Java code to unzip Flutter assets

gistfile1.txt

private static void unzipLibs(AssetManager am, String nativeLibraryDir) {
    try {

      File complete = Paths.get(appDir, "mono_libs_complete").toFile();

      if(complete.exists() && !BuildConfig.DEBUG) {
        Log.e(TAG, "Libs have already been unzipped to data directory, skipping unzip...");
        return;
      }

      String baseDir = Paths.get(appDir, "app_flutter").toString();
      byte[] buffer = new byte[BUFFER];
      int count;
      FileOutputStream fout;
      
      Log.e(TAG, "Fetching libfile from assets.");
      InputStream is = am.open(libFile);
      Log.e(TAG, "Creating zip input stream.");
      ZipInputStream zin = new ZipInputStream(is);
      ZipEntry ze = null;
      while ((ze = zin.getNextEntry()) != null) {
        Log.e(TAG, "Extracting " + ze.getName());
        Path dest = Paths.get(baseDir, ze.getName());
        if (ze.isDirectory()) {
          if (!Files.exists(dest))
            Files.createDirectories(dest);
        } else {
          fout = new FileOutputStream(dest.toString());
          while((count = zin.read(buffer, 0, BUFFER)) != -1) { fout.write(buffer, 0, count); }
          zin.closeEntry();
          fout.close();
        }
      }
      zin.close();
      is.close();

      is = new FileInputStream(Paths.get(nativeLibraryDir, "libmonosgen-2.0.so").toString());
      fout = new FileOutputStream(Paths.get(baseDir, "lib", "libmonosgen-2.0.so").toString());
      while((count = is.read(buffer)) != -1){
        fout.write(buffer, 0, count);
      }
      is.close();
      fout.close();
      
      is = new FileInputStream(Paths.get(nativeLibraryDir, "libmono-native.so").toString()); 
      fout = new FileOutputStream(Paths.get(baseDir, "lib", "libmono-native.so").toString());
      while((count = is.read(buffer)) != -1){
        fout.write(buffer, 0, count);
      }
      is.close();
      fout.close();

      complete.createNewFile();
      Log.e(TAG, "Completed unzipping libs.");

    } catch(IOException e) {
      Log.e(TAG, "Error unzipping libs : " + e.toString());
    }
  }