jdk 版本差异之 DateFormat.getDateInstance()

C:\>java -version
java version "1.6.0_10-rc2"
Java(TM) SE Runtime Environment (build 1.6.0_10-rc2-b32)
Java HotSpot(TM) Client VM (build 11.0-b15, mixed mode, sharing)

  

import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;


public class T {
	
	public static void main(String[] args) {
	      	System.out.println(getNextMonday(new Date(), 1));
	}
	
	// 获得下周星期一的日期  
	public static String getNextMonday(Date date,int weeks) {  
	    int mondayPlus = getMondayPlus(date);  
	    GregorianCalendar currentDate = new GregorianCalendar();  
	    currentDate.setTime(date);
	    currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks);  
	    Date monday = currentDate.getTime();  
	    DateFormat df = DateFormat.getDateInstance();  
	    //DateFormat df = new java.text.SimpleDateFormat("yyyy-MM-dd"); 
	    String preMonday = df.format(monday);  
	    return preMonday;  
	}     
	
	// 获得当前日期与本周一相差的天数  
	private static int getMondayPlus(Date date) {  
	    Calendar cd = Calendar.getInstance(); 
	    cd.setTime(date);
	    // 获得今天是一周的第几天，星期日是第一天，星期二是第二天......  
	    int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK);  
	    if (dayOfWeek == 1) {  
	        return -6;  
	    } else {  
	        return 2 - dayOfWeek;  
	    }  
	}  
}

   输出的是2014-1-20
    在linux版本jdk

java version "1.6.0_29"
Java(TM) SE Runtime Environment (build 1.6.0_29-b11)
Java HotSpot(TM) 64-Bit Server VM (build 20.4-b02, mixed mode)

    输出的是 Jan 20, 2014
    不通版本，不同厂商的jdk有些地方是有一些差异的，，特别是在io.线程相关类。差异有一些。    之前也遇到过。