Add snippet for rebasing

README.md

@@ -71,6 +71,7 @@ This project tries to provide a collection of ready-to-run snippets which try to
 * [List remote heads/tags without a local clone](https://github.com/centic9/jgit-cookbook/blob/master/src/main/java/org/dstadler/jgit/porcelain/ListRemoteRepository.java)
 * [Fetch from remote repositories](https://github.com/centic9/jgit-cookbook/blob/master/src/main/java/org/dstadler/jgit/porcelain/FetchRemoteCommits.java)
 * [Clone a remote reppository via SSH protocol and username/password credentials](https://github.com/centic9/jgit-cookbook/blob/master/src/main/java/org/dstadler/jgit/porcelain/CloneRemoteRepositoryWithAuthentication.java)
+* [Rebase onto an upstream branch](https://github.com/centic9/jgit-cookbook/blob/master/src/main/java/org/dstadler/jgit/porcelain/RebaseToOriginMaster.java)
 
 ##### Low-level API
 
@@ -101,7 +102,6 @@ This project tries to provide a collection of ready-to-run snippets which try to
 * Git repo on Amazon S3: http://stackoverflow.com/questions/8744611/git-repository-on-s3-as-origin-not-as-backup http://stackoverflow.com/questions/7031729/publish-to-s3-using-git http://www.fancybeans.com/blog/2012/08/24/how-to-use-s3-as-a-private-git-repository/
 * Doing stuff without local storage: Using org.eclipse.jgit.storage.dfs.InMemoryRepository to clone a Git repo in-memory and work from there
 * CherryPick
-* Rebase - http://stackoverflow.com/questions/22945257/jgit-how-to-squash-commits
 * Submodules - http://www.codeaffine.com/2014/04/16/how-to-manage-git-submodules-with-jgit/
 
 #### Sources

src/main/java/org/dstadler/jgit/porcelain/RebaseToOriginMaster.java

@@ -0,0 +1,67 @@
+package org.dstadler.jgit.porcelain;
+
+/*
+   Copyright 2013, 2014 Dominik Stadler
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+ */
+
+import java.io.IOException;
+import java.util.List;
+
+import org.dstadler.jgit.helper.CookbookHelper;
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.RebaseCommand.InteractiveHandler;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.errors.IllegalTodoFileModification;
+import org.eclipse.jgit.lib.RebaseTodoLine;
+import org.eclipse.jgit.lib.RebaseTodoLine.Action;
+import org.eclipse.jgit.lib.Repository;
+
+/**
+ * Snippet which shows how to rebase local changes onto a remote branch.
+ *
+ * See also http://stackoverflow.com/questions/22945257/jgit-how-to-squash-commits
+ *
+ * @author dominik.stadler at gmx.at
+ */
+public class RebaseToOriginMaster {
+
+    public static void main(String[] args) throws IOException, GitAPIException {
+        try (Repository repository = CookbookHelper.openJGitCookbookRepository()) {
+            // all refs
+            try (Git git = new Git(repository)) {
+                InteractiveHandler handler = new InteractiveHandler() {
+                    @Override
+                    public void prepareSteps(List<RebaseTodoLine> steps) {
+                        for(RebaseTodoLine step : steps) {
+                            try {
+                                step.setAction(Action.EDIT);
+                            } catch (IllegalTodoFileModification e) {
+                                throw new IllegalStateException(e);
+                            }
+                        }
+                    }
+
+                    @Override
+                    public String modifyCommitMessage(String oldMessage) {
+                        return oldMessage;
+                    }
+                };
+
+                git.rebase().setUpstream("origin/master").runInteractively(handler).call();
+                System.out.println("Rebased..");
+            }
+        }
+    }
+}