Question

I am having a problem with the compress apache library. I would like to untar an archive that contains binary files. Here is the code:

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;

public class ArchiveManager {

    public static final int BUFFER_MAX = 2048;

    public static void untar(String fileName, String targetPath) throws IOException {
        File tarArchiveFile = new File(fileName);
        BufferedOutputStream dest = null;
        FileInputStream tarArchiveStream = new FileInputStream(tarArchiveFile);
        TarArchiveInputStream tis = new TarArchiveInputStream(new BufferedInputStream(tarArchiveStream));
        TarArchiveEntry entry = null;
        try {
            while ((entry = tis.getNextTarEntry()) != null) {
                int count;
                File outputFile = new File(targetPath, entry.getName());

                if (entry.isDirectory()) { // entry is a directory
                    if (!outputFile.exists()) {
                        outputFile.mkdirs();
                    }
                } else { // entry is a file
                    byte[] data = new byte[BUFFER_MAX];
                    FileOutputStream fos = new FileOutputStream(outputFile);
                    dest = new BufferedOutputStream(fos, BUFFER_MAX);
                    while ((count = tis.read(data, 0, BUFFER_MAX)) != -1) {
                        dest.write(data, 0, count);
                    }
                    dest.flush();
                    dest.close();
                }
            }
        } catch(Exception e) {
            e.printStackTrace();
        } finally {
            if (dest != null) {
                dest.flush();
                dest.close();
            }
            tis.close();
        }
    }
}

When untaring binary files, getNextTarEntry() throws an exception:

java.lang.IllegalArgumentException: Invalid byte 111 at offset 0 in 'o.txt{NUL}{NUL}{NUL}' len=8
    at org.apache.commons.compress.archivers.tar.TarUtils.parseOctal(TarUtils.java:99)
    at org.apache.commons.compress.archivers.tar.TarArchiveEntry.parseTarHeader(TarArchiveEntry.java:786)
    at org.apache.commons.compress.archivers.tar.TarArchiveEntry.<init>(TarArchiveEntry.java:308)
    at org.apache.commons.compress.archivers.tar.TarArchiveInputStream.getNextTarEntry(TarArchiveInputStream.java:198)
    at com.airbus.pakito.download.ArchiveManager.untar(ArchiveManager.java:22)

I tried to untar simple text files. After having untared the last file, getNextTarEntry() does not return null but an object with empty fileds. So entry.getName() is empty and obviously new FileOutputStream(outputFile) cannot create a file.

java.io.FileNotFoundException: C:\Temp (Accès refusé)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(Unknown Source)
    at java.io.FileOutputStream.<init>(Unknown Source)
    at com.airbus.pakito.util.Archive.untar(Archive.java:32)

Do you have an idea where the problem comes from?

Thanks.

Answer 1

I finally found out where the problem comes from.

This is a known bug which is fixed in the 1.4 release of Apache compress. I hope this release will be available very soon.