code: public static int count(Pattern pattern, CharSequence content) {
  		if (null == pattern || null == content) {
  			return 0;
  		}
  
  		int count = 0;
  		final Matcher matcher = pattern.matcher(content);
  		while (matcher.find()) {
  			count++;
  		}
  
  		return count;
  	}
docs: 计算指定字符串中，匹配pattern的个数
  
  @param pattern 编译后的正则模式
  @param content 被查找的内容
  @return 匹配个数