Java将空格替换为逗号

StringBuffer sb = new StringBuffer();
		for (int i = 0; i < text.length(); i++) {
			System.out.println(text.charAt(i));
			if(Character.isWhitespace(text.charAt(i)))
			{
				System.out.println("yes");
				sb.append(",");
			}else
			{
				sb.append(text.charAt(i));
			}
		}
		System.out.println(sb.toString());