Android: Get Number of Files within Zip?

Question

I have a question that seems easy but I cannot seem to get it to work properly.

I have a zip file within my 'assets' folder that I need to unzip and I have a ProgessBar in which I want to display to the user how the progress is going.

I have everything working but I want to set the ProgessBar max value to be the number of files within the zip file. The number of files within this folder will sometimes change so I want the ProgessBar to be relative to how many files are contained within the zip.

I'm using the ZipInputStream-API but does not seem there is a way to get the number of files within the zip file. The only way I can of think of is doing this:

   ZipInputStream zin = new ZipInputStream(getAssets().open(
                                "myFile.zip"));
   int numFiles = 0;
   int increment = 0;
   while (zin.getNextEntry() != null) {
     numFiles++;
    }

    ZipEntry ze = null;
    //Set the Max..value here..
    progessBar.setMax(numFiles);                
    while ((ze = zin.getNextEntry()) != null) {
       increment++;
       progessBar.setProgress(increment);
    }

This works but having two while loops seems a bit redundant which are basically doing the same thing.

I know that there is a ZipFile-API which has a size()-method, but it requires a path to the file and since my file is located within the 'assets' folder I am pretty sure the only way to read from this directory is by streaming.

Is there a way for me to accomplish this?

Answer 1

Use ZipFile API, There is a size method that returns the number of ZipEntries in the ZipFile. You can read from assets folder.

example:

int zipEntriesCount(String path) throws IOException {

     ZipFile zf= new ZipFile(path);
     return zf.size();
}

Answer 2

Thanks for the answers. What I ended up doing using the: AssetFileDescriptor API to get the file size of the zip file and setting that as the ProgessBar.setMax() value. Then as I loop through the zip contents I increment the progress by using each entries file size. This works but the only concern I have is that the AssetFileDescriptor.getLength() value as well as the ZipEntry.getSize() values return a long value so I am forced to cast them to an integer before I can set the max and/or increment the ProgessBar so there is a slight possibility I might overload an integer value causing an exception but this is not likely because I do not anticipate my file sizes ever getting bigger than the max holding capacity of an integer.

ZipInputStream zin = new ZipInputStream(getAssets().open(
                            "myFile.zip"));
ZipEntry ze = null;
AssetFileDescriptor mydisc = getAssets().openFd("myFile.zip");
//Size of the zip package
long size = mydisc.getLength();
long increment = 0;
dialog.setMax((int) size);
while ((ze = zin.getNextEntry()) != null) {
     increment += (int) ze.getSize();
     progessBar.setProgess((int)increment);
     //do more stuff..
}

Not the best solution but it works.

I'm aware of the ZipFile API but it requires a string to be passed in but I am not sure what the path is to that directory or how to get it?