write data

import java.io.InputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class FileUtilities {

  public static boolean copyResult;

  public static void saveAssetImage(Context context, String assetName) {
    File fileToWrite = new File(context.getFilesDir(), assetName);
    AssetManager assetManager = context.getAssets();

    try {
      InputStream in = assetManager.open(assetName);
      FileOutputStream out = new FileOutputStream(fileToWrite);
      copyResult = copyFile(in, out);
    } catch(FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  private static boolean copyFile(InputStream in, FileOutputStream out) throws {
    byte[] buffer = new byte[1024];
     int read;
     while((read = in.read(buffer)) != -1) {
       out.write(buffer, 0, read);
     }
  }
}