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

Java Annotation dzÎö2

Java»ù´¡-ѧϰʹÓÃAnnotation×¢½â¶ÔÏó
×¢½â(Ò²±»³ÆÎªÔªÊý¾Ý)ΪÎÒÃÇÔÚ´úÂëÖÐÌí¼ÓÐÅÏ¢ÌṩÁËÒ»ÖÖÐÎʽ»¯µÄ·½·¨,ʹÎÒÃÇ¿ÉÒÔÔÚÉÔºóij
¸öʱ¿Ì·Ç³£·½±ãµØÊ¹ÓÃÕâЩÊý¾Ý
 
1-1:»ù±¾Óï·¨
Java SE5ÄÚÖÃÈýÖÖ±ê×¼×¢½â
@Override:±íʾµ±Ç°µÄ·½·¨¶¨Ò彫¸²¸Ç³¬ÀàÖеķ½·¨.Èç¹ûÄ㲻СÐÄÆ´Ð´´íÎó,»òÕß·½·¨Ç©Ãû¶Ô²»Éϱ»¸²
¸ÇµÄ·½·¨,±àÒëÆ÷¾Í»á·¢³ö´íÎóÌáʾ
@Deprecated:Èç¹û³ÌÐòԱʹÓÃÁË×¢½âΪËüµÄÔªËØ,ÄÇô±àÒëÆ÷¾Í»á·¢³ö¾¯¸æÐÅÏ¢
@SupperessWarnings:¹Ø±Õ²»µ±µÄ±àÒëÆ÷¾¯¸æÐÅÏ¢.
Java SE5ÄÚÖÃËÄÖÖԪע½â
@Target:±íʾ¸Ã×¢½â¿ÉÒÔÓÃÓÚʲôµØ·½.¿ÉÄܵÄElementType²ÎÊý°üÀ¨:
1)CONSTRUCTOR:¹¹ÔìÆ÷µÄÉùÃ÷
2)FIELD:ÓòÉùÃ÷(°üÀ¨enumʵÀý)
3)LOCAL_VARIABLE:¾Ö²¿±äÁ¿ÉùÃ÷
4)METHOD:·½·¨ÉùÃ÷
5)PACKAGE:°üÉùÃ÷
6)PARAMETER:²ÎÊýÉùÃ÷
7)TYPE:Àà¡¢½Ó¿Ú(°üÀ¨×¢½âÀàÐÍ)»òenumÉùÃ÷
@Retention:±íʾÐèÒªÔÚʲô¼¶±ð±£´æ¸Ã×¢½âÐÅÏ¢.¿ÉÑ¡µÄRetentionPolicy²ÎÊý°üÀ¨:
1)SOURCE:×¢½â½«±»±àÒëÆ÷¶ªÆú
2)CLASS:×¢½âÔÚclassÎļþÖпÉÓÃ,µ«»á±»VM¶ªÆú
3)RUNTIME:VM½«ÔÚÔËÐÐÆÚÒ²±£Áô×¢½â,Òò´Ë¿ÉÒÔͨ¹ý·´Éä»úÖÆ¶Áȡע½âµÄÐÅÏ¢
@Documented:½«´Ë×¢½â°üº¬ÔÚJavadocÖÐ
@Inherited:ÔÊÐí×ÓÀà¼Ì³Ð¸¸ÀàÖеÄ×¢½â
´ó¶àÊýʱºò,³ÌÐòÔ±Ö÷ÒªÊǶ¨Òå×Ô¼ºµÄ×¢½â£¬²¢±àд×Ô¼ºµÄ´¦ÀíÆ÷À´´¦ÀíËüÃÇ.
----------------------------- UseCase.java -------------------------   
package com;   
  
import java.lang.annotation.ElementType;   
import java.lang.annotation.Retention;   
import java.lang.annotation.RetentionPolicy;   
import java.lang.annotation.Target;   
  
@Target(ElementType.METHOD)//ÓÃÀ´¶¨ÒåÄãµÄ×¢½â½«Ó¦ÓÃÔÚʲôµØ·½,±¾´¦Ó¦ÓÃΪ·½·¨   
//ÓÃÀ´¶¨Òå¸Ã×¢½âÔÚÄÄÒ»¸ö¼¶±ð¿ÉÓÃ,ÔÚÔ´´úÂëÖÐ(source)ÀàÎļþÖÐ(class)»òÕßÔËÐÐʱ(runtime)   
@Retention(RetentionPolicy.RUNTIME)   
public @interface UseCase {   
 public int id();   
 public String description()default "no description";   
}   
  
----------------------------- PasswordUtils .java&nb


Ïà¹ØÎĵµ£º

Java NIO APIÏê½â

 
Java NIO APIÏê½â
ÔÚJDK
1.4ÒÔǰ£¬JavaµÄIO²Ù×÷¼¯ÖÐÔÚjava.ioÕâ¸ö°üÖУ¬ÊÇ»ùÓÚÁ÷µÄ×èÈû£¨blocking£©API¡£¶ÔÓÚ´ó¶àÊýÓ¦ÓÃÀ´Ëµ£¬ÕâÑùµÄAPIʹÓúܷ½
±ã£¬È»¶ø£¬Ò»Ð©¶ÔÐÔÄÜÒªÇó½Ï¸ßµÄÓ¦Óã¬ÓÈÆäÊÇ·þÎñ¶ËÓ¦Óã¬ÍùÍùÐèÒªÒ»¸ö¸üΪÓÐЧµÄ·½Ê½À´´¦ÀíIO¡£´ÓJDK 1.4Æð£¬NIO
API×÷Ϊһ¸ö»ùÓÚ»º³åÇø£¬²¢ÄÜÌṩ·Ç×èÈû(non-blo ......

java±éÀú¶ÔÏó


JDK1.4ÖÐ
Map map = new HashMap();
Iterator it = map.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
Object key = entry.getKey();
Object value = entry.getValue();
}
JDK1.5ÖÐ,Ó¦ÓÃÐÂÌØÐÔFor-EachÑ­»·
Map m = new HashMap(); ......

Java ÀíÂÛÓëʵ¼ù: ÕýȷʹÓà Volatile ±äÁ¿

Java™ ÓïÑÔ°üº¬Á½ÖÖÄÚÔÚµÄͬ²½»úÖÆ£ºÍ¬²½¿é£¨»ò·½·¨£©ºÍ volatile ±äÁ¿¡£ÕâÁ½ÖÖ»úÖÆµÄÌá³ö¶¼ÊÇΪÁËʵÏÖ´úÂëÏ̵߳ݲȫÐÔ¡£ÆäÖÐ Volatile ±äÁ¿µÄͬ²½ÐԽϲµ«ÓÐʱËü¸ü¼òµ¥²¢ÇÒ¿ªÏú¸üµÍ£©£¬¶øÇÒÆäʹÓÃÒ²¸üÈÝÒ׳ö´í¡£ÔÚÕâÆÚµÄ Java ÀíÂÛÓëʵ¼ù
ÖУ¬Brian Goetz ½«½éÉܼ¸ÖÖÕýȷʹÓà volatile ±äÁ¿µÄģʽ£¬²¢Õë¶ÔÆäÊÊÓ ......

Àí½âJavaÀà¼ÓÔØÔ­Àí

µÚÒ»²¿·Ö. Ìáʾ
ÎÒÐèÒª¶ÁÕâÆªÎÄÕÂÂð£¿
JavaÀà¼ÓÔØÆ÷¶ÔJavaϵͳµÄÔËÐÐÊÇÖÁ¹ØÖØÒªµÄ£¬µ«ÊÇÈ´³£³£±»ÎÒÃǺöÂÔ¡£JavaÀà¼ÓÔØÆ÷¸ºÔØ
ÔÚÔËÐÐʱ²éÕҺͼÓÔØÀà¡£×Ô¶¨ÒåÀà¼ÓÔØÆ÷¿ÉÒÔÍêÈ«¸Ä±äÀàµÄ¼ÓÔØ·½Ê½£¬ÒÔ×Ô¼ºÏ²»¶µÄ·½Ê½À´
¸öÐÔ»¯ÄãµÄJavaÐéÄâ»ú¡£±¾ÎļòÒªµÄ½éÉÜJavaÀà¼ÓÔØÆ÷£¬È»ºóͨ¹ýÒ»¸ö¹¹Ôì×Ô¶¨ÒåÀà¼ÓÔØÆ÷
µÄÀý×ÓÀ´ËµÃ÷£¬Õâ ......

java ÖÐ CookieµÄÓ÷¨

Cookie£º¼Ç¼Óû§µÇ½״̬£¬¿ÉÒÔÔÚ¿Í»§¶Ë´´½¨cookie£¬¿ÉÒÔʹÓû§µÚ¶þ´ÎµÇ½µÄʱºò²»ÓÃÊäÈëÓû§ÃûºÍÃÜÂ룬¼´¿ÉÒԵǽµ½Ö÷Ò³
Ö÷Òª´úÂ룺  
LoginView ÖУº £¨»ñÈ¡cookie£©
//»ñÈ¡cookie
Cookie [] cs=request.getCookies();
String name="";
String value="";
if(null!=cs)
......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ