EasyUI_tree根据数据库数据非迭代生成树形结构

 

 

我们经常要根据数据库表的结构，生成树形结构在页面显示；下面就是一个例子：

页面的tree组件采用的是EasyUI 的 Tree 组件。

数据库结构：

表名称： tDict

Id name parentid sortid valid

主键 名称 父ID 排序ID 是否可用

tDict 实体类中，父ID以 tDict 实体类表述，如下：

[java] view plaincopyprint?

1. public class TDict{
3. // Fields
5. private String id;
6. private TDict tDict;
7. private Integer sortid;
8. private String valid;
9. private String name;
13. ……省略<Get & Set>
17. }

public class TDict{ // Fields private String id; private TDict tDict; private Integer sortid; private String valid; private String name; ……省略<Get & Set> }

首先，建立数节点类：

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1. import java.util.ArrayList;
2. import java.util.HashMap;
3. import java.util.List;
4. import java.util.Map;
6. public class TreeNode {
8. privateString id; //要显示的子节点的ID
9. privateString text; //要显示的子节点的 Text
10. privateString iconCls; //节点的图标
11. privateString parentId; //父节点的ID
12. privateList<TreeNode> children; //孩子节点的List
14. publicTreeNode(){}
16. publicTreeNode(String id, String text, String iconCls, String parentId,
18. List<TreeNode>children) {
20. super();
21. this.id= id;
22. this.text= text;
23. this.iconCls= iconCls;
24. this.parentId= parentId;
25. this.children= children;
26. }
30. publicString getId() {
32. returnid;
34. }
36. publicvoid setId(String id) {
37. this.id= id;
38. }
40. publicString getText() {
41. returntext;
42. }
44. publicvoid setText(String text) {
45. this.text= text;
46. }
48. publicString getIconCls() {
49. returniconCls;
50. }
52. publicvoid setIconCls(String iconCls) {
53. this.iconCls= iconCls;
54. }
56. publicString getParentId()
57. returnparentId;
58. }
60. publicvoid setParentId(String parentId) {
61. this.parentId= parentId;
62. }
64. publicList<TreeNode> getChildren() {
65. returnchildren;
66. }
68. publicvoid setChildren(List<TreeNode> children) {
69. this.children= children;
70. }
72. //添加孩子的方法
74. publicvoid addChild(TreeNode node){
75. if(this.children == null){
76. children= new ArrayList<TreeNode>();
77. children.add(node);
78. }else{
79. children.add(node);
80. }
82. }
84. }

import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class TreeNode { privateString id; //要显示的子节点的ID privateString text; //要显示的子节点的 Text privateString iconCls; //节点的图标 privateString parentId; //父节点的ID privateList<TreeNode> children; //孩子节点的List publicTreeNode(){} publicTreeNode(String id, String text, String iconCls, String parentId, List<TreeNode>children) { super(); this.id= id; this.text= text; this.iconCls= iconCls; this.parentId= parentId; this.children= children; } publicString getId() { returnid; } publicvoid setId(String id) { this.id= id; } publicString getText() { returntext; } publicvoid setText(String text) { this.text= text; } publicString getIconCls() { returniconCls; } publicvoid setIconCls(String iconCls) { this.iconCls= iconCls; } publicString getParentId() returnparentId; } publicvoid setParentId(String parentId) { this.parentId= parentId; } publicList<TreeNode> getChildren() { returnchildren; } publicvoid setChildren(List<TreeNode> children) { this.children= children; } //添加孩子的方法 publicvoid addChild(TreeNode node){ if(this.children == null){ children= new ArrayList<TreeNode>(); children.add(node); }else{ children.add(node); } } }

下面是生成树的方法：

[java] view plaincopyprint?

1. @SuppressWarnings("unchecked")
3. public List fillTree(String tableName){
5. String hql = " from TDictt where valid='1' order by t.sortid ";
6. List<TreeNode> list = new ArrayList<TreeNode>();
7. Map map = new HashMap<String, TreeNode>();
9. try {
11. //拉出数据库的数据，放入list2中
13. ArrayList<TDict> list2 = (ArrayList<TDict>)this.find(hql);
15. //将list2中的数据，转换成TreeNode类型，放入Map中备用
16. for (TDict tDict : list2) {
17. TreeNode node = new TreeNode();
18. node.setId(tDict.getId());
19. node.setText(tDict.getName());
20. if(tDict.gettDict()!=null){
21. node.setParentId(tDict.gettDict().getId());
22. }
24. map.put(tDict.getId(), node);
26. }
29. //遍历list2的数据，把每个节点加入他的父节点的孩子List
31. for (TDict tDict : list2) {
33. if(tDict.gettDict()!= null){
35. if(tDict.gettDict().getId() == null)
36. {
37. list.add((TreeNode)map.get(tDict.getId()));
38. }else{
40. String pidString = tDict.gettDict().getId();
41. TreeNode pnode = (TreeNode)map.get(pidString);
42. TreeNode cnode=(TreeNode)map.get(tDict.getId());
43. pnode.addChild(cnode);
44. }
45. }else{
46. list.add((TreeNode)map.get(tDict.getId()));
47. }
48. }
49. }catch (Exception e) {
50. // TODO: handleexception
51. e.printStackTrace();
52. }
53. return list;
55. }

@SuppressWarnings("unchecked") public List fillTree(String tableName){ String hql = " from TDictt where valid='1' order by t.sortid "; List<TreeNode> list = new ArrayList<TreeNode>(); Map map = new HashMap<String, TreeNode>(); try { //拉出数据库的数据，放入list2中 ArrayList<TDict> list2 = (ArrayList<TDict>)this.find(hql); //将list2中的数据，转换成TreeNode类型，放入Map中备用 for (TDict tDict : list2) { TreeNode node = new TreeNode(); node.setId(tDict.getId()); node.setText(tDict.getName()); if(tDict.gettDict()!=null){ node.setParentId(tDict.gettDict().getId()); } map.put(tDict.getId(), node); } //遍历list2的数据，把每个节点加入他的父节点的孩子List for (TDict tDict : list2) { if(tDict.gettDict()!= null){ if(tDict.gettDict().getId() == null) { list.add((TreeNode)map.get(tDict.getId())); }else{ String pidString = tDict.gettDict().getId(); TreeNode pnode = (TreeNode)map.get(pidString); TreeNode cnode=(TreeNode)map.get(tDict.getId()); pnode.addChild(cnode); } }else{ list.add((TreeNode)map.get(tDict.getId())); } } }catch (Exception e) { // TODO: handleexception e.printStackTrace(); } return list; }

在页面显示的时候，把list转换成Json格式：

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1. List treeSet = treeManagerImpl.fillTree(null);
3. String treeString = gson.toJson(treeSet);
5. session.setAttribute("tree", treeString);

List treeSet = treeManagerImpl.fillTree(null); String treeString = gson.toJson(treeSet); session.setAttribute("tree", treeString);

在页面取Json数据，并显示：

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1. <script type="text/javascript">
3. window.onload =function(){
5. tree = ${tree};
7. $('#tt').tree({
9. data:tree
11. });
13. };
15. </script>