java加减日期数据,Java中日期的加减

How can we add or subtract date in java? For instance java.sql.Date and formatted like this: yyyy-MM-dd, how can i Add 5 months from that? I've seen in some tutorial that they are using Calendar, can we set date on it? Please Help.

Example: 2012-01-01 when added 5 months will become 2012-06-01.

PS: I'm a .Net Programmer and slowly learning to Java environment.

解决方案

First of all you have to convert your String date to java.util.Date, than you have to use java.util.Calendar to manipulate dates. It is also possible to do math with millis, but I do not recommend this.

public static void main( final String[] args ) throws ParseException {

final String sdate = "2012-01-01";

final SimpleDateFormat df = new SimpleDateFormat( "yyyy-MM-dd" );

final Date date = df.parse( sdate ); // conversion from String

final java.util.Calendar cal = GregorianCalendar.getInstance();

cal.setTime( date );

cal.add( GregorianCalendar.MONTH, 5 ); // date manipulation

System.out.println( "result: " + df.format( cal.getTime() ) ); // conversion to String

}