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

¡¾×ª¡¿Java³ÌÐòÐÔÄÜÓÅ»¯

Ò»¡¢±ÜÃâÔÚÑ­»·Ìõ¼þÖÐʹÓø´ÔÓ±í´ïʽ
ÔÚ²»×ö±àÒëÓÅ»¯µÄÇé¿öÏ£¬ÔÚÑ­»·ÖУ¬Ñ­»·Ìõ¼þ»á±»·´¸´¼ÆË㣬Èç¹û²»Ê¹Óø´ÔÓ±í´ïʽ£¬¶øÊ¹Ñ­»·Ìõ¼þÖµ²»±äµÄ»°£¬³ÌÐò½«»áÔËÐеĸü¿ì¡£
Àý×Ó£º
import java.util.Vector;
class CEL {
    void method (Vector vector) {
        for (int i = 0; i < vector.size (); i++)  // Violation
            ; // ...
    }
}
¸üÕý£º
class CEL_fixed {
    void method (Vector vector) {
        int size = vector.size ()
        for (int i = 0; i < size; i++)
            ; // ...
    }
}
¶þ¡¢Îª'Vectors' ºÍ 'Hashtables'¶¨Òå³õʼ´óС
JVMΪVectorÀ©³ä´óСµÄʱºòÐèÒªÖØÐ´´½¨Ò»¸ö¸ü´óµÄÊý×飬½«Ô­Ô­ÏÈÊý×éÖеÄÄÚÈݸ´ÖƹýÀ´£¬×îºó£¬Ô­ÏȵÄÊý×éÔÙ±»»ØÊÕ¡£¿É¼ûVectorÈÝÁ¿µÄÀ©´óÊÇÒ»¸öÆÄ·Ñʱ¼äµÄÊ¡£
ͨ³££¬Ä¬ÈϵÄ10¸öÔªËØ´óСÊDz»¹»µÄ¡£Äã×îºÃÄÜ׼ȷµÄ¹À¼ÆÄãËùÐèÒªµÄ×î¼Ñ´óС¡£
Àý×Ó£º
import java.util.Vector;
public class DIC {
    public void addObjects (Object[] o) {
        // if length > 10, Vector needs to expand
        for (int i = 0; i< o.length;i++) {   
            v.add(o);   // capacity before it can add more elements.
        }
    }
    public Vector v = new Vector();  // no initialCapacity.
}
¸üÕý£º
×Ô¼ºÉ趨³õʼ´óС¡£
    public Vector v = new Vector(20); 
    public Hashtable hash = new Hashtable(10);
²Î¿¼×ÊÁÏ£º
Dov Bulka, "Java Performance and Scalability Volume 1: Server-Side Programming
Techniques" Addison Wesley, ISBN: 0-201-70429-3 pp.55 – 57
Èý¡¢ÔÚfinally¿éÖйرÕStream
³ÌÐòÖÐʹÓ


Ïà¹ØÎĵµ£º

JAVA²Ù×÷XMLµÄÍêÕûÀý×Ó——W3C DOMƪ

ÕâÊÇÒ»¸öÓÃJAVA W3C DOM ½øÐÐXML²Ù×÷µÄÀý×Ó£¬°üº¬Á˲éѯ¡¢Ôö¼Ó¡¢Ð޸ġ¢É¾³ý¡¢±£´æµÄ»ù±¾²Ù×÷¡£½ÏÍêÕûµÄÃèÊöÁËÒ»¸öXMLµÄÕû¸ö²Ù×÷Á÷³Ì¡£ÊʺϸÕÈëÃÅJAVA XML²Ù×÷µÄÅóÓѲο¼ºÍѧϰ¡£
¼ÙÉèÓÐXMLÎļþ£ºtest1.xml
<?xml version="1.0" encoding="UTF-8"?>
<books>
 <book>
  <name>¹þÀï²¨Ì ......

JAVA¹æÔò Öм¶Æª

±¾ÎĽéÉܵÄJAVA¹æÔòµÄ˵Ã÷·ÖΪ3¸öÖ÷Òª¼¶±ð£¬Öм¶ÊÇÆ½Ê±¿ª·¢ÓõıȽ϶àµÄ¼¶±ð£¬ÔÚ½ñºó½«Â½ÐøÐ´³öÆäËûµÄ¹æÔò¡£×ñÊØÁËÕâЩ¹æÔò¿ÉÒÔÌá¸ß³ÌÐòµÄЧÂÊ¡¢Ê¹´úÂëÓÖ¸üºÃµÄ¿É¶ÁÐԵȡ£
£¨1£©    ÔÚfinally·½·¨Àï¹Øµôinput»òÕßoutput ×ÊÔ´
ÔÙ·½·¨ÌåÀïÃæ¶¨ÒåÁËinput»òÕßoutputÁ÷µÄ»°£¬ÐèÒªÔÚfinallyÀïÃæ°ÑËü¹Øµô¡£
ÒÔÏÂ ......

JAVAͨ¹ýJNIµ÷ÓÃDLLÎÊÌâ

×î½üÒªÔÚÒ»¸öJAVA¹¤³ÌÖе÷ÓÃÒ»¸ö±ðÈ˵ÄDLL¿â£¬³öÏÖÁËÒÔÏÂÎÊÌ⣺ƽ̨ÊÇJDK1.6.0_2
±ðÈ˵ÄDLLµ¼³öµÄº¯ÊýÀàËÆÓÚ_Java_Sth_1Find@12 £¬¶øÎÒ·ÃÎʸú¯ÊýµÄÀàÈç¹ûÔÚdefault packageϾͿÉÒÔÕý³£·ÃÎÊ£¬¾ÍÊÇ˵DLLµ¼³öµÄJNIÊÇÔÚĬÈϰüÏµģ¬¶øÈç¹û°Ñ¸ÃÀà·ÅÈëÌØ¶¨µÄ°üϾͻá³öÏÖException in thread "main" java.lang.UnsatisfiedLink ......

JMM JavaµÄÄÚ´æÄ£ÐÍ

JavaµÄÄÚ´æÄ£ÐÍJMM£¨Java Memory Model£©JMMÖ÷ÒªÊÇΪÁ˹涨ÁËÏ̺߳ÍÄÚ´æÖ®¼äµÄһЩ¹ØÏµ¡£¸ù¾ÝJMMµÄÉè¼Æ£¬ÏµÍ³´æÔÚÒ»¸öÖ÷ÄÚ´æ(Main Memory)£¬JavaÖÐËùÓÐʵÀý±äÁ¿¶¼´¢´æÔÚÖ÷´æÖУ¬¶ÔÓÚËùÓÐÏ̶߳¼Êǹ²ÏíµÄ¡£Ã¿ÌõÏ̶߳¼ÓÐ×Ô¼ºµÄ¹¤×÷ÄÚ´æ(Working Memory)£¬¹¤×÷ÄÚ´æÓÉ»º´æºÍ¶ÑÕ»Á½²¿·Ö×é³É£¬»º´æÖб£´æµÄÊÇÖ÷´æÖбäÁ¿µÄ¿½±´£¬»º´ ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ