String today = someSimpleDateFormat.format(new Date());
Calendar rightNow = Calendar.getInstance();
int hour = rightNow.get(Calendar.HOUR_OF_DAY);
int minute = rightNow.get(Calendar.MINUTE);
String hourString = String.valueOf(hour);
String minuteString = String.valueOf(minute);
if(hourString.length() == 1){
hourString = '0'.concat(hourString);
}
if(minuteString.length() == 1){
minuteString = '0'.concat(minuteString);
}
String dayHourMinute = today.concat("_").concat(hourString).concat("_").concat(minuteString);
我本来可以使用'+'运算符。如果我在程序中有很多字符串连接,并且在'concat'方法上使用'+'运算符,或反之亦然,会不会有任何性能问题?用于字符串连接的'+'运算符的Concat
只是一个*注* char' – 2009-12-07 13:55:55