È«Ãæ½âÎöJavaÖеÄStringÊý¾ÝÀàÐÍ
1. Ê×ÏÈString²»ÊôÓÚ8ÖÖ»ù±¾Êý¾ÝÀàÐÍ£¬StringÊÇÒ»¸ö¶ÔÏó¡£
ÒòΪ¶ÔÏóµÄĬÈÏÖµÊÇnull£¬ËùÒÔStringµÄĬÈÏÖµÒ²ÊÇnull£»µ«ËüÓÖÊÇÒ»ÖÖÌØÊâµÄ¶ÔÏó£¬ÓÐÆäËü¶ÔÏóûÓеÄһЩÌØÐÔ¡£
2. new String()ºÍnew String(“”)¶¼ÊÇÉêÃ÷Ò»¸öеĿÕ×Ö·û´®£¬ÊÇ¿Õ´®²»ÊÇnull£»
3. String str=”kvill”£»
String str=new String (“kvill”);µÄÇø±ð£º
ÔÚÕâÀÎÒÃDz»Ì¸¶Ñ£¬Ò²²»Ì¸Õ»£¬Ö»Ïȼòµ¥ÒýÈë³£Á¿³ØÕâ¸ö¼òµ¥µÄ¸ÅÄî¡£
³£Á¿³Ø(constant pool)Ö¸µÄÊÇÔÚ±àÒëÆÚ±»È·¶¨£¬²¢±»±£´æÔÚÒѱàÒëµÄ.classÎļþÖеÄһЩÊý¾Ý¡£Ëü°üÀ¨Á˹ØÓÚÀà¡¢·½·¨¡¢½Ó¿ÚµÈÖеij£Á¿£¬Ò²°üÀ¨×Ö·û´®³£Á¿¡£
¿´Àý1£º
String s0=”kvill”;
String s1=”kvill”;
String s2=”kv” + “ill”;
System.out.println( s0==s1 );
System.out.println( s0==s2 );
½á¹ûΪ£º
true
true
Ê×ÏÈ£¬ÎÒÃÇÒªÖª½á¹ûΪµÀJava»áÈ·±£Ò»¸ö×Ö·û´®³£Á¿Ö»ÓÐÒ»¸ö¿½±´¡£
ÒòΪÀý×ÓÖеÄs0ºÍs1ÖеĔkvill”¶¼ÊÇ×Ö·û´®³£Á¿£¬ËüÃÇÔÚ±àÒëÆھͱ»È·¶¨ÁË£¬ËùÒÔs0==s1Ϊtrue£»¶ø”kv”ºÍ”ill”Ò²¶¼ÊÇ×Ö·û´®³£Á¿£¬µ±Ò»¸ö×Ö·û´®Óɶà¸ö×Ö·û´®³£Á¿Á¬½Ó¶ø³Éʱ£¬Ëü×Ô¼º¿Ï¶¨Ò²ÊÇ×Ö·û´®³£Á¿£¬ËùÒÔs2ҲͬÑùÔÚ±àÒëÆھͱ»½âÎöΪһ¸ö×Ö·û´®³£Á¿£¬ËùÒÔs2Ò²Êdz£Á¿³ØÖДkvill”µÄÒ»¸öÒýÓá£
ËùÒÔÎÒÃǵóös0==s1==s2;
ÓÃnew String() ´´½¨µÄ×Ö·û´®²»Êdz£Á¿£¬²»ÄÜÔÚ±àÒëÆÚ¾ÍÈ·¶¨£¬ËùÒÔnew String() ´´½¨µÄ×Ö·û´®²»·ÅÈë³£Á¿³ØÖУ¬ËüÃÇÓÐ×Ô¼ºµÄµØÖ·¿Õ¼ä¡£
¿´Àý2£º
String s0=”kvill”;
String s1=new String(”kvill”);
String s2=”kv” + new String(“ill”);
System.out.println( s0==s1 );
System.out.println( s0==s2 );
System.out.println( s1==s2 );
½á¹ûΪ£º
false
false
false
Àý2ÖÐs0»¹Êdz£Á¿³ØÖДkvill”µÄÓ¦Óã¬s1ÒòΪÎÞ·¨ÔÚ±àÒëÆÚÈ·¶¨£¬ËùÒÔÊÇÔËÐÐʱ´´½¨µÄжÔÏó”kvill”µÄÒýÓã¬s2ÒòΪÓкó°ë²¿·Önew String(“ill”)ËùÒÔÒ²ÎÞ·¨ÔÚ±àÒëÆÚÈ·¶¨£¬ËùÒÔÒ²ÊÇÒ»¸öд´½¨¶ÔÏó”kvill”µÄÓ¦ÓÃ;Ã÷°×ÁËÕâЩҲ¾ÍÖªµÀΪºÎµÃ³ö´Ë½á¹ûÁË¡£
4. String.intern()£º
ÔÙ²¹³ä½éÉÜÒ»µã£º´æÔÚÓÚ.classÎļþÖеij£Á¿³Ø£¬ÔÚÔËÐÐÆÚ±»JVM×°ÔØ£¬²¢ÇÒ¿ÉÒÔÀ©³ä¡£StringµÄintern()·½·¨¾ÍÊÇÀ©³ä³£Á¿³ØµÄÒ»¸
Ïà¹ØÎĵµ£º
Javaѧϰ´ÓÈëÃŵ½¾«Í¨
Ò»¡¢ JDK (Java Development Kit)
JDKÊÇÕû¸öJavaµÄºËÐÄ£¬°üÀ¨ÁËJavaÔËÐл·¾³£¨Java Runtime Envirnment£©£¬Ò»¶ÑJava¹¤¾ßºÍJava»ù´¡µÄÀà¿â(rt.jar)¡£²»ÂÛʲôJavaÓ¦Ó÷þÎñÆ÷ʵÖʶ¼ÊÇÄÚÖÃÁËij¸ö°æ±¾µÄJDK¡£Òò´ËÕÆÎÕJDKÊÇѧºÃJavaµÄµÚÒ»²½¡£×îÖ÷Á÷µÄJ ......
JAVAÓëSAPÊý¾Ý½»»¥µÄ·½Ê½×ܽá
RFC·½Ê½£ºJava³ÌÐòÖ±½Óͨ¹ýRFC·ÃÎÊSAPµÄ¶ÔÏ󣨻ò³Æº¯Êý£¬¿ÉÄܽз¨²»¶Ô£©
SAP
ÌṩÁËBAPI(Business Application Programming
Interface)£¬BAPIÊÇSAPϵͳ¶ÔÍâÌṩµÄһϵÁнӿÚ,Ö÷ÒªÊÇʹµÚÈý·½³ÌÐòͨ¹ýÕâЩ½Ó¿ÚÀ´Ê¹ÓÃSAP,´Ó¶ø·½±ã¿Í»§¶¨ÖÆijЩ³Ì
Ðò.VB,Java,C,C++µÈ¶¼¿ÉÒÔͨ¹ýBAPIÀ´·ÃÎÊSAP ......
¸øÊý×鸳ֵµÄ±ã½Ý·½Ê½£º String s=reader.nextLine(); char a[]=s.toCharArray();ÕâÑù¾Í²»ÓÃʹÓÃÂé·³µÄforÑ»·À´¸³ÖµÁË
Êä³öÊý×éÄÚÈݵıã½Ý·½Ê½£ºString code=new String(a); //aÊÇÒ»¸öÊý×éÃû
System.out.println("ÔÎÄÊÇ"+code);
&nb ......
import
java.util.Random;
/**
*
ÅÅÐò²âÊÔÀà
*
*
ÅÅÐòËã·¨µÄ·ÖÀàÈçÏ£º
*
1.
²åÈëÅÅÐò£¨Ö±½Ó²åÈëÅÅÐò¡¢ÕÛ°ë²åÈëÅÅÐò¡¢Ï£¶ûÅÅÐò£©£»
*
2.
½»»»ÅÅÐò£¨Ã°ÅÝÅÝÅÅÐò¡¢¿ìËÙÅÅÐò£©£»
*
3.
Ñ¡ÔñÅÅÐò£¨Ö±½ÓÑ¡ÔñÅÅÐò¡¢¶ÑÅÅÐò£©£»
  ......
/**
* ´¦Àíʱ¼äÒì³£ Date to String
* Èç¹ûת»»³öÏÖÒì³£»á¸øĬÈÏÖµ00:00
* @param time
* @param sdf
* @return
*/
public static String handleDateParseException(Object time){
String tempTime = "00:00";
try{
......