OpenRepository.java

package org.dstadler.jgit;

/*
   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 org.apache.commons.io.FileUtils;
import org.dstadler.jgit.helper.CookbookHelper;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.storage.file.FileRepositoryBuilder;

import java.io.File;
import java.io.IOException;

/**
 * Simple snippet which shows how to open an existing repository
 *
 * @author dominik.stadler at gmx.at
 */
public class OpenRepository {

    public static void main(String[] args) throws IOException, GitAPIException {
        // first create a test-repository, the return is including the .get directory here!
        File repoDir = createSampleGitRepo();

        // now open the resulting repository with a FileRepositoryBuilder
        FileRepositoryBuilder builder = new FileRepositoryBuilder();
        try (Repository repository = builder.setGitDir(repoDir)
                .readEnvironment() // scan environment GIT_* variables
                .findGitDir() // scan up the file system tree
                .build()) {
            System.out.println("Having repository: " + repository.getDirectory());

            // the Ref holds an ObjectId for any type of object (tree, commit, blob, tree)
            Ref head = repository.exactRef("refs/heads/master");
            System.out.println("Ref of refs/heads/master: " + head);
        }

        // clean up here to not keep using more and more disk-space for these samples
        FileUtils.deleteDirectory(repoDir.getParentFile());
    }

    private static File createSampleGitRepo() throws IOException, GitAPIException {
        try (Repository repository = CookbookHelper.createNewRepository()) {
            System.out.println("Temporary repository at " + repository.getDirectory());

            // create the file
            File myFile = new File(repository.getDirectory().getParent(), "testfile");
            if(!myFile.createNewFile()) {
                throw new IOException("Could not create file " + myFile);
            }

            // run the add-call
            try (Git git = new Git(repository)) {
                git.add()
                        .addFilepattern("testfile")
                        .call();


                // and then commit the changes
                git.commit()
                        .setMessage("Added testfile")
                        .call();
            }

            System.out.println("Added file " + myFile + " to repository at " + repository.getDirectory());

            return repository.getDirectory();
        }
    }
}