Java tutorial
/* * ModeShape (http://www.modeshape.org) * * 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. */ package org.modeshape.connector.git; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.util.Collections; import java.util.List; import org.eclipse.jgit.api.Git; import org.eclipse.jgit.api.errors.GitAPIException; import org.eclipse.jgit.diff.DiffEntry; import org.eclipse.jgit.diff.DiffFormatter; import org.eclipse.jgit.errors.CorruptObjectException; import org.eclipse.jgit.errors.IncorrectObjectTypeException; import org.eclipse.jgit.errors.MissingObjectException; import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.Repository; import org.eclipse.jgit.revwalk.RevCommit; import org.eclipse.jgit.revwalk.RevWalk; import org.eclipse.jgit.treewalk.TreeWalk; import org.infinispan.schematic.document.Document; import org.modeshape.jcr.spi.federation.DocumentWriter; import org.modeshape.jcr.spi.federation.PageKey; import org.modeshape.jcr.spi.federation.PageWriter; /** * A {@link GitFunction} that returns the information about a particular commit. The structure of this area of the repository is * as follows: * * <pre> * /commit/{branchOrTagNameOrObjectId} * </pre> */ public class GitCommitDetails extends GitFunction implements PageableGitFunction { /** * The name of the character set that is used when building the patch difference for a commit. */ public static final String DIFF_CHARSET_NAME = "UTF-8"; protected static final String NAME = "commit"; protected static final String ID = "/commit"; protected static Object referenceToCommit(ObjectId id, Values values) { return values.referenceTo(ID + DELIMITER + id.getName()); } protected static Object[] referencesToCommits(ObjectId[] ids, Values values) { int size = ids.length; Object[] results = new Object[size]; for (int i = 0; i != size; ++i) { results[i] = referenceToCommit(ids[i], values); } return results; } public GitCommitDetails(GitConnector connector) { super(NAME, connector); } @Override public Document execute(Repository repository, Git git, CallSpecification spec, DocumentWriter writer, Values values) throws GitAPIException, IOException { if (spec.parameterCount() == 0) { // This is the top-level "/commit" node writer.setPrimaryType(GitLexicon.DETAILS); // Generate the child references to the branches, tags, and commits in the history ... addBranchesAsChildren(git, spec, writer); addTagsAsChildren(git, spec, writer); addCommitsAsChildren(git, spec, writer, pageSize); } else if (spec.parameterCount() == 1) { // This is the top-level "/commit/{branchOrTagNameOrObjectId}" node writer.setPrimaryType(GitLexicon.DETAILED_COMMIT); // Add the properties describing this commit ... RevWalk walker = new RevWalk(repository); walker.setRetainBody(true); try { String branchOrTagOrCommitId = spec.parameter(0); ObjectId objId = resolveBranchOrTagOrCommitId(repository, branchOrTagOrCommitId); RevCommit commit = walker.parseCommit(objId); writer.addProperty(GitLexicon.OBJECT_ID, objId.name()); writer.addProperty(GitLexicon.AUTHOR, authorName(commit)); writer.addProperty(GitLexicon.COMMITTER, commiterName(commit)); writer.addProperty(GitLexicon.COMMITTED, values.dateFrom(commit.getCommitTime())); writer.addProperty(GitLexicon.TITLE, commit.getShortMessage()); writer.addProperty(GitLexicon.MESSAGE, commit.getFullMessage().trim());// removes trailing whitespace writer.addProperty(GitLexicon.PARENTS, GitCommitDetails.referencesToCommits(commit.getParents(), values)); writer.addProperty(GitLexicon.TREE, GitTree.referenceToTree(objId, objId.name(), values)); // Compute the difference between the commit and it's parent(s), and generate the diff/patch file ... List<DiffEntry> differences = computeDifferences(commit, walker, repository); String patchFile = computePatch(differences, repository); writer.addProperty(GitLexicon.DIFF, patchFile); } finally { walker.dispose(); } } else { return null; } return writer.document(); } @Override public boolean isPaged() { return true; } @Override public Document execute(Repository repository, Git git, CallSpecification spec, PageWriter writer, Values values, PageKey pageKey) throws GitAPIException, IOException { if (spec.parameterCount() != 0) return null; addCommitsAsPageOfChildren(git, repository, spec, writer, pageKey); return writer.document(); } protected List<DiffEntry> computeDifferences(RevCommit commit, RevWalk walker, Repository repository) throws MissingObjectException, IncorrectObjectTypeException, CorruptObjectException, IOException { // Set up the tree walk to obtain the difference between the commit and it's parent(s) ... TreeWalk tw = new TreeWalk(repository); tw.setRecursive(true); tw.addTree(commit.getTree()); RevCommit[] parents = commit.getParents(); for (RevCommit parent : parents) { RevCommit parentCommit = walker.parseCommit(parent); tw.addTree(parentCommit.getTree()); //if there are multiple parents, we can't really have a multiple-way diff so we'll only look at the first parent if (parents.length > 1) { connector.getLogger().warn(GitI18n.commitWithMultipleParents, commit.getName(), parentCommit.getName()); break; } } if (tw.getTreeCount() == 1) { connector.getLogger().warn(GitI18n.commitWithSingleParent, commit.getName(), tw.getObjectId(0).name()); return Collections.emptyList(); } // Now process the diff of each file ... return DiffEntry.scan(tw); } protected String computePatch(Iterable<DiffEntry> entries, Repository repository) throws IOException { ByteArrayOutputStream output = new ByteArrayOutputStream(); DiffFormatter formatter = new DiffFormatter(output); formatter.setRepository(repository); for (DiffEntry entry : entries) { formatter.format(entry); } return output.toString(DIFF_CHARSET_NAME); } }