iterating over all directories in a zip file java

Question

I'm currently developing a tool that would allow me to modify the md5 of a zip file. The directory structure of the file looks like

          baselines->
models -> icons    ->
          lang     ->
          (a bunch of files here)

However, when I run my code, none of those directories are getting iterating into. The output gives me:

Name:model/visualization_dependency.xml
Name:model/visualization_template.xml
Name:model/weldmgmt_dependency.xml
Name:model/weldmgmt_template.xml

I was expecting to something like model/baseline/somefile.xml appears on the output, but it does not. Any Thoughts?

byte[] digest = null;
        MessageDigest md5;

        try {
            md5 = MessageDigest.getInstance("MD5");

            ZipEntry current;
            while((current = entry.getNextEntry()) != null){

                //ZipEntry current = entry.getNextEntry();
                System.out.println("Size:" + current.getSize());
                System.out.println("Name:" + current.getName());

                if(current.isDirectory()){
                    digest = this.encodeUTF8(current.getName());
                    md5.update(digest);
                }
                else{
                    int size = (int)current.getSize();
                    digest = new byte[size];
                    entry.read(digest, 0, size);
                    md5.update(digest);
                }
            }
            digest = md5.digest();
            entry.close();
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

Answer 1

Once you check that existing folder is directory then you need to iterative go through each files in the directory and process each on of those.

Example:

if(current.isDirectory()){
  System.out.println("Directory: " + file.getName());
  //Get list of files by file.listFiles() and pass it to 
 // to other method that will do processing. 
  digest = this.encodeUTF8(current.getName());
  md5.update(digest);
}

---

Checkout this question, it details process well. Iterating inside directories in Java

Answer 2

I think your code is perfect. I suspect your zip file does not contain directories. They don't have to!

For example, here's a zip file I created with "a/b/c/d.txt". When I initially created it the directories were added to the zip file:

$ unzip -l a.zip 
Archive:  a.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  2012-06-12 14:22   a/
        0  2012-06-12 14:22   a/b/
        0  2012-06-12 14:22   a/b/c/
       19  2012-06-12 14:22   a/b/c/d.txt
---------                     -------
       19                     4 files

But then I deleted the directories from the zip index:

$ zip -d a.zip  a/b/c
deleting: a/b/c/
$ zip -d a.zip  a/b
deleting: a/b/
$ zip -d a.zip  a
deleting: a/

And now when I listed its contents, sure enough, only the file appears. The directories are gone:

$ unzip -l a.zip 
Archive:  a.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
       19  2012-06-12 14:22   a/b/c/d.txt
---------                     -------
       19                     1 file

Note: when I unzipped this same file, it created the a/b/c/ directory before extracting the d.txt file, even though the zip index itself contained no directories. So it looks like directory entries in zip files are completely optional.