下面是一个使用Apache Commons Compress库的代码示例：

import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.ArchiveOutputStream;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
import org.apache.commons.compress.compressors.CompressorInputStream;
import org.apache.commons.compress.compressors.CompressorOutputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
import org.apache.commons.compress.utils.IOUtils;

import java.io.*;

public class ApacheCommonsCompressExample {

    public static void main(String[] args) throws IOException {
        // 创建一个压缩包
        createArchive("folder", "archive.tar.gz");

        // 解压缩包
        extractArchive("archive.tar.gz", "output");
    }

    public static void createArchive(String folderPath, String archivePath) throws IOException {
        File folder = new File(folderPath);
        File archiveFile = new File(archivePath);

        try (OutputStream fos = new FileOutputStream(archiveFile);
             CompressorOutputStream cos = new GzipCompressorOutputStream(fos);
             ArchiveOutputStream aos = new TarArchiveOutputStream(cos)) {

            // 遍历文件夹中的所有文件，并添加到压缩包中
            for (File file : folder.listFiles()) {
                ArchiveEntry entry = aos.createArchiveEntry(file, file.getName());
                aos.putArchiveEntry(entry);
                IOUtils.copy(new FileInputStream(file), aos);
                aos.closeArchiveEntry();
            }

            aos.finish();
        }
    }

    public static void extractArchive(String archivePath, String outputPath) throws IOException {
        File archiveFile = new File(archivePath);
        File outputFolder = new File(outputPath);

        try (InputStream fis = new FileInputStream(archiveFile);
             CompressorInputStream cis = new GzipCompressorInputStream(fis);
             ArchiveInputStream ais = new TarArchiveInputStream(cis)) {

            ArchiveEntry entry;
            while ((entry = ais.getNextEntry()) != null) {
                if (!ais.canReadEntryData(entry)) {
                    continue;
                }

                File outputFile = new File(outputFolder, entry.getName());

                if (entry.isDirectory()) {
                    if (!outputFile.exists()) {
                        outputFile.mkdirs();
                    }
                } else {
                    outputFile.getParentFile().mkdirs();
                    try (OutputStream fos = new FileOutputStream(outputFile)) {
                        IOUtils.copy(ais, fos);
                    }
                }
            }
        }
    }
}

上述代码展示了如何使用Apache Commons Compress库创建和解压缩.tar.gz文件。createArchive方法将指定文件夹中的所有文件添加到.tar.gz压缩包中，而extractArchive方法将.tar.gz文件解压缩到指定的输出文件夹中。

请注意，上述代码仅提供了基本示例，你可以根据自己的需求进行修改和扩展。确保你已经将Apache Commons Compress库添加到项目的依赖中。