SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");
String str="20011230";
Date dt=sdf.parse(str,new ParsePosition(0));
long l=dt.getTime();
int day=2;
l=l+2*24*60*60*1000;
Date dt1=new Date(l);
String reStr=sdf.format(dt1,"",new FieldPosition(0));
System.out.println(reStr);
String str="20011230";
Date dt=sdf.parse(str,new ParsePosition(0));
long l=dt.getTime();
int day=2;
l=l+2*24*60*60*1000;
Date dt1=new Date(l);
String reStr=sdf.format(dt1,"",new FieldPosition(0));
System.out.println(reStr);
import java.util.*;还有不好意思
l=l+2*24*60*60*1000;
改为
l=l+day*24*60*60*1000;
day就是你要加减的日期
String str="20011230";
Date dt=sdf.parse(str,new ParsePosition(0));
Calendar rightNow = Calendar.getInstance();
rightNow.setTime(dt);
rightNow.add(Calendar.DATE,2);//你要加减的日期
Date dt1=rightNow.getTime();
String reStr=sdf.format(dt1,"",new FieldPosition(0));
System.out.println(reStr);