为什么同样方式自定义类型，有的可以，有的不可以

public DayDataDTO(String sid, double distance, long steps, double speed,

double calories, long date) {

super();

this.sid = sid;

this.distance = distance;

this.steps = steps;

this.speed = speed;

this.calories = calories;

this.date = date;

}

hql="select new dto.DayDataDTO(sid,sum(distance) as distance,sum(steps) as steps,AVG(speed) as speed,sum(calories) as calories, sum(date) as date) from Score"

+ " where sid='"+sid+"' and date_format(uploadtime,'%Y-%m-%d')=date_format(now(),'%Y-%m-%d') GROUP BY DAY(uploadtime)";

上面就会报错

java.lang.NullPointerException

at org.hibernate.internal.util.ReflectHelper.getConstructor(ReflectHelper.java:355)

而下面的呢，

public DataDTO(long steps, Date uploadtime) {

super();

this.steps = steps;

this.uploadtime = uploadtime;

}

hql="select new dto.DataDTO( sum(steps),uploadtime) from Score where sid='"+sid +"' and"

+ " YEARWEEK(DATE_FORMAT(uploadtime,'%y-%m-%d'))=YEARWEEK(NOW()) GROUP BY DAY(uploadtime)";