JavaÖеÄÉÏÏÂתÐÍ
¼ûϱߵijÌÐò¶Î
package test;
class A {
public String f(A obj)
{
return("A");
}
}
class B extends A {
public String f(B obj)
{
return("C");
}
public String f(A obj)
{
return("D");
}
}
ÎÒÃÇʹÓÃ×ÓÀà´´½¨Ò»¸ö¶ÔÏó£º
B b = new B();
È»ºóÔÙ½«Õâ¸ö×ÓÀàµÄÒýÓ÷ŵ½¸¸Àà¶ÔÏóÖУº
A a;
a = b;
ÄÇôÕâ¸ö¸¸Àà¶ÔÏóaÊÇ×ÓÀà¶ÔÏóbµÄÉÏתÐͶÔÏ󣬶ÔÏóµÄʵÌåÓÉ×ÓÀฺÔð½¨Á¢£¬ÊµÖÊ»¹ÊÇ×ÓÀֻ࣬ÊÇËðʧÁËһЩ¹¦ÄܶøÒÑ£¬ÕâÑùµÄµÃʧ¾ßÌåÈçÏ£º
µÃ£ºÉÏתÐͶÔÏó¿ÉÒÔ²Ù×÷ºÍʹÓÃ×ÓÀà¼Ì³Ð»òÕßÖØÐ´µÄ·½·¨¡£
ʧ£ºÉÏתÐͶÔÏóɥʧÁ˶Ô×ÓÀàÐÂÔö³ÉÔ±±äÁ¿»òÐÂÔöµÄ·½·¨µÄ²Ù×÷ºÍʹÓá£
ÄÇôϱߵÄÕâ¶Î²âÊÔ´úÂëµÄ´òÓ¡½á¹û¾ÍÊÇ“D”£¬ÒòΪa2Ö»ÄÜÓÐpublic String f(A obj) Õâ¸ö·½·¨ÊÇ¿ÉÒÔÓõġ£
public class TestObj
{
public static void main(String args[])
{ A a1 = new A();
A a2 = new B(); //×ÓÀà¶ÔÏóת»¯Îª¸¸À࣬³ÆÎªÉÏתÐÍ£¬²»ÐèÒªÇ¿ÖÆ×ª»»¡£
B b = new B();
System.out.println(a2.f(b)); //“D”
System.out.println();
if (a2 instanceof B) {
B b1 = (B) a2; //¸¸Àà¶ÔÏóת»¯ÎªÏÂתÐÍ£¬´ËʱÐèҪʹÓÃÇ¿ÖÆ×ª»»£¬´ËʱÐèÒªÏÈÅжÏҪת»»µÄÕâ¸ö¶ÔÏó£¨Ò²¾ÍÊÇa2Ö¸ÏòµÄÕâ¸ö¶ÔÏó£©ÊDz»ÊÇBÀàµÄʵÀý
System.out.println(b1.f(b));//"C"
 
Ïà¹ØÎĵµ£º
from: http://blog.csdn.net/cool_rain_man/archive/2009/02/16/3895210.aspx
JAVAÔ´ÂëÑ§Ï°ÍøÕ¾
1. java2s http://www.java2s.com/
Õâ¸öÍøÕ¾·Ç³£ºÃ£¬·Ö³ÉÈý´óÀ࣬·Ö±ðÊÇExample¡¢Products¡¢ Articles£¬Ã¿¸ö´óÀàÏÂÓÖ·Ö±ðÉèÐí¶àСÀ࣬»¹ÓÐËÑË÷¹¦ÄÜ£¬ÕâÑù²éÕÒÆðÀ´·Ç³£·½±ã¡£¡£±ÈÈ磬Èç¹ûÒ ......
ÎÊÌ⣺
·þÎñÆ÷ÊÇÓÃjavaдµÄ£¬¿Í»§¶ËÊÇÓÃactionscript(ʹÓÃamf3)дµÄ£¬µ«ÊÇ·þÎñÆ÷¶ËÖ»·¢ËÍÁËÁ½´ÎÐÅÏ¢£¬
¿Í»§¶ËÈ´½ÓÊÕµ½Èý´ÎÊý¾Ý£¬·þÎñÆ÷¶ËÒ²ÊÇͬÑùµÄÎÊÌ⣬½ÓÊÕµ½¿Í»§¶ËµÄÈý´ÎÊý¾Ý£¬µ«Êǿͻ§¶ËÒ²Ö»·¢ÁË
Á½´ÎÐÅÏ¢¡£
ÓÉÓÚsocket´«ÊäÊý¾ÝʱÊǰ´¹Ì¶¨µÄ´óС´«ËÍ×Ö½ÚÊý¾ÝµÄ£¬µ«ÊÇÔÚflash¿Í»§¶Ë¶ÁÈ¡µÄ
ʱºòÊÇ¿¿Ò» ......
String phoneEL="[0-9]{4}-[0-9]{6}";
String urlEl="<a.+href*=*['\"]?.*?['\"]?.*?>";
String emailEl="^[_a-z0-9-]+(.[_a-z0-9-]+)*"+"@[a-z0-9-]+([.][a-z0-9-]+)*$"; ......
½á¹¹Ä£Ê½£¨££©
Adapter(ÊÊÅäÆ÷)
½«Ò»¸öÀàµÄ½Ó¿Úת»»³É¿Í»§Ï£ÍûµÄÁíÍâÒ»¸ö½Ó¿Ú¡£AdapterģʽʹµÃÔ±¾ÓÉÓÚ½Ó¿Ú²»¼æÈݶø²»ÄÜÒ»Æð¹¤×÷µÄÄÇЩÀà¿ÉÒÔÒ»Æð¹¤×÷¡£
Adapter·ÖΪ2ÖÖ:
ÀàÊÊÅäÆ÷ºÍ¶ÔÏóÊÊÅäÆ÷¡£AdapterºÍAdapteeÖ®¼äÊÇis-a¹ØÏµµÄʱºò£¬ÊôÓÚÀàÊÊÅäÆ÷£¬AdapterºÍAdapteeÖ®¼äÊÇhas-a¹ØÏµµÄʱºò£¬ÊôÓÚ¶ÔÏóÊÊÅäÆ÷¡£ ......