Android : How to compressed Large String with gzip in android

I try to compressed large string in android Like this:

try {
        String str = "MyLarge String";
          ByteArrayOutputStream rstBao = new ByteArrayOutputStream(str.length());
            GZIPOutputStream zos = new GZIPOutputStream(rstBao);
            zos.write(str.getBytes());
            IOUtils.closeQuietly(zos);

            byte[] bytes = rstBao.toByteArray();

            String compressedString = Base64.encodeToString(bytes, true);
            Log.i("Compressed", compressedString);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

but this code return outofmemory error.

outofmemory return in "Base64.encodeToString(bytes, true);" line

please help me if anyone know that.

Thank You.