Java enum ö¾ÙÀàÐÍ
Java enum ö¾ÙÀàÐÍ
ö¾ÙÀàÐÍÊÇÒ»¸ö³£Á¿¼¯ºÏµÄÊý¾ÝÀàÐÍ¡£
ÒòΪ¶¼Êdz£Á¿£¬ËùÒÔÒ»¸öö¾ÙÀàÐÍÖеÄ×Ö¶ÎÃû¶¼Òª´óд¡£
ÔÚJAVAÖУ¬Ã¶¾ÙÀàÐ͵͍ÒåÊÇͨ¹ý“enum“¹Ø¼ü×Ö½øÐеġ£ÀýÈçÄãÒª¶¨Òå
Ò»¸ö±íʾһ¸öÐÇÆÚµÄÿһÌìµÄö¾ÙÀàÐÍ£º
public enum Day {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY,
SATURDAY
}
Ç¿ÁÒ½¨Òéµ±ÄãÐèÒª¶¨ÒåÒ»×é³£Á¿Ê±£¬Ê¹ÓÃö¾ÙÀàÐÍ¡£
ÏÂÃæÎÒÃÇÀ´¿´ÔõÑùʹÓÃÉÏÃæ¶¨ÒåµÄÀàÐÍDay£º
public class EnumTest {
Day day;
public EnumTest(Day day){
this.day = day;
}
public void tellItLikeItIs(){
switch(day){
case MONDAY: System.out.println("Mondays are bad."); break;
case FRIDAY: System.out.println("Fridays are better"); break;
case SATURDAY:
case SUNDAY: System.out.println("Weekends are best"); break;
default: System.out.println("Midweek days are so-so.")
}
}
public static void main(String[] args){
EnumTest firstDay = new EnumTest(Day.MONDAY);
firstDay.tellItLikeItIs();
EnumTest thirdDay = new EnumTest(Day.WEDNESDAY);
thirdDay.tellItLikeItIs();
EnumTest fifthDay = new EnumTest(Day.FRIDAY);
fifthDay.tellItLikeItIs();
EnumTest sixthDay = new EnumTest(Day.SATURDAY);
sixthDay.tellItLikeItIs();
EnumTest seventhDay = new EnumTest(Day.SUNDAY);
seventhDay.tellItLikeItIs();
}
}
Êä³ö£º
Mondays are bad.
Midweek days are so-so.
Fridays are better.
Weekends are best.
Weekends are best.
JAVAÖе
Ïà¹ØÎĵµ£º
×ÜÊÇÍü¼Çjava¶ÁдÎļþµÄ´úÂë¾ßÌåÔõôд£¬Ð´ÁËÒ»¸ö¼Ç¼ÈçÏÂ
String filename="mydict.txt";
File file=new File(filename);
//read file
if(file.exists())
{
try
{
BufferedReader br=new BufferedReader(new FileReader(file));
String temp=null;
while((temp=br.readLine())!=null) ......
PO VO BO DTO POJO DAOÃǵĸÅÄî
J2EE¿ª·¢ÖдóÁ¿µÄרҵËõÂÔÓïºÜÊÇÈÃÈËÃÔ»ó£¬ÓÈÆäÊǸúһЩ¸ßÊÖÌÖÂÛÎÊÌâµÄʱºò£¬Èý·ÖÖӾͱ»È˼ÒÂú¿ÚµÄרҵÊõÓïÅçÔÎÁË£¬PO VO BO DTO POJO DAO£¬Ò»´ó¶ÑµÄ¾ÍÀ´ÁË£¨Ìý¹ýÀÏÂÞ¶ÔÕâÖÖÏÖÏóµÄÅúÅеÄÅóÓÑ»á»áÐÄһЦ£©¡£
Ê×ÏÈÉùÃ÷żҲ²»ÊÇʲô¸ßÊÖ£¬ÒÔÏÂ×ܽᶼÊÇ×Ô¼ºµÄÌå»á¡£²»¶ÔÖ®´ ......
ÖÚËùÖÜÖª£¬ÔÚJava¶àÏ̱߳à³ÌÖУ¬Ò»¸ö·Ç³£ÖØÒªµÄ·½Ãæ¾ÍÊÇÏ̵߳Äͬ²½ÎÊÌâ¡£
¹ØÓÚÏ̵߳Äͬ²½£¬Ò»°ãÓÐÒÔϽâ¾ö·½·¨£º
1.
ÔÚÐèҪͬ²½µÄ·½·¨µÄ·½·¨Ç©ÃûÖмÓÈësynchronized¹Ø¼ü×Ö¡£
2.
ʹÓÃsynchronized¿é¶ÔÐèÒª½øÐÐͬ²½µÄ´úÂë¶Î½øÐÐͬ²½¡£
3. ʹÓÃJDK
5ÖÐÌṩµÄjava.util.concurrent.lock°üÖеÄLock¶ÔÏó¡£ ......