/**?A?simple?base64?encoding?and?decoding?utility?class
?*?it?can?also?encode?and?decode?non?ASII?characters?such?as?
?*?Chinese
?*/

/**
?*?This?software?is?provided?“AS?IS“?without?a?warranty?of?any?kind.
?*?anyone?can?use?it?for?freeemails?are?welcomed?concerning?bugs?or
?*?suggestions.
?*/

/**
?*?base64.java.??
?*
?*?@version?1.0?06/19/2001
?*?@author?Wen?Yu?yuwen_66@yahoo.com
?*/
package?cafe.util;

public?final?class?base64
???{

????private?static?final?char[]?base64Map?=??//base64?character?table

?????????{?‘A‘‘B‘‘C‘‘D‘‘E‘‘F‘‘G‘‘H‘‘I‘‘J‘‘K‘‘L‘‘M‘‘N‘
???????????‘O‘‘P‘‘Q‘‘R‘‘S‘‘T‘‘U‘‘V‘‘W‘‘X‘‘Y‘‘Z‘‘a‘‘b‘
???????????‘c‘‘d‘‘e‘‘f‘‘g‘‘h‘‘i‘‘j‘‘k‘‘l‘‘m‘‘n‘‘o‘‘p‘
???????????‘q‘‘r‘‘s‘‘t‘‘u‘‘v‘‘w‘‘x‘‘y‘‘z‘‘0‘‘1‘‘2‘‘3‘
???????????‘4‘‘5‘‘6‘‘7‘‘8‘‘9‘‘+‘‘/‘?}?;
?
??/**?convert?the?platform?dependent?string?characters?to?UTF8?which?can?
????*?also?be?done?by?calling?the?java?String?method?getBytes（“UTF-8“）but?I
	*?hope?to?do?it?from?the?ground?up.
	*/

????private?static?byte[]?toUTF8ByteArray（String?s）?
	{
		?int?ichar;?
		?byte?buffer[]=new?byte[3*（s.length（））];
?????????byte?hold[];
		?int?index=0;
	?????int?count=0;?//count?the?actual?bytes?in?the
	??????????????????????//buffer?array?		?
			?
		?for（int?i=0;i		?{?
		???????ichar?=?（int）s.charAt（i）;

		??	???//determine?the?bytes?for?a?specific?character
			???if（（ichar>=0x0080）&（ichar<=0x07FF））
				?{
				???buffer[index++]?=?（byte）（（6<<5）|（（ichar>>6）&31））;
				???buffer[index++]?=?（byte）（（2<<6）|（ichar&63））;
				???count+=2;
				?}
			??
			???//determine?the?bytes?for?a?specific?character
			???else?if（（ichar>=0x0800）&（ichar<=0x0FFFF））
				?{
				???buffer[index++]?=?（byte）（（14<<4）|（（ichar>>12）&15））;
				???buffer[index++]?=?（byte）（（2<<6）|（（ichar>>6）&63））;
				???buffer[index++]?=?（byte）（（2<<6）|（ichar&63））;
				???count+=3;
				?}
				?
		??????//determine?the?bytes?for?a?specific?character
			???else?if（（ichar>=0x0000）&（ichar<=0x007F））
				?{
???????????????????buffer[index++]?=?（byte）（（0<<7）|（ichar&127））;??
				???count+=1;
				?}

??????????????//longer?than?16?bit?Unicode?is?not?supported
			???else?throw?new?RuntimeException（“Unsupported?encoding?character?length!\n“）;
		?}
?????????hold?=?new?byte[count];
?????????System.arraycopy（buffer0hold0count）;?//trim?to?size
?????????return?hold?;
	}

????public?static?String?encode（String?s）
????{
	?	?byte?buf[]?=?toUTF8ByteArray（s）;
	?????return?encode（buf）;
????}

	public?static?String?encode（byte?buf[]）?
????{?????
?????????StringBuffer?sb?=?new?StringBuffer（）;
?????????String?padder?=?““?;?
			?
?????????if（?buf.length?==?0?）??return?““?;?
???????
?????????//cope?with?less?than?3?bytes?conditions?at?the?end?of?buf
?
		?switch（?buf.length%3）
?????????{
???????????????case?1?:?
???????????????{?
??????????????????padder?+=?base64Map[（（?buf[buf.length-1]?>>>?2?）?&

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????6894??2008-12-19?13:29??base64.java

-----------?---------??----------?-----??----

?????????????????6894????????????????????1