有关Date问题

[contempomaszxy]

代码如下:
import java.text.SimpleDateFormat;
import java.util.Date;

public class Lesson82 {

/**
* @param args
*/
public static void main(String[] args) {
SimpleDateFormat sdf1=new SimpleDateFormat("yyyyMMDD");
SimpleDateFormat sdf2=new SimpleDateFormat("yyyy年MM月DD日");
Date date=null;
try{
date=sdf1.parse("20031121");
}catch(Exception e){
e.printStackTrace();
}
System.out.println(sdf2.format(date));

}

}

为什么程序输出: 2003年01月21日

[focusforce]

把mm改成小写就正确了。

[focusforce]

或者DD小写

[contempomaszxy]

试了,不行呀,MM与mm出现一样的问题

[focusforce]

Symbol Meaning Presentation Example
G era designator Text AD
y year Number 2009
M month in year Text & Number July & 07
d day in month Number 10
h hour in am/pm (1-12) Number 12
H hour in day (0-23) Number 0
m minute in hour Number 30
s second in minute Number 55
S millisecond Number 978
E day in week Text Tuesday
D day in year Number 189
F day of week in month Number 2 (2nd Wed in July)
w week in year Number 27
W week in month Number 2
a am/pm marker Text PM
k hour in day (1-24) Number 24
K hour in am/pm (0-11) Number 0
z time zone Text Pacific Standard Time
' escape for text Delimiter (none)
' single quote Literal '

[contempomaszxy]

全部变为小写就行了,这是为什么?Java不是规定月与日要用大写吗?

[focusforce]

一般是yyyyMMdd。

[contempomaszxy]

原来与dd有关,多谢

[contempomaszxy]

程序正确写法如下:
import java.text.SimpleDateFormat;
import java.util.Date;

public class Lesson82 {

/**
* @param args
*/
public static void main(String[] args) {
SimpleDateFormat sdf1=new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat sdf2=new SimpleDateFormat("yyyy年MM月dd日");
Date date=null;
try{
date=sdf1.parse("2003-11-21");
}catch(Exception e){
e.printStackTrace();
}
System.out.println(sdf2.format(date));

}

}

[focusforce]

[Quote=引用 7 楼 contempomaszxy 的回复:]
原来与dd有关,多谢
[/Quote]
与格式有关，与"dd"无关，汗一个~

[hellen_99010]

改成这样就行了.你格式时写的日期格式不对.参考下API文档.代码我帮你调好了.

import java.text.SimpleDateFormat;
import java.util.Date;


public class TestDate {
	public static void main(String[] args) {
		SimpleDateFormat sdf1=new SimpleDateFormat("yyyyMMdd");
		SimpleDateFormat sdf2=new SimpleDateFormat("yyyy年MM月dd日");
		Date date=null;
		try{
		date=sdf1.parse("20031121");
		System.out.println(date);
		}catch(Exception e){
		e.printStackTrace();
		}
		System.out.println(sdf2.format(date));

	}

}