关键实体:@EntitypublicclassKeyEntity{@Id@GeneratedValue(strategy=GenerationType.TABLE)publicLongid;publicStringhandle;publicbooleanequals(Objecto){KeyEntityoke=(KeyEntity)o;returnhandle!=null?handle.equals(oke.handle):oke.handle==null;}publicinthashCode(){returnhandle!=null?handle.hashCode():0;}}值(v