Java tutorial
package org.apache.maven.scm.provider.git.jgit.command.checkout; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.apache.maven.scm.ScmException; import org.apache.maven.scm.ScmFile; import org.apache.maven.scm.ScmFileSet; import org.apache.maven.scm.ScmFileStatus; import org.apache.maven.scm.ScmTag; import org.apache.maven.scm.ScmVersion; import org.apache.maven.scm.command.checkout.AbstractCheckOutCommand; import org.apache.maven.scm.command.checkout.CheckOutScmResult; import org.apache.maven.scm.command.remoteinfo.RemoteInfoScmResult; import org.apache.maven.scm.provider.ScmProviderRepository; import org.apache.maven.scm.provider.git.command.GitCommand; import org.apache.maven.scm.provider.git.jgit.command.JGitUtils; import org.apache.maven.scm.provider.git.jgit.command.branch.JGitBranchCommand; import org.apache.maven.scm.provider.git.jgit.command.remoteinfo.JGitRemoteInfoCommand; import org.apache.maven.scm.provider.git.repository.GitScmProviderRepository; import org.codehaus.plexus.util.StringUtils; import org.eclipse.jgit.api.CloneCommand; import org.eclipse.jgit.api.Git; import org.eclipse.jgit.lib.Constants; import org.eclipse.jgit.lib.ProgressMonitor; import org.eclipse.jgit.revwalk.RevCommit; import org.eclipse.jgit.revwalk.RevWalk; import org.eclipse.jgit.storage.file.WindowCacheConfig; import org.eclipse.jgit.transport.CredentialsProvider; import org.eclipse.jgit.treewalk.TreeWalk; import java.io.File; import java.util.ArrayList; import java.util.List; import java.util.Set; /** * @author <a href="mailto:struberg@yahoo.de">Mark Struberg</a> * @author Dominik Bartholdi (imod) * @since 1.9 */ public class JGitCheckOutCommand extends AbstractCheckOutCommand implements GitCommand { /** * For git, the given repository is a remote one. We have to clone it first if the working directory does not * contain a git repo yet, otherwise we have to git-pull it. * <p/> * {@inheritDoc} */ protected CheckOutScmResult executeCheckOutCommand(ScmProviderRepository repo, ScmFileSet fileSet, ScmVersion version, boolean recursive) throws ScmException { GitScmProviderRepository repository = (GitScmProviderRepository) repo; if (GitScmProviderRepository.PROTOCOL_FILE.equals(repository.getFetchInfo().getProtocol()) && repository.getFetchInfo().getPath().indexOf(fileSet.getBasedir().getPath()) >= 0) { throw new ScmException("remote repository must not be the working directory"); } Git git = null; try { ProgressMonitor monitor = JGitUtils.getMonitor(getLogger()); String branch = version != null ? version.getName() : null; if (StringUtils.isBlank(branch)) { branch = Constants.MASTER; } getLogger().debug("try checkout of branch: " + branch); if (!fileSet.getBasedir().exists() || !(new File(fileSet.getBasedir(), ".git").exists())) { if (fileSet.getBasedir().exists()) { // git refuses to clone otherwise fileSet.getBasedir().delete(); } // FIXME only if windauze WindowCacheConfig cfg = new WindowCacheConfig(); cfg.setPackedGitMMAP(false); cfg.install(); // no git repo seems to exist, let's clone the original repo CredentialsProvider credentials = JGitUtils.getCredentials((GitScmProviderRepository) repo); getLogger().info("cloning [" + branch + "] to " + fileSet.getBasedir()); CloneCommand command = Git.cloneRepository().setURI(repository.getFetchUrl()); command.setCredentialsProvider(credentials).setBranch(branch).setDirectory(fileSet.getBasedir()); command.setProgressMonitor(monitor); git = command.call(); } JGitRemoteInfoCommand remoteInfoCommand = new JGitRemoteInfoCommand(); remoteInfoCommand.setLogger(getLogger()); RemoteInfoScmResult result = remoteInfoCommand.executeRemoteInfoCommand(repository, fileSet, null); if (git == null) { git = Git.open(fileSet.getBasedir()); } if (fileSet.getBasedir().exists() && new File(fileSet.getBasedir(), ".git").exists() && result.getBranches().size() > 0) { // git repo exists, so we must git-pull the changes CredentialsProvider credentials = JGitUtils.prepareSession(getLogger(), git, repository); if (version != null && StringUtils.isNotEmpty(version.getName()) && (version instanceof ScmTag)) { // A tag will not be pulled but we only fetch all the commits from the upstream repo // This is done because checking out a tag might not happen on the current branch // but create a 'detached HEAD'. // In fact, a tag in git may be in multiple branches. This occurs if // you create a branch after the tag has been created getLogger().debug("fetch..."); git.fetch().setCredentialsProvider(credentials).setProgressMonitor(monitor).call(); } else { getLogger().debug("pull..."); git.pull().setCredentialsProvider(credentials).setProgressMonitor(monitor).call(); } } Set<String> localBranchNames = JGitBranchCommand.getShortLocalBranchNames(git); if (version instanceof ScmTag) { getLogger().info("checkout tag [" + branch + "] at " + fileSet.getBasedir()); git.checkout().setName(branch).call(); } else if (localBranchNames.contains(branch)) { getLogger().info("checkout [" + branch + "] at " + fileSet.getBasedir()); git.checkout().setName(branch).call(); } else { getLogger().info("checkout remote branch [" + branch + "] at " + fileSet.getBasedir()); git.checkout().setName(branch).setCreateBranch(true) .setStartPoint(Constants.DEFAULT_REMOTE_NAME + "/" + branch).call(); } RevWalk revWalk = new RevWalk(git.getRepository()); RevCommit commit = revWalk.parseCommit(git.getRepository().resolve(Constants.HEAD)); revWalk.release(); final TreeWalk walk = new TreeWalk(git.getRepository()); walk.reset(); // drop the first empty tree, which we do not need here walk.setRecursive(true); walk.addTree(commit.getTree()); List<ScmFile> listedFiles = new ArrayList<ScmFile>(); while (walk.next()) { listedFiles.add(new ScmFile(walk.getPathString(), ScmFileStatus.CHECKED_OUT)); } walk.release(); getLogger().debug("current branch: " + git.getRepository().getBranch()); return new CheckOutScmResult("checkout via JGit", listedFiles); } catch (Exception e) { throw new ScmException("JGit checkout failure!", e); } finally { JGitUtils.closeRepo(git); } } }