javaÖеĹؼü×Ö£¨transient£©
transientÕâ¸ö¹Ø¼ü×Ö²¢²»³£¼û£¬Ö÷ÒªÓ¦ÓÃÔÚjavaµÄÐòÁл¯·½Ãæ¡£ÕâÀïÎÒÔÙ¶à˵£¬×ªÒ»ÆªÀÏÍâµÄÎÄÕ£¬ºÜÉú¶¯£¬ÐÀÉͰÉ
Be Careful With Transient Data
Java's serialization provides an elegant, and easy to use mechanism for making an object's state persistent. While controlling object serialization, we might have a particular object data member that we do not want the serialization mechanism to save.
To turn off serialization on a certain field of an object, we tag that field of the class of our object with the Java's "transient" keyword. This, to low-level parts of the Java virtual machine, is an indication that the transient variable is not part of the persistent state of an object.
First, let's have some backgrounder code with Java's serialization.
Suppose we define a class as:
public class LoggingInfo implements java.io.Serializable
{
private Date loggingDate = new Date();
private String uid;
private transient String pwd;
LoggingInfo(String user, String password)
{
uid = user;
pwd = password;
}
public String toString()
{
String password=null;
if(pwd == null)
{
password = "NOT SET";
}
else
{
password = pwd;
}
return "logon info: \n " + "user: " + uid +
"\n
Ïà¹ØÎĵµ£º
package debug;import java.io.*;import java.lang.Thread;class MyThread extends Thread{ public int x = 0; public void run(){ System.out.println(++x); }}class R implements Runnable{ private int x = 0; public void run(){ System.out.printl ......
¹Ø¼ü×Ö: javaÖÐjxlµ¼³öÊý¾Ýµ½excelµÄÀý×Ó
ÒªÍùxlsÎļþÀïÃæÐ´ÈëÊý¾ÝµÄʱºòÐèҪעÒâµÄÊǵÚһҪн¨Ò»¸öxlsÎļþ
OutputStream os=new FileOutputStream("c:\\excel2.xls" );
ÔÙ½¨ÍêÕâ¸öÎļþµÄʱºòÔÙ½¨Á¢¹¤×÷Îļþ
jxl.write.WritableWorkbook wwb = Workbook.createWorkbook(new File(os));
Èç¹ûÕâ¸öÎļþÒѾ´æÔÚ,ÄÇà ......
ÓÐЩʱºò,ҪдһЩ³ÌÐò,ÔÚ JAVA ÀïÃæºÃÄÑʵÏÖ, µ«Èç¹ûʹÓÃÆäËü±à³ÌÓïÑÔÈ´ÓֱȽÏÈÝÒ×ʱ,ÎÒÃDz»·Áͨ¹ý JNI À´Èò»Í¬ÓïÑԵijÌÐò¹²Í¬Íê³É.
JNI µÄ½Ì³Ì, ÍøÉÏ C µÄ±È½Ï¶à,Java Ò²ÌṩÁË javah.exe Ϊ C ÓïÑ﵀ JNI ³ÌÐòÉú³ÉÍ·Îļþ, Èç¹ûÄãÊÇÒ»¸ö Delphi ±à³ÌÔ±, ÄÜ·ñÈà JAVA Óë Delphi ³ÌÐò½»»¥ÄØ? ´ð°¸Êǿ϶¨µÄ,½ñÌìÎÒÃǾÍÀ´ ......
JNIÊÇJava Native InterfaceµÄËõд¡£´ÓJava 1.1¿ªÊ¼£¬Java Native Interface (JNI)±ê×¼³ÉΪjavaƽ̨µÄÒ»²¿·Ö£¬ËüÔÊÐíJava´úÂëºÍÆäËûÓïÑÔдµÄ´úÂë½øÐн»»¥¡£JNIÒ»¿ªÊ¼ÊÇΪÁ˱¾µØÒѱàÒëÓïÑÔ£¬ÓÈÆäÊÇCºÍC++¶øÉè¼ÆµÄ£¬µ«ÊÇËü²¢²»·Á°ÄãʹÓÃÆäËûÓïÑÔ£¬Ö»Òªµ÷ÓÃÔ¼¶¨ÊÜÖ§³Ö¾Í¿ÉÒÔÁË¡£
ʹÓÃjava ......
×î½üÐèÒªÖÆ×÷java desktop applicationµÄ°²×°³ÌÐò¡£
ºÃ²»ÈÝÒ×ÔÚÍøÉÏdownÁ˸öinstallanywhere9°²×°²¢ÆÆ½â£¬ ÓÃÆðÀ´»¹Í¦Ë³Àû£¬¹¦ÄܱȽÏÇ¿´ó£¬Ðí¶àµØ·½¿ÉÒÔ¶¨ÖÆ£¬µ±È»×ö³öÀ´µÄ³ÌÐòÔÚ°²×°Ê±Ò²Ëæ´¦¿É¼ûinstallanywhereµÄÉíÓ°£¬ÉÌÒµÈí¼þÂû°ì·¨¡£
ºóÀ´³ÌÐòÔÚÔËÐйý³ÌÖУ¬·¢ÏÖ×ÔÒÔΪÉèÖýøÈ¥ÁËjava desktop applicationµÄjreµ ......