Create 0% compressed zip file mac for expansion pack

Question

I am trying to create an expansion pack for an Android app which includes about 100 .mp3 files. As I understand from the documentation and this SO question, the zip file must be 0% compressed.

How do I create a 0% compressed zip file on a mac?

Answer 1

The following is a working implementation of the expansion pack with a zip file containing .mp3 files:

Create a zip file with 0% compression (on a mac in terminal):

1. Put all of the files you want to compress in a folder. Let's call it FOLDER_WITH_FILES_TO_ZIP

2. cd into the parent directory of FOLDER_WITH_FILES_TO_ZIP

3. Use the following bash script to create a zip file with file name FILENAME.zip

   $ zip -0 -r FILENAME.zip FOLDER_WITH_FILES_TO_ZIP

Upload the a new apk along with the zip file in the google play console.

The following is example code to set the dataSource of a MediaPlayer object from the zip file. Notice how I include FOLDER_WITH_FILES_TO_ZIP/ as part of the path to the .mp3 file. That's crucial.

        soundFileName = "test_file.mp3";
        soundFileName = "FOLDER_WITH_FILES_TO_ZIP/" +soundFileName;
try{
            // Get a ZipResourceFile representing a specific expansion file
            ZipResourceFile expansionFile = APKExpansionSupport.

            //Get the zip file with main obb file version 7 and no patch obb file    
            getAPKExpansionZipFile(MainActivity.this.getApplicationContext(),7,0);

            //Get the asset file descriptor
            AssetFileDescriptor assetFileDescriptor = expansionFile.getAssetFileDescriptor(soundFileName);

            //Set the dataSource
            mediaPlayer.setDataSource(assetFileDescriptor.getFileDescriptor(), assetFileDescriptor.getStartOffset(), assetFileDescriptor.getLength());                
        }

        catch (IllegalArgumentException e) { e.printStackTrace();   }
        catch (IllegalStateException e) { e.printStackTrace();}
        catch (IOException e) {e.printStackTrace(); }

Answer 2

Try to create expansion file using this command

$ jobb -d pathToFolder -o fileName.obb -k secret-key -pn packageName -pv 1

For more details see This