import com.ibm.icu.util.Calendar ;
import com.ibm.icu.util.ChineseCalendar ;

/**
* 양음력간 변환
*
* 사용법>>
*  LunarCalendar lc = new LunarCalendar() ;
*  String lunarDate = lc.toLunar("20021023") ;
*  String date = lc.fromLunar("20020918") ;
*/
public class LunarCalendar {

private Calendar cal ;
private ChineseCalendar cc ;


public LunarCalendar() {
 // default TimeZone, Locale 을 사용..
 cal = Calendar.getInstance() ;
 cc = new ChineseCalendar();
}

/**
* 양력(yyyyMMdd) -> 음력(yyyyMMdd)
*
*/
public synchronized String toLunar( String yyyymmdd ) {
 if(  yyyymmdd == null )
  return "" ;

 String date = yyyymmdd.trim() ;
 if( date.length() != 8 ) {
  if( date.length() == 4 ) 
   date = date + "0101" ;
  else if( date.length() == 6 )
   date = date + "01" ;
  else if( date.length() > 8 )
   date = date.substring(0,8) ;
  else
   return "" ;
 }

 cal.set( Calendar.YEAR, Integer.parseInt(date.substring(0,4)) ) ;
 cal.set( Calendar.MONTH, Integer.parseInt(date.substring(4,6))-1 ) ;
 cal.set( Calendar.DAY_OF_MONTH, Integer.parseInt(date.substring(6)) ) ;

 cc.setTimeInMillis( cal.getTimeInMillis() ) ;

 // ChinessCalendar.YEAR 는 1~60 까지의 값만 가지고 , ChinessCalendar.EXTENDED_YEAR 는 Calendar.YEAR 값과 2637 만큼의 차이를 가집니다.
 int y = cc.get(ChineseCalendar.EXTENDED_YEAR)-2637 ;
 int m = cc.get(ChineseCalendar.MONTH)+1 ;
 int d = cc.get(ChineseCalendar.DAY_OF_MONTH) ;

 StringBuffer ret = new StringBuffer() ;
 if( y < 1000 )
  ret.append( "0" ) ;
 else if( y < 100 )
  ret.append( "00" ) ;
 else if( y < 10 )
  ret.append( "000" ) ;
 ret.append( y ) ;

 if( m < 10 )
  ret.append( "0" ) ;
 ret.append( m ) ;

 if( d < 10 ) 
  ret.append( "0" ) ;
 ret.append( d ) ;

 return ret.toString() ;
}


/**
* 음력(yyyyMMdd) -> 양력(yyyyMMdd)
*
*/
public synchronized String fromLunar( String yyyymmdd ) {
 if(  yyyymmdd == null )
  return "" ;

 String date = yyyymmdd.trim() ;
 if( date.length() != 8 ) {
  if( date.length() == 4 ) 
   date = date + "0101" ;
  else if( date.length() == 6 )
   date = date + "01" ;
  else if( date.length() > 8 )
   date = date.substring(0,8) ;
  else
   return "" ;
 }

 cc.set( ChineseCalendar.EXTENDED_YEAR, Integer.parseInt(date.substring(0,4))+2637 ) ;
 cc.set( ChineseCalendar.MONTH, Integer.parseInt(date.substring(4,6))-1 ) ;
 cc.set( ChineseCalendar.DAY_OF_MONTH, Integer.parseInt(date.substring(6)) ) ;

 cal.setTimeInMillis( cc.getTimeInMillis() ) ;

 int y = cal.get(Calendar.YEAR) ;
 int m = cal.get(Calendar.MONTH)+1 ;
 int d = cal.get(Calendar.DAY_OF_MONTH) ;

 StringBuffer ret = new StringBuffer() ;
 if( y < 1000 )
  ret.append( "0" ) ;
 else if( y < 100 )
  ret.append( "00" ) ;
 else if( y < 10 )
  ret.append( "000" ) ;
 ret.append( y ) ;

 if( m < 10 )
  ret.append( "0" ) ;
 ret.append( m ) ;

 if( d < 10 ) 
  ret.append( "0" ) ;
 ret.append( d ) ;

 return ret.toString() ;
}


}