Extensions.java

package com.unity3d.plugin.obbExtensions;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;

import java.io.*;

public class Extensions
{
    private Context context;

    public Extensions(Context context)
    {
        this.context = context;
    }

    public boolean CanReadObb(boolean primaryOnly)
    {
        // Primary dir check
        if (CanReadObbFileFromDir(context.getObbDir())) {
            return true;
        }
        if (primaryOnly) {
            return false;
        }

        // All other shared/external checks
        for (File file : context.getObbDirs()) {
            if (CanReadObbFileFromDir(file)) {
                return true;
            }
        }

        return false;
    }

    public boolean CanReadObbFileFromDir(File dir)
    {
        if (dir == null) {
            return false;
        }

        return CanReadObbFile(GetObbPathFromDir(dir));
    }

    public boolean CanReadObbFile(String path)
    {
        if (path == null) {
            return false;
        }

        try {
            new BufferedReader(new FileReader(path));
            return true;
        } catch (IOException e) {
            return false;
        }
    }

    public String GetObbPathFromDir(File dir)
    {
        if (dir == null) {
            return null;
        }

        return dir.getAbsolutePath() + File.separator + GetObbFileName();
    }

    public String GetObbFileName()
    {
        int versionCode = 0;

        try {
            PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
            versionCode = packageInfo.versionCode;
        }catch (PackageManager.NameNotFoundException ex) { }

        return "main." + String.valueOf(versionCode) + "." + context.getPackageName() + ".obb";
    }

    public String GetPrimaryObbPath()
    {
        return GetObbPathFromDir(context.getObbDir());
    }

    public String[] GetAllObbPaths()
    {
        File[] files = context.getObbDirs();
        String[] paths = new String[files.length];

        for (int n = 0; n < files.length; ++n) {
            paths[n] = GetObbPathFromDir(files[n]);
        }

        return paths;
    }
}