java查询字符在字符串出现的次数

String result="CREATE TABLE `staffinfo` (";
result+="`staffid` int(11) NOT NULL auto_increment,";
result+="`staffname` varchar(200) NOT NULL,";
result+="`ssid` int(11) NOT NULL,";
result+="`spid` int(11) NOT NULL,";
result+="PRIMARY KEY  (`staffid`),";
result+="KEY `FK_ssid` (`ssid`),";
result+="KEY `FK_spid` (`spid`)";
result+=") ENGINE=MyISAM AUTO_INCREMENT=6 DEFAULT CHARSET=utf8";
int num = 0;
Pattern pt = Pattern.compile("FK_",Pattern.CASE_INSENSITIVE);
Matcher mc = pt.matcher(result);
mc.find();
mc.reset();
while(mc.find()){
num++;
}
System.out.println("字符串中 java 出现次数:"+num);