java计算两个日期间有多少自然周

给定一个开始日期和一个结束日期，开始日期如果是周六或周天，那么这就不算一周。结束日期哪怕是周一也要算是一周。最好能有代码，谢谢！

有点小失误，修改过的

public static int get(Date dtS, Date dtE) {
Calendar calS = Calendar.getInstance();
calS.setTime(dtS);
boolean isMonday = true;
Calendar calE = Calendar.getInstance();
calE.setTime(dtE);
if(calS.get(Calendar.DAY_OF_WEEK)!=Calendar.MONDAY){//不是周一不计入
calS.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
return (int) (Math.ceil((calE.getTimeInMillis()-calS.getTimeInMillis())/(86400000.0*7))-1);

    }else{
        return (int) (Math.ceil((calE.getTimeInMillis()-calS.getTimeInMillis())/(86400000.0*7)));
    }

}

问题问的不太容易理解呀，你是想要只要是从周一开始就算是一周么
public static int get(Date dtS, Date dtE) {
Calendar calS = Calendar.getInstance();
calS.setTime(dtS);

    if(calS.get(Calendar.DAY_OF_WEEK)!=Calendar.MONDAY){//不是周一不计入
        calS.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
    }

    Calendar calE = Calendar.getInstance();
    calE.setTime(dtE);
    return (int) (Math.ceil((calE.getTimeInMillis()-calS.getTimeInMillis())/(86400000.0*7))-1);
}