如何使用 Apache Commons Compress 将文件附加到 .tar 存档？

Question

我阅读了How do I append files to a tar archive in java?、append files to an archive without reading/rewriting the whole archive 和Add an entry to a tar file without overwriting its existing contents，但没有给出好的答案。此外，我没有足够的声誉来发布 cmets。所以我在这里创建了一个新问题。

有没有办法在 tar 存档中附加文件？如果文件已经存在，我想替换它。

我已经开始编写以下方法，但是当添加文件时，它会删除存档内容。我在apache compress website 上没有找到任何示例。

    static final Logger LOG = Logger.getLogger(ShellClient.class);

public void appendFileInTarArchive(String tarPath, String tarFileName, String file2WriteName, String file2WriteContent) throws IOException {
    if (tarPath == null || tarFileName == null || tarFileName.isEmpty()) {
        LOG.warn("The path or the name of the tar archive is null or empty.");
        return;
    }
    final File tarFile = new File(tarPath, tarFileName);
    final File fileToAdd = new File(tarPath, file2WriteName);
    FileUtils.write(fileToAdd, file2WriteContent);

    if (file2WriteName == null || file2WriteName.isEmpty()) {
        LOG.warn("The name of the file to append in the archive is null or empty.");
        return;
    }

    TarArchiveOutputStream aos = null;
    OutputStream out = null;

    try {
        out = new FileOutputStream(tarFile);

        aos = (TarArchiveOutputStream) new ArchiveStreamFactory().createArchiveOutputStream(ArchiveStreamFactory.TAR, out);

        // create a new entry
        final TarArchiveEntry entry = new TarArchiveEntry(fileToAdd);
        entry.setSize(fileToAdd.length());

        // add the entry to the archive
        aos.putArchiveEntry(entry);
        InputStream is = new FileInputStream(fileToAdd);
        final int byteCopied = IOUtils.copy(is, aos);
        if (LOG.isDebugEnabled()) {
            LOG.debug(byteCopied+" bytes inserted in the tar archive from "+fileToAdd);
        }
        is.close();
        aos.closeArchiveEntry();
        aos.finish();
        aos.flush();
        aos.close();
        out.flush();
        out.close();

    } catch (ArchiveException e) {
        LOG.error(e.getMessage(), e);
    } catch (IOException e) {
        LOG.error(e.getMessage(), e);
    } finally {
        IOUtils.closeQuietly(aos);
        IOUtils.closeQuietly(out);
        FileUtils.deleteQuietly(fileToAdd);
    }
}

Answer 1

最后我使用this post成功做到了。

我创建了 tar 存档的副本并将整个内容复制到其中。然后我删除旧的 tar 存档。

public void appendFileInTarArchive(String tarPath, String tarFileName, String file2WriteName, String file2WriteContent) throws AuthenticationException, IOException {
    if (tarPath == null || tarFileName == null || tarFileName.isEmpty()) {
        LOG.warn("The path or the name of the tar archive is null or empty.");
        return;
    }
    final File tarFile = new File(tarPath, tarFileName);
    final File fileToAdd = new File(tarPath, file2WriteName);
    FileUtils.write(fileToAdd, file2WriteContent);

    if (file2WriteName == null || file2WriteName.isEmpty()) {
        LOG.warn("The name of the file to append in the archive is null or empty.");
        return;
    }

    ArchiveStreamFactory asf = new ArchiveStreamFactory();

    File tempFile = new File(tarPath, "tmpTar.tar");
    tempFile.createNewFile();

    try {
        FileInputStream fis = new FileInputStream(tarFile);
        ArchiveInputStream ais = asf.createArchiveInputStream(ArchiveStreamFactory.TAR, fis);

        FileOutputStream fos = new FileOutputStream(tempFile);
        ArchiveOutputStream aos = asf.createArchiveOutputStream(ArchiveStreamFactory.TAR, fos);

        // copy the existing entries    
        ArchiveEntry nextEntry;
        while ((nextEntry = ais.getNextEntry()) != null) {
            aos.putArchiveEntry(nextEntry);
            IOUtils.copy(ais, aos);
            aos.closeArchiveEntry();
        }

        // create the new entry
        TarArchiveEntry entry = new TarArchiveEntry(file2WriteName);
        entry.setSize(fileToAdd.length());
        aos.putArchiveEntry(entry);
        IOUtils.copy(new FileInputStream(fileToAdd), aos);
        aos.closeArchiveEntry();

        aos.finish();

        ais.close();
        aos.close();

        // copies the new file over the old
        tarFile.delete();
        tempFile.renameTo(tarFile);

    } catch (ArchiveException e) {
        LOG.error(e.getMessage(), e);
    } catch (IOException e) {
        LOG.error(e.getMessage(), e);
    } finally {
        FileUtils.deleteQuietly(fileToAdd);
    }
}