Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

javaÖÐabstractÓëinterface

   abstract  classºÍinterfaceÊÇJavaÓïÑÔÖжÔÓÚ³éÏóÀඨÒå½øÐÐÖ§³ÖµÄÁ½ÖÖ»úÖÆ£¬ÕýÊÇÓÉÓÚÕâÁ½ÖÖ»úÖÆµÄ´æÔÚ£¬²Å¸³ÓèÁËJavaÇ¿´óµÄÃæÏò¶ÔÏóÄÜÁ¦¡£ abstract  classºÍinterfaceÖ®¼äÔÚ¶ÔÓÚ³éÏóÀඨÒåµÄÖ§³Ö·½Ãæ¾ßÓкܴóµÄÏàËÆÐÔ£¬ÉõÖÁ¿ÉÒÔÏà»¥Ìæ»»£¬Òò´ËºÜ¶à¿ª·¢ÕßÔÚ½øÐгéÏóÀඨÒåʱ¶ÔÓÚ abstract  classºÍinterfaceµÄÑ¡ÔñÏԵñȽÏËæÒâ¡£Æäʵ£¬Á½ÕßÖ®¼ä»¹ÊÇÓкܴóµÄÇø±ðµÄ£¬¶ÔÓÚËüÃǵÄÑ¡ÔñÉõÖÁ·´Ó³³ö¶ÔÓÚÎÊÌâÁìÓò±¾ÖʵÄÀí½â¡¢¶ÔÓÚÉè¼ÆÒâͼµÄÀí½âÊÇ·ñÕýÈ·¡¢ºÏÀí¡£±¾ÎĽ«¶ÔËüÃÇÖ®¼äµÄÇø±ð½øÐÐÒ»·¬ÆÊÎö£¬ÊÔͼ¸ø¿ª·¢ÕßÌṩһ¸öÔÚ¶þÕßÖ®¼ä½øÐÐÑ¡ÔñµÄÒÀ¾Ý¡£
 
    Ò»¡¢Àí½â³éÏóÀà abstract classºÍinterfaceÔÚJavaÓïÑÔÖж¼ÊÇÓÃÀ´½øÐгéÏóÀࣨ±¾ÎÄÖеijéÏóÀಢ·Ç´Óabstract class·­Òë¶øÀ´£¬Ëü±íʾµÄÊÇÒ»¸ö³éÏóÌ壬¶øabstract classΪJavaÓïÑÔÖÐÓÃÓÚ¶¨Òå³éÏóÀàµÄÒ»ÖÖ·½·¨£¬Çë¶ÁÕß×¢ÒâÇø·Ö£©¶¨ÒåµÄ£¬ÄÇôʲôÊdzéÏóÀ࣬ʹÓóéÏóÀàÄÜΪÎÒÃÇ´øÀ´Ê²Ã´ºÃ´¦ÄØ£¿ÔÚÃæÏò¶Ô ÏóµÄ¸ÅÄîÖУ¬ÎÒÃÇÖªµÀËùÓеĶÔÏó¶¼ÊÇͨ¹ýÀàÀ´Ãè»æµÄ£¬µ«ÊÇ·´¹ýÀ´È´²»ÊÇÕâÑù¡£²¢²»ÊÇËùÓеÄÀà¶¼ÊÇÓÃÀ´Ãè»æ¶ÔÏóµÄ£¬Èç¹ûÒ»¸öÀàÖÐûÓаüº¬×ã¹»µÄÐÅÏ¢À´Ãè»æÒ»¸ö¾ßÌåµÄ¶ÔÏó£¬ÕâÑùµÄÀà¾ÍÊdzéÏóÀà¡£³éÏóÀàÍùÍùÓÃÀ´±íÕ÷ÎÒÃÇÔÚ¶ÔÎÊÌâÁìÓò½øÐзÖÎö¡¢Éè¼ÆÖеóöµÄ³éÏó¸ÅÄÊǶÔһϵÁп´ÉÏÈ¥²»Í¬£¬µ«ÊDZ¾ÖÊÉÏÏàͬµÄ¾ßÌå¸ÅÄîµÄ³éÏó¡£±ÈÈ磺Èç¹ûÎÒÃǽøÐÐÒ»¸öͼÐα༭Èí¼þµÄ¿ª·¢£¬¾Í»á·¢ÏÖÎÊÌâÁìÓò´æÔÚ×ÅÔ²¡¢Èý½ÇÐÎÕâÑùһЩ¾ßÌå¸ÅÄËüÃÇÊDz»Í¬µÄ£¬µ«ÊÇËüÃÇÓÖ¶¼ÊôÓÚÐÎ×´ÕâÑùÒ»¸ö¸ÅÄÐÎ×´Õâ¸ö¸ÅÄîÔÚÎÊÌâÁìÓòÊDz»´æÔڵģ¬Ëü¾ÍÊÇÒ»¸ö³éÏó¸ÅÄî¡£ÕýÊÇÒòΪ³éÏóµÄ¸ÅÄîÔÚÎÊÌâÁìÓòûÓжÔÓ¦µÄ¾ßÌå¸ÅÄËùÒÔÓÃÒÔ±íÕ÷³éÏó¸ÅÄîµÄ³éÏóÀàÊDz»Äܹ»ÊµÀý»¯µÄ¡£ ÔÚÃæÏò¶ÔÏóÁìÓò£¬³éÏóÀàÖ÷ÒªÓÃÀ´½øÐÐÀàÐÍÒþ²Ø¡£ÎÒÃÇ¿ÉÒÔ¹¹Ôì³öÒ»×é¹Ì¶¨ÐÐΪµÄ³éÏóÃèÊö£¬µ«ÊÇÕâ×éÐÐΪȴÄܹ»ÓÐÈÎÒâ¸ö¿ÉÄܵľßÌåʵÏÖ·½Ê½¡£Õâ¸ö³éÏóÃèÊö¾ÍÊdzéÏóÀ࣬¶ø¾ßÌåʵÏÖÔò±íÏÖΪÅÉÉúÀࡣģ¿é¿ÉÒÔ²Ù×÷Ò»¸ö³éÏóÌå¡£ÓÉÓÚÄ£¿éÒÀÀµÓÚÒ»¸ö¹Ì¶¨µÄ³éÏóÌ壬Òò´ËËü¿ÉÒÔÊDz»ÔÊÐíÐ޸ĵģ»Í¬Ê±£¬Í¨¹ý´ÓÕâ¸ö³éÏóÌåÅÉÉú£¬Ò²¿ÉÀ©Õ¹´ËÄ£¿éµÄÐÐΪ¹¦ÄÜ¡£ÊìϤOCPµÄ¶ÁÕßÒ»¶¨ÖªµÀ£¬ÎªÁËÄܹ»ÊµÏÖÃæÏò¶ÔÏóÉè¼ÆµÄÒ»¸ö×îºËÐĵÄÔ­ÔòOCP(Open-Closed Principle)£¬³éÏóÀàÊÇÆäÖеĹؼüËùÔÚ¡£
   
    ¶þ¡¢´ÓÓï·¨¶¨Òå²ãÃæ¿´abstract classºÍinterface ÔÚÓï·¨²ãÃæ£¬JavaÓïÑÔ¶ÔÓÚabstract classºÍinterface¸ø³öÁË


Ïà¹ØÎĵµ£º

¼¸¸öjavaÀàµÄÇø±ð

JavaÃæÊÔÖУ¬×î³£±»ÈËÎʵ½µÄ¼¸¸öÎÊÌ⣺
1. java.util.*°üµÄUML½á¹¹Í¼¡£
2. VectorºÍArrayList¡¢LinkedListÇø±ð  Hashtable ºÍ HashMapÖ®¼äµÄÇø±ð
3. String¡¢StringBuffer£¬StringBuilderÖ®¼äÇø±ð¡£
--»Ø´ð--
1.
Collection
  |
  |_List
  |  |_LinkedList
  |  | ......

ʵÏÖJavaÁ¬½Ómysql£¨Ô´Â룩£¡

JavaÁ¬½ÓmysqlÊý¾Ý¿â£¬´úÂë¾­¹ýÔËÐÐ׼ȷÎÞÎó¡£
ÏÂÃæÎªÊµÀý---->
ÓÃÊý¾Ý¿â²Ù×ݹ¤¾ß£¨Àý£ºSQLyogEnt£©²Ù×Ýmysql½¨±í£¬»òdosϽ¨£¬ÈçÏ£º
Êý¾Ý¿âÃû£ºscutcs
±íÃû£ºstudent
±íÄÚÈÝ£º
sno  char[7]  NO NULL Primary Key;
sname  varchar[8]  NO NULL;
sex  char[2]  NO NULL; ......

JavaÃæÊÔÌâÒ»(»ù´¡)

1. ÈçºÎµÃµ½JavaÓ¦ÓóÌÐòµÄ¿ÉÓÃÄڴ棿
´ð£ºÈçÏ´úÂëʵÏÖÈ¡µÃ×ܵÄÄÚ´æ´óСºÍ¿ÉÓÃÄÚ´æ´óС£¬²¢´òÓ¡µ½¿ØÖÆÌ¨ÉÏ
public class MemoryExp {
public static void main(String[] args) {
System.out.println("Total Memory"+Runtime.getRuntime().totalMemory());
System.out.println("Free Memory ......

javaÈÕÆÚ´¦ÀíSystem£¨1£©

È¡µÃµ±Ç°ÏµÍ³Ê±¼ä   System.currentTimeMillis()
·µ»ØºÁÃëʱ¼ä£¬ÎªlongÐÍÕûÊý£¬
¸Ãº¯ÊýÔÚ½øÐÐϵͳÐÔÄÜ¼à¿ØÊ±×î³£Óõ½
Àý£º
  long start = System.currentTimeMillis();
  //Òª¼à¿ØµÄ´úÂë¶Î
  long end = System.currentTimeMillis();
  System.out.println(end-start);
ÓÐʱҪ¼à¿Øµ ......

javaʱ¼äÈÕÆÚ´¦ÀíDateÀࣨ2£©

ÀàÃû£º
    java.util.Date
¹¹Ôì·½·¨£º
¹¹Ôì·½·¨ ½â˵
Date()
ÎÞ²ÎÊýµÄ¹¹Ôì·½·¨£¬½«¹¹½¨Ò»¸ö±£³Öµ±Ç°ÈÕÆÚ.ʱ¼äµÄDate¶ÔÏó¡£
Date(long time)
²ÎÊýΪ1970Äê1ÔÂ1ÈÕ00ʱ00·Ö00ÃëÆðËù¾­¹ýµÄºÁÃëÊý£¬½«¹¹½¨Ò»¸ö±£³Ö¸ÃÈÕÆÚ.ʱ¼äµÄ¾«È·µ½ºÁÃëµÄDate¶ÔÏó¡£
ÆäËûÓÐЩ¹¹Ôì·½·¨ÒѾ­²»ÍƼöʹÓã¬ÕâÀï² ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ