Question

I am trying to unzip an archive (test.zip) containing a subfolder with some png images:

test.zip
  | -> images
         | -> a.png
         | -> b.png

Here is what I do:

  public static void unzip(String archive, File baseFolder, String[] ignoreExtensions) {
    FileInputStream fin;
    try {
      fin = new FileInputStream(archive);
      ZipInputStream zin = new ZipInputStream(fin);
      ZipEntry ze = null;
      while ((ze = zin.getNextEntry()) != null) {
        if (ignoreExtensions == null || !ignoreEntry(ze, ignoreExtensions)) {
          File destinationFile = new File(baseFolder, ze.getName());
          unpackEntry(destinationFile, zin);
        }
      }
      zin.close();
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  private static void unpackEntry(File destinationFile, ZipInputStream zin) {
    createParentFolder(destinationFile);
    FileOutputStream fout = null;
    try {
      fout = new FileOutputStream(destinationFile);
      for (int c = zin.read(); c != -1; c = zin.read()) {
        fout.write(c);
        zin.closeEntry();
        fout.close();
      }
    } catch (IOException e) {
      e.printStackTrace();
    }

  }

  private static void createParentFolder(File destinationFile) {
    File parent = new File(destinationFile.getParent());
    parent.mkdirs();
  }

The images are extracted to the correct location but are corrupt (the size is smaller than expected so I assume they are not decompressed).

If I open the test.zip file with 7Zip it works fine. Any ideas on how to unzip an archive with subfolders?

Answer 1

What are you doing here?

  for (int c = zin.read(); c != -1; c = zin.read()) {
    fout.write(c);
    zin.closeEntry();
    fout.close();
  }

Could it be that you meant this instead?

  for (int c = zin.read(); c != -1; c = zin.read()) {
    fout.write(c);
  }
  zin.closeEntry();
  fout.close();