使用hibernate实现树形结构无限级分类

继承关系如下，假如要实现国家分类： CountryTree extends BaseTree(abstract class) BaseTree(abstract class) implements Tree(interface) 为节省版面，下面代码去掉了javadocTree.java Java代码 1. /* 2. *实现了树的基本操作，上溯、下溯、子节点的添加/移除和递归查找、对象关联等 3. */4. packagetest.testtree.base; 5. importjava.util.Set; 6. 7. publicinterfaceTree 8. publicStringgetCode(); 9. publicStringgetName(); 10. publicStringgetDescription(); 11. publicTreegetParent(); 12. publicSetgetParents(); 13. publicbooleanisRoot(); 14. publicbooleanisLeaf(); 15. publicbooleanisParentOf(Treetree); 16. publicbooleanisChildOf(Treetree); 17. publicvoidaddChild(Treetree); 18. publicvoidrmChild(Treetree); 19. publicSetgetAllChildren(); 20. publicSetgetChildren(); 21. publicSetgetAllLeaves(); 22. publicvoidaddObject(Objectobj); 23. publicvoidrmObject(Objectobj); 24. publicSetgetObjects(); 25. publicLonggetId(); 26. /* * 实现了树的基本操作，上溯、下溯、子节点的添加/移除和递归查找、对象关联等 */package test.testtree.base;import java.util.Set;public interface Tree public String getCode(); public String getName(); public String getDescription(); public Tree getParent(); public Set getParents(); public boolean isRoot(); public boolean isLeaf(); public boolean isParentOf(Tree tree); public boolean isChildOf(Tree tree); public void addChild(Tree tree); public void rmChild(Tree tree); public Set getAllChildren(); public Set getChildren(); public Set getAllLeaves(); public void addObject(Object obj); public void rmObject(Object obj); public Set getObjects(); public Long getId();BaseTree.java Java代码 1. packagetest.testtree.base; 2. importjava.util.*; 3. 4. publicabstractclassBaseTreeextendsBasePojoimplementsTree 5. protectedStringcode; 6. protectedStringname; 7. protectedStringdescription; 8. protectedBaseTreeparent; 9. protectedSetchildren=newHashSet(); 10. protectedSetobjects=newHashSet(); 11. publicvoidsetCode(Stringcode) 12. this.code=code; 13. 14. abstractpublicStringgetCode(); 15. publicvoidsetName(Stringname) 16. =name; 17. 18. abstractpublicStringgetName(); 19. publicvoidsetDescription(Stringdescription) 20. this.description=description; 21. 22. abstractpublicStringgetDescription(); 23. abstractpublicTreegetParent(); 24. publicbooleanisRoot() 25. return(getParent()=null); 26. 27. publicbooleanisLeaf() 28. return(this.getChildren().size()=0); 29. 30. publicbooleanisParentOf(Treetree) 31. if(tree=null|(BaseTree)tree).equals(this) 32. /*如果对方为空*/33. returnfalse; 34. elseif(this.isLeaf() 35. /*如果自己为叶子,则返回FALSE*/36. returnfalse; 37. elseif(tree.isRoot() 38. /*如果对方为根,返回FALSE*/39. returnfalse; 40. else 41. BaseTreebt=(BaseTree)(tree.getParent(); 42. if(this.equals(bt) 43. /*如果对方的父节点是自己,则返回TRUE*/44. returntrue; 45. else 46. /*判断对方的父节点是否是自己的孩子,进行递归*/47. returnisParentOf(bt); 48. 49. 50. 51. publicbooleanisChildOf(Treetree) 52. return(tree.isParentOf(this); 53. 54. publicvoidaddChild(Treetree) 55. children.add(tree); 56. 57. publicvoidrmChild(Treetree) 58. children.remove(tree); 59. (BaseTree)tree).setParent(null); 60. 61. publicSetgetAllLeaves() 62. Setset_old=this.getAllChildren(); 63. Setset=newHashSet(); 64. set.addAll(set_old); 65. Iteratoritr=set_old.iterator(); 66. while(itr.hasNext() 67. BaseTreebt=(BaseTree)itr.next(); 68. if(!bt.isLeaf() 69. set.remove(bt); 70. 71. 72. returnset; 73. 74. publicSetgetParents() 75. Setparents=newHashSet(); 76. Treep=this.getParent(); 77. if(p!=null) 78. parents.add(p); 79. parents.addAll(p.getParents(); 80. 81. returnparents; 82. 83. 84. publicSetgetAllChildren() 85. Setset=newHashSet(); 86. Stackstack=newStack(); 87. stack.push(this); 88. while(!stack.empty() 89. BaseTreebt=(BaseTree)stack.pop(); 90. set.add(bt); 91. Iteratoritr=bt.getChildren().iterator(); 92. while(itr.hasNext() 93. BaseTreebtchild=(BaseTree)itr.next(); 94. stack.push(btchild); 95. 96. 97. set.remove(this); 98. returnset; 99. 100. abstractpublicSetgetChildren(); 101. publicvoidaddObject(Objectobj) 102. objects.add(obj); 103. 104. publicvoidrmObject(Objectobj) 105. objects.remove(obj); 106. 107. abstractpublicSetgetObjects(); 108. publicvoids