项目中学到的

int nResId = res.getIdentifier(String.format("smiley_%d", nIndex), "drawable", strPackageName);

String.format("smiley_%d", nIndex)

正则表达式：

private static Pattern mPattern = Pattern.compile("\\[([a-zA-Z0-9\\u4e00-\\u9fa5]+?)\\]");

Matcher matcher = mPattern.matcher(strMessage);