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

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

java½Ó¿ÚʵÏÖ

java½Ó¿ÚʵÏÖ
¶Ô³õѧÕßÀ´Ëµ£¬½Ó¿Ú²»ÊǺܺÃÀí½â¡£ÏÖ½«Ä³¸ßÊÖµÄһƪÎÄÕÂÌù³öÀ´£¬¹²´ó¼Ò·ÖÏí£¡
ÎÒÃÇÀ´¿´Ò»¸öÀà
class A {
private int a;
public int getA() {
return a;
}
}
Õâ¸öÀàµÄÊôÐÔÊÇ˽Óеģ¬Íâ½ç²»ÄÜ·ÃÎÊ£¬¶øÍâ½ç¿ÉÒÔͨ¹ý¹«Óз½·¨À´·ÃÎÊÕâ¸öÀà¡£ÎÒÃÇ˵һ¸öÀàµÄ¹«Óз½
·¨¾ÍÊÇÕâ¸öÀàµÄ¶ÔÍâ½Ó¿Ú¡£Í¨³£ ......

JAVAÓëactionscriptͨÐÅ ±ðÈ˵ľ­Ñé

 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» ......

java¹¤×÷Á÷Ïê½â

 ¹¤×÷Á÷»ù±¾¸ÅÄî: ʲôÊǹ¤×÷Á÷£¿
¹¤×÷Á÷£ºÁ½¸ö»òÁ½¸öÒÔÉϵÄÈË£¬ÎªÁ˹²Í¬µÄÄ¿±ê£¬Á¬ÐøµÄÒÔ´®Ðлò²¢Ðеķ½Ê½È¥Íê³ÉijһҵÎñ¡£
ÒµÎñ£º¹¤×÷Á÷ËùÖ¸ÒµÎñº­¸ÇÁËÓë¾­ÓªÏà¹ØµÄ»î¶¯¡£
¡¡¡¡´®Ðлò²¢ÐУºÒµÎñÖеIJ½ÖèÒ²ÐíÒÔÒ»²½½Ó×ÅÒ»²½µÄ·½Ê½½øÐУ¬ÎÒÃdzÆÖ®Îª´®ÐУ»»òÕßÓɲ»Í¬µÄÈË»ò×éºÏ¸ù¾Ý²»Í¬µÄÇé¿ö´¦Àí£¬ÎÒÃdzÆÖ®Îª²¢ÐС ......

Oracle Functionµ÷ÓÃjava´úÂë

 Ô­ÎÄ´«ËÍÃÅ£ºhttp://www.blogjava.net/improviser/archive/2008/12/07/244911.html
ÔÚǰһƪÎÄÕÂÖмòµ¥½éÉÜÁËJAVA³ÌÐòÈçºÎµ÷ÓÃOracle´æ´¢¹ý³ÌµÄ»ù±¾Óï·¨³ÌÐò½á¹¹£¬ ±¾ÎĽ«½éÉÜJAVA¸úOracleµÄÁíÒ»ÖÖ¹ØÏµ£¬¼´Í¨¹ýJAVA±àдOracle´æ´¢¹ý³Ì¡£ ͨ³£Çé¿öÏ£¬ÎÒÃǶ¼ÊÇʹÓÃOracleÊý¾Ý¿âϵͳÖеÄps/sqlÓï¾äÀ´Îªoracle±àд ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ