自己建了一个实体类
public class MissPoint implements Serializable{
private static final long serialVersionUID = -3623219494524321164L;
/*** 时间*/
private String date;
/*** 酒店数 */
private Integer count;
/*** 酒店id*/
private List hotelList;
/**需要查询的时间**/
private Date occurDate;
/**所有漏点的数据**/
private List maps ;
private Map> data = new HashMap>();
public MissPoint() {
// TODO Auto-generated constructor stub
}
public MissPoint(Date date,List maps) {
// TODO Auto-generated constructor stub
this.occurDate = date;
this.maps = maps;
}
private void setData(){
for(DataMap map : maps){
int hotelid = map.getInt("hotel_id");
List indexList = DataPointHelper.findByIsZero(map.get("text"), 0, -1);
for(Integer index : indexList){
Date pointDate = DataPointHelper.getTimeByIndex(occurDate, index);
if(data.containsKey(pointDate)){
data.get(pointDate).add(hotelid);
}else{
List list = new ArrayList();
list.add(hotelid);
data.put(pointDate, list);
}
}
}
}
public List getList(){
List missPoints = new ArrayList();
this.setData();
for(Map.Entry> entry : data.entrySet()){
MissPoint point = new MissPoint();
point.setDate(DateHelper.format(entry.getKey(), "yyyy-MM-dd HH:mm:ss"));
point.setCount(entry.getValue().size());
point.setHotelList(entry.getValue());
missPoints.add(point);
}
return missPoints;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((date == null) ? 0 : date.hashCode());
return result;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public Integer getCount() {
return count;
}
public void setCount(Integer count) {
this.count = count;
}
public List getHotelList() {
return hotelList;
}
public void setHotelList(List hotelList) {
this.hotelList = hotelList;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
MissPoint other = (MissPoint) obj;
if (date == null) {
if (other.date != null)
return false;
} else if (!date.equals(other.date))
return false;
return true;
}
@Override
public String toString() {
return "[date=" + date + ", count=" + count
+ ", hotelList=" + hotelList + "]";
}
}
其中给外界提供的方法写成了getList()，转json的时候一直报错，此类的list属性为空，纳闷了，找了半天没有找到名为list的属性，后来突发奇想，是不是那个getList(),让他以为我是获取属性list的值，但是又没有那个属性，所以空指针了，只能这么理解了，不知道对不对，反正改了方法名就不在报错了
Original: https://www.cnblogs.com/Cassie-wang/p/9714539.html
Author: 背着核的桃子
Title: 实体类中方法名尽量避免set,get，报错com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException)
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