit_logs() throws IOException, NoHeadException, GitAPIException {
List<String> logMessages = new ArrayList<String>();
FileRepositoryBuilder builder = new FileRepositoryBuilder();
Repository repo = builder.setGitDir(new File("/path/to/repo" + "/.git"))
.setMustExist(true).build();
git = new Git(repo);
Iterable<RevCommit> log = git.log().call();
RevCommit previousCommit = null;
for (RevCommit commit : log) {
if (previousCommit != null) {
AbstractTreeIterator oldTreeIterator = getCanonicalTreeParser( previousCommit );
AbstractTreeIterator newTreeIterator = getCanonicalTreeParser( commit );
OutputStream outputStream = new ByteArrayOutputStream();
try( DiffFormatter formatter = new DiffFormatter( outputStream ) ) {
formatter.setRepository( git.getRepository() );
formatter.format( oldTreeIterator, newTreeIterator );
}
String diff = outputStream.toString();
System.out.println(diff);
}
System.out.println("LogCommit: " + commit);
String logMessage = commit.getFullMessage();
System.out.println("LogMessage: " + logMessage);
logMessages.add(logMessage.trim());
previousCommit = commit;
}
git.close();
}
private AbstractTreeIterator getCanonicalTreeParser( ObjectId commitId ) throws IOException {
try( RevWalk walk = new RevWalk( git.getRepository() ) ) {
RevCommit commit = walk.parseCommit( commitId );
ObjectId treeId = commit.getTree().getId();
try( ObjectReader reader = git.getRepository().newObjectReader() ) {
return new CanonicalTreeParser( null, reader, treeId );
}
}
}
来源：https://stackoverflow.com/questions/39935160/how-to-use-jgit-to-get-list-of-changes-in-files