JavaÖеÄÖµ´«µÝºÍµØÖ·´«µÝ
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class TestClass {
/**
* @param args
*/
public static void main(String[] args) {
// TODO ×Ô動Éú³É¤µ¤ì¤¿¥á¥½¥Ã¥É?¥¹¥¿¥Ö
List li = searchCrdNo();
System.out.print("main method now is :"+((Map) li.get(0)).get("AA"));
}
public static List searchCrdNo() {
List li = new ArrayList();
Map ma = new HashMap();
ma.put("AA", "1");
li.add(ma);
Map crdNoMap = (Map) li.get(0);
crdNoMap.put("AA", "22");
System.out.print("now is :"+((Map) li.get(0)).get("AA"));
return li;
}
}
now is :22main method now is :22
×î¼òµ¥µÄÀý×Ó£¬°´Öµ´«µÝµÄÀý×Ó£¡
Ïà¹ØÎĵµ£º
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 ......
1.JavaÔÚÐéÄâ»úÉÏÔËÐÐ
JavaÔ´´úÂë²¢²»ÊDZ»±àÒë³ÉΪÆÕͨµÄ»úÆ÷´úÂë¡£¶øÊDZ»·Òë³ÉΪÐéÄâ»ú¿ÉÒÔÖ´ÐеĴúÂë¡£Ò»¸öJava½âÊÍÆ÷×îÖÕÖ´ÐÐÕâЩ´úÂë¡£ÕâÆäÖÐûÓÐÁ¬½ÓµÄ¹ý³Ì£»½âÊÍÔÚÐèÒªµÄʱºò¶¯Ì¬µÄ¼ÓÔØÒ»Ð©Àࣻ
2.JavaÊÇÍêÈ«ÃæÏò¶ÔÏóµÄ
JavaÊÇÒ»ÖÖÍêÈ«ÃæÏò¶ÔÏóµÄÓïÑÔ¡£ÕâÒâζ×ÅÄã¶ÔÈκÎÒ»¸öJava¶ÔÏóËù×öµÄ¶ ......
1. Ê×ÏÈString²»ÊôÓÚ8ÖÖ»ù±¾Êý¾ÝÀàÐÍ£¬StringÊÇÒ»¸ö¶ÔÏó¡£
¡¡¡¡ÒòΪ¶ÔÏóµÄĬÈÏÖµÊÇnull£¬ËùÒÔStringµÄĬÈÏÖµÒ²ÊÇnull£»µ«ËüÓÖÊÇÒ»ÖÖÌØÊâµÄ¶ÔÏó£¬ÓÐÆäËü¶ÔÏóûÓеÄÒ»Ð©ÌØÐÔ¡£
¡¡¡¡2. new String()ºÍnew String(“”)¶¼ÊÇÉêÃ÷Ò»¸öеĿÕ×Ö·û´®£¬Êǿմ®²»ÊÇnull£»
¡¡¡¡3. String str=”kvill”£»
......
»ù±¾Êý¾ÝµÄÀàÐ͵ĴóСÊǹ̶¨µÄ£¬ÕâÀï¾Í²»¶à˵ÁË¡£¶ÔÓÚ·Ç»ù±¾ÀàÐ͵ÄJava¶ÔÏ󣬯ä´óС¾ÍÖµµÃÉÌȶ¡£
ÔÚJavaÖУ¬Ò»¸ö¿ÕObject¶ÔÏóµÄ´óСÊÇ8byte£¬Õâ¸ö´óСֻÊDZ£´æ¶ÑÖÐÒ»¸öûÓÐÈκÎÊôÐԵĶÔÏóµÄ´óС¡£¿´ÏÂÃæÓï¾ä£º
Object ob = new Object();
ÕâÑùÔÚ³ÌÐòÖÐÍê³ÉÁËÒ»¸öJava¶ÔÏóµÄÉúÃü£¬µ«ÊÇËüËùÕ¼µÄ ......
JavaÐéÄâ»úÖУ¬Êý¾ÝÀàÐÍ¿ÉÒÔ·ÖΪÁ½Àࣺ»ù±¾ÀàÐͺÍÒýÓÃÀàÐÍ¡£»ù±¾ÀàÐ͵ıäÁ¿±£´æÔʼֵ£¬¼´£ºËû´ú±íµÄÖµ¾ÍÊÇÊýÖµ±¾Éí£»¶øÒýÓÃÀàÐ͵ıäÁ¿±£´æÒýÓÃÖµ¡£“ÒýÓÃÖµ”´ú±íÁËij¸ö¶ÔÏóµÄÒýÓ㬶ø²»ÊǶÔÏó±¾Éí£¬¶ÔÏó±¾Éí´æ·ÅÔÚÕâ¸öÒýÓÃÖµËù±íʾµÄµØÖ·µÄλÖá£
»ù±¾ÀàÐͰüÀ¨£ºbyte, short, int, long, char, float, double ......