使用注解将Date自动转换成Long

public class Date2LongSerializer extends JsonSerializer {


    @Override
    public void serialize(Date date, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
        jsonGenerator.writeNumber(date.getTime() / 1000);
    }
}

    /** 创建时间 **/
    @JsonSerialize(using = Date2LongSerializer.class)
    private Date createTime;