Workaround for github-api issue (https://github.com/github-api/github-api/issues/504)

GHApiTest.java

package org.beryx.test;

import org.kohsuke.github.*;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

public class GHApiTest {
    private static String REPO_NAME = "sandboxx/GHTreeBuilderTest";
    private static String GITHUB_OAUTH = System.getenv("GITHUB_OAUTH");

    public static GHTreeBuilder add(GHTreeBuilder builder, GHRepository repo, String path, String content, boolean executable) {
        return add(builder, repo, path, content.getBytes(StandardCharsets.UTF_8), executable);
    }

    public static GHTreeBuilder add(GHTreeBuilder builder, GHRepository repo, String path, byte[] content, boolean executable) {
        try {
            String dataSha = repo.createBlob()
                    .binaryContent(content)
                    .create()
                    .getSha();
            return builder.shaEntry(path, dataSha, executable);
        } catch (IOException e) {
            throw new GHException("Cannot create binary content of '" + path + "'", e);
        }
    }

    public static void main(String[] args) throws Exception {
        GitHub gitHub = GitHub.connectUsingOAuth(GITHUB_OAUTH);
        GHRepository repo = gitHub.getRepository(REPO_NAME);

        GHRef masterRef = repo.getRef("heads/master");
        String masterTreeSha = repo
                .getTreeRecursive("master", 1)
                .getSha();

        GHTreeBuilder treeBuilder = repo.createTree().baseTree(masterTreeSha);
        add(treeBuilder, repo, "app/run.sh", "#!/bin/bash\necho Hello\n", true);
        add(treeBuilder, repo, "doc/readme.txt", "Thanks for using our application!\n", false);
        add(treeBuilder, repo, "data/val1.dat", new byte[] {0x01, 0x02, 0x03}, false);

        String treeSha = treeBuilder.create().getSha();
        String commitSha = repo.createCommit()
                .message("Add content")
                .tree(treeSha)
                .parent(masterRef.getObject().getSha())
                .create()
                .getSHA1();
        masterRef.updateTo(commitSha);
    }
}