apollo-common/src/main/java/com/ctrip/framework/apollo/common/entity/BaseEntity.java/BaseEntity/prePersist
class BaseEntity:  @PrePersist
  protected void prePersist() {
    if (this.dataChangeCreatedTime == null) {
        dataChangeCreatedTime = new Date();
    }
    if (this.dataChangeLastModifiedTime == null) {
        dataChangeLastModifiedTime = new Date();
    }
  }