Java C# base64 <-> string

try 
{
	// JAVA : string -> base64
	{
		String text = "한글";
		byte[] data = text.getBytes("UTF-8");
		String base64 = Base64.encodeToString(data, Base64.DEFAULT);
		Log.d("Unity", "base64="+base64);
	}
  
	// JAVA : base64 -> string
	{
	    String base64 = "YWJjZGVmZw==";
	    byte[] data = base64.getBytes("UTF-8");
	    data = Base64.decode(data, Base64.DEFAULT);
	    String text = new String(data, "UTF-8");
	    Log.d("Unity", "text="+text);
	}
      
}
catch (UnsupportedEncodingException e)
{
	e.printStackTrace();
}


{
	// C# : base64 -> string
	string text = "7ZWc6riA";
	byte[] data = System.Convert.FromBase64String(text);
	string decode_base64 = System.Text.Encoding.UTF8.GetString(data);
	Debug.LogError("decode_base64="+decode_base64);
	
	// C# : base64 -> string
	text = decode_base64;
	data = System.Text.Encoding.UTF8.GetBytes(text);
	string encode_base64 = System.Convert.ToBase64String(data);
	Debug.LogError("encode_base64="+encode_base64);
}

which Jar are you referring to in java when you say Base64.encodeToString
since i see syntax change when i use Apache Library.
or are you using the util one?