Hibernate - 如何坚持'落后'一对多

Question

我有一个有趣的情况。我正在做一个游戏。我有一个带有2d对象'Space'的电路板。每个“空间”都有四个对象'边界'（北，东，南，西）的引用。

空间共享对“边界”的引用。例如，位置（0,0）处的“空间”与位置（1,0）处的“空间”的西边界共享其东边界。这允许我只在事情发生时更新边界（如果被破坏，从墙到无）。

任何想法如何使用Hibernate保持这样的东西？我真的有一对多的边界有很多空格，但我不知道如何将它们特定地与特定的边界（北，南，西，东）联系起来。我也不知道如何设置它以便两个'Space'对象共享对单边界对象的引用。

public class Space {
  private Boundary northBoundry;
  private Boundary eastBoundry;
  private Boundary southBoundry;
  private Boundary westBoundry;

  //hero on the Space
  private HeroBase hero;

  private long     spaceId;

  //getters and setters
}

public class Boundary {

  public static final String NONE        = "none";
  public static final String CLOSED_DOOR = "closed_door";
  public static final String OPEN_DOOR   = "open_door";
  public static final String WALL        = "wall";

  private String             type;
  long                       boundaryId;

  //getters and setters
}

Answer 1

您所描述的是空间与每个边界之间的多对一关系：

public class Space {
  @ManyToOne
  @JoinColumn(name="NORTH_BOUNDARY")
  private Boundary northBoundary;

  @ManyToOne
  @JoinColumn(name="EAST_BOUNDARY")
  private Boundary eastBoundary;

  @ManyToOne
  @JoinColumn(name="SOUTH_BOUNDARY")
  private Boundary southBoundary;

  @ManyToOne
  @JoinColumn(name="WEST_BOUNDARY")
  private Boundary westBoundary;
}