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 javaÖÐnullµÄ¸ÅÄî:javaÖУ¬null±íʾÀà»ò±äÁ¿Êǿգ¬²»´ú±íÈκζÔÏó»òʵÀý£¬¿ÉÒÔ½«null¸³¸øÒýÓÃÀàÐͱäÁ¿£¬µ«²»¿ÉÒÔ½«null¸³¸ø»ù±¾ÀàÐͱäÁ¿¡£Êý¾Ý¿âÖÐNULLµÄ¸ÅÄî:Êý¾Ý¿âÖУ¬null±íʾδÌîд¡¢Î´Öª¡¢²»¿ÉÓõĸÅÄºÍjava²»Í¬µÄÊÇÊý¾Ý¿âÖпÉÒÔ½«null¸³¸øÈκÎÊý¾ÝÀàÐÍ¡£ÕâÑùÒ»À´£¬ÎÒÃÇ´ÓÊý¾Ý¿âÖжÁÈ¡×ֶεÄÖµºó£¬ÔÚjava³ÌÐòÖÐÈçºÎÅж϶ÁÈ¡µÄÖµÊÇ·ñΪnullÄØ£¿ÓÃx==null·½·¨Âð£¿ÏÔÈ»²»ÐУ¬³ý·ÇÕâ¸öXÊÇStringÀàÐ͵ġ£ResultSetÖеÄwasNull()·½·¨¿ÉÒÔ½â¾öÕâ¸öÎÊÌâ:
wasNull():±¨¸æ×îºóÒ»¸ö¶ÁÈ¡µÄÁÐÊÇ·ñ¾ßÓÐÖµ SQL NULL¡£×¢Ò⣬±ØÐëÊ×ÏȶÔÁе÷ÓÃÒ»¸ö»ñÈ¡·½·¨³¢ÊÔ¶ÁÈ¡ÆäÖµ£¬È»ºóµ÷Óà wasNull ·½·¨²é¿´¶ÁÈ¡µÄÖµÊÇ·ñΪ SQL NULL¡£
 È磺String value="";
       int n;
       while(rs.next()){
        value=rs.getString("name");
        if(rs.wasNull()){
         System.out.println("null");
        }else{
         System.out.println(value);
        }
        
        n=rs.getInt("number");
        if(rs.wasNull()){
         System.out.println("null");
        }else{
         System.out.println(n);
        }
       } 


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Javaʼþ´¦ÀíµÄ4ÖÖ·½·¨

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import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
/**
*Javaʼþ´¦Àí»úÖÆ:×ÔÉíÀà×÷Ϊʼþ¼àÌýÆ÷
*@author Winty(wintys@gmail.com)
*@version 2008-12-3
*/
class ThisClassEvent extends JFrame implements ActionListener{
JButton btn;
public ......

JAVA µ¼³öCSV´úÂë

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import au.com.bytecode.opencsv.CSVWriter;
public class CsvDemo {
    
    public static void main(String[] args) throws IOException {
        
     ......

Java²Ù×÷Microsoft WordÖ®jacob (2)

 ÕâÀïÓÐÒ»¸öMSWordManager À࣬ÊÇjacob¹Ù·½·¢²¼µÄ¹¤¾ßÀ࣬ÀïÃæÓдó¶àÊýJava²Ù×÷MS OfficeµÄ¹¤¾ß¡£
   
 
package com.test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
im ......

Java 2 SDK »·¾³

 
rem ¿´µ½ºÜ¶à³õѧÕß·´¸´ÎÊÕâ¸öÎÊÌ⣬дÁËÒ»¸öºÜ¼òµ¥µÄÒ»¸ö½Å±¾£¬ÓÃÓÚ×Ô¶¯ÉèÖû·¾³±äÁ¿¡£°Ñ´úÂ뿽±´£¬Áí´æÎªjavaEnv.bat¡£°²×°ÍêJava 2 SDKÖ®ºó£¬¿ªÒ»¸öÃüÁîÐд°¿Ú,ÊäÈëjavaEnv java2SDKDir(java2SDKDirÊÇÄãµÄjavaµÄ°²×°Ä¿Â¼£¬²»´øÂ·¾¶×îºóµÄ\¡£Èç¹û°²×°Â·¾¶ÖÐÓпոñ£¬ÇëÓÃjavaEnv "java2SDKDir"¸ñʽ)²¢ÔËÐС£(×¢£ºÒ ......

java exception javaÒì³£»ã×Ü2009

java exception ½â¾ö·½°¸ - ÎÒµÄÒì³£Íø|Òì³£|exception|myexception 831 - ActionMessages 832 - could not instantiate id generator 833 - javax.servlet.jsp.JspException 834 - javax.naming.NoInitialContextException 835 - net.sf.hibernate.HibernateException 836 - org.hibernate.exception.GenericJDBCExceptio ......
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