在项目中，可能会遇到机构树这种格式，但是数据库存储的数据 不能维护这样子的树，所以需要中间转换来完成，zTree可以支持pid，id，name的格式，但是easyui貌似不行，这里就给出刚刚码好的代码:
package com.xxx.pojo;
import java.util.ArrayList;
import java.util.List;
public class ComboTree
{
private String id;
private String text;
private String state;
private String pid;
private String clickFlag;
private List<ComboTree> children;
public ComboTree()
{
super();
this.setState("closed");
this.setId("00");
this.setText(null);
this.setClickFlag("off");
this.setChildren(new ArrayList<ComboTree>());
}
public void clear()
{
this.setState("closed");
this.setId(null);
this.setText(null);
this.setChildren(null);
}
@Override
public String toString()
{
StringBuilder sb = new StringBuilder();
sb.append("{"id":"");
sb.append(this.id);
sb.append("","text":"");
sb.append(this.text);
sb.append("","clickFlag":"");
sb.append("off");
sb.append(""");
if (!this.children.isEmpty())
{
sb.append(","state":"");
sb.append(this.state);
sb.append("","children":[");
boolean flag = false;
for (ComboTree c : this.children)
{
if (flag)
sb.append(",");
else
flag = true;
sb.append(c.toString());
}
sb.append("]");
}
sb.append("}");
return sb.toString();
}
public String getPid()
{
return pid;
}
public void setPid(String pid)
{
this.pid = pid;
}
public void addChildren(ComboTree ct)
{
this.children.add(ct);
// System.out.println("add");
}
//添加一个节点
public boolean addNode(ComboTree ct){
//如果需要添加的节点的PID 为当前节点的ID, 则直接
//添加, 返回true
if(this.id == ct.pid ||
(this.id != null && ct.pid != null && this.id.equals(ct.pid))){
this.children.add(ct);
return true;
}
//委托给子节点
for(ComboTree cct: this.children){
if(cct.addNode(ct))
return true;
}
//无法添加成功
return false;
}
public String getId()
{
return id;
}
public void setId(String id)
{
this.id = id;
}
public String getText()
{
return text;
}
public void setText(String text)
{
this.text = text;
}
public String getState()
{
return state;
}
public void setState(String state)
{
this.state = state;
}
public List<ComboTree> getChildren()
{
return children;
}
public void setChildren(List<ComboTree> children)
{
this.children = children;
}
public String getClickFlag()
{
return clickFlag;
}
public void setClickFlag(String clickFlag)
{
this.clickFlag = clickFlag;
}
}
package com.xxx.util;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Set;
import com.abc.pojo.ComboTree;
public class TreeHelper {
/**
* 输入无序的ComboTree 获得 List 类型的森林
* @param list0 无序ComboTree节点
* @return List<ComboTree> 森林
* */
@SuppressWarnings("null")
public static List<ComboTree> makeTree(List<ComboTree> list0) throws Exception{
//以pId为Key,而以pid为相同的ComboTree作为List为Value
Map<String,List<ComboTree>> mapForPid = new HashMap<String,List<ComboTree>>();
//以Id为Tree, 用来快速寻找到RootPID
Map<String,ComboTree> mapForId = new HashMap<String,ComboTree>();
//root pid set
Set<String> rps = new HashSet<String>();
//构造 两种类型的map
for(ComboTree ct : list0){
//构造ID Map
mapForId.put(ct.getId(), ct);
//PID Map 构造
String pid = ct.getPid();
List<ComboTree> lct = mapForPid.get(pid);
if(lct == null){
//构造 Value类型
lct = new LinkedList<ComboTree>();
mapForPid.put(pid, lct);
}
//添加这个节点
lct.add(ct);
}
//制作rootPidSet
{
//已经被寻找过的ID
Set<String> keySet = new HashSet<String>();
//寻找RootPID
for(String key : mapForId.keySet()){
//沿pid 直到rootPID
while(true){
//已经处理过这种节点,
//那么可以肯定该节点所在的rootPid已经被添加
if(keySet.contains(key)){
break;
}
//添加到keySet中, 表示该节点已经被处理
keySet.add(key);
ComboTree ct = mapForId.get(key);
if(ct == null){
//如果ct为null, 则表示该Key就是一个rootPID
rps.add(key);
break;
}
//下一个Pid
key = ct.getPid();
}
}
}
//虚拟root结果树
List<ComboTree> vts = new LinkedList<ComboTree>();
//对所有的root Pid 进行处理
for(String key : rps){
List<String> queue = new LinkedList<String>();
ComboTree vt = new ComboTree();
vt.setId(key);
vt.setPid(null);
vt.setText("虚拟节点");
//添加根Id
queue.add(key);
while(!queue.isEmpty()){
String pid = queue.remove(0);
List<ComboTree> list = mapForPid.get(pid);
//没有pid对应的子树
if(list == null)
continue;
for(ComboTree ct : list){
//添加到queue中
queue.add(ct.getId());
//插入到正确的位置
if(!vt.addNode(ct)){
throw new Exception(ct+"无法插入到Tree中");
}
}
}
vts.add(vt);
}
//整理res结果
List<ComboTree> res = new LinkedList<ComboTree>();
for(ComboTree vct : vts){
//虚拟PID节点不能作为真实根节点
for(ComboTree ct: vct.getChildren()){
//添加真实节点
res.add(ct);
}
}
return res;
}
public static ComboTree getComboTree(String id,String pid,String name){
ComboTree t = new ComboTree();
t.setId(id);
t.setPid(pid);
t.setText(name);
return t;
}
public static void main(String[] args) throws Exception {
List<ComboTree> list = new LinkedList<ComboTree>();
list.add(getComboTree("0",null,"root"));
list.add(getComboTree("1","0","root"));
list.add(getComboTree("2","0","root"));
list.add(getComboTree("3","2","root"));
list.add(getComboTree("4","3","root"));
list.add(getComboTree("5","4","root"));
list.add(getComboTree("6","2","root"));
list.add(getComboTree("A",null,"root"));
list.add(getComboTree("B","A","root"));
list.add(getComboTree("C","A","root"));
list.add(getComboTree("D","B","root"));
list.add(getComboTree("a","aaaaa","root"));
list.add(getComboTree("aa","a","root"));
System.out.println(makeTree(list));
}
}
主要函数为makeTree, 需要ComboTree结构支持.
算法的思想为：
搜索rootPID的集合，然后根据rootPID，构建出虚拟树，注意虚拟树，的root节点是无效的，在返回结果集合的时候需要剔除掉
运行结果:
