生成树形菜单

题记------学习别人的精髓，并加以总结，消化吸收，这就是提高！！！

       动态生成树形菜单，前台用easyui实现，非常简单不赘述，主要给出后台java的逻辑代码

package com.gongli.util.entity.treeMenu;



/*
 * 用于封装树形菜单，无具体表与之对应,根节点为-1，节点0，然后父节点0，节点001,父节点001，节点001001,001002,001...依次类推
 */
public class TreeMenu {
    private String parentId;//父节点id   
    private String nodeId;//后代节点id 
    private String perName;//权限名
    private String icon;//显示节点的图标
    private String url;//点击树形菜单的叶子节点时，请求的url路径
    public String getParentId() {
        return parentId;
    }
    public void setParentId(String parentId) {
        this.parentId = parentId;
    }
    public String getNodeId() {
        return nodeId;
    }
    public void setNodeId(String nodeId) {
        this.nodeId = nodeId;
    }
    public String getPerName() {
        return perName;
    }
    public void setPerName(String perName) {
        this.perName = perName;
    }        
    public String getIcon() {
        return icon;
    }
    public void setIcon(String icon) {
        this.icon = icon;
    }
    public String getUrl() {
        return url;
    }
    public void setUrl(String url) {
        this.url = url;
    }
    
    

    
    
    
    
}

package com.gongli.util.treeMenu;

import java.util.List;
import java.util.Map;

import com.gongli.util.entity.treeMenu.TreeMenu;
/**
 *树形菜单工具类接口
 *使用前缀编码，每级增加三个数字，如：第一级 001，第二级001001，第三级001001001,目录根节点为0，目录根节点的父节点为-1
 */
public interface TreeMenuInteferce {
    /** 
     * 将树形菜单封装成树
     * @param list 为树形菜单 
     * @param fid 父id 
     */  
    public List<Map<String,Object>> createTree(List<TreeMenu> list, String fid);
    /** 
     * 递归设置TreeMenu树 
     * @param list 
     * @param fid 
     * @return 
     */  
    public List<Map<String, Object>> createChildren(List<TreeMenu> list, String fid);
    
}

package com.gongli.util.impl.treeMenu;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.gongli.util.entity.treeMenu.TreeMenu;
import com.gongli.util.treeMenu.TreeMenuInteferce;

public class TreeMenuInteferceImpl implements TreeMenuInteferce{
    
    /** 
     * 将树形菜单封装成树
     * @param list 为树形菜单 
     * @param fid 父id 
     */ 
    @Override
    public List<Map<String,Object>> createTree(List<TreeMenu> list, String fid) {  
        //存放转换后数据的集合  
        List<Map<String,Object>> comboTreeList  = new ArrayList<Map<String,Object>>();
        for (int i = 0; i < list.size(); i++) {  
            Map<String, Object> map = null;  
            TreeMenu treeMenu = (TreeMenu) list.get(i);  
            if (treeMenu.getParentId().equals(fid)) {  
                map = new HashMap<String, Object>();  
                //这里必须要将对象角色的id、name转换成Tree在页面的显示形式id、text  
                map.put("id", list.get(i).getNodeId());         //id  
                map.put("text",list.get(i).getPerName());      //权限名  
                map.put("url", list.get(i).getUrl()); 
                map.put("iconCls", list.get(i).getIcon()); 
                map.put("children", createChildren(list, treeMenu.getNodeId()));  
            }  
            if (map != null)  
                comboTreeList.add(map);  
        }  
        return comboTreeList;
    }  
    
    /** 
     * 递归设置TreeMenu树 
     * @param list 
     * @param fid 
     * @return 
     */  
    @Override
    public List<Map<String, Object>> createChildren(List<TreeMenu> list, String fid) {  
        List<Map<String, Object>> childList = new ArrayList<Map<String, Object>>();  
        for (int j = 0; j < list.size(); j++) {  
            Map<String, Object> map = null;  
            TreeMenu treeChild = (TreeMenu) list.get(j);  
            if (treeChild.getParentId().equals(fid)) {  
                map = new HashMap<String, Object>();  
                map.put("id", list.get(j).getNodeId());  
                map.put("text", list.get(j).getPerName());
                map.put("url", list.get(j).getUrl()); 
                map.put("iconCls", list.get(j).getIcon()); 
                List<Map<String, Object>> list2 = createChildren(list, treeChild.getNodeId());
                //此处一定要注意，easyui中当节点为叶子节点时并且state为closed，该叶子节点会加载整个tree，形成死循环，所以要排除
                //给叶子节点赋值state:closed,但给非叶子节点赋值state:closed，则默认关闭除了第一个根节点以外的所有节点
                if(list2.size()>0){
                    map.put("state", "closed"); 
                }
                map.put("children", createChildren(list, treeChild.getNodeId()));  
            }                
            if (map != null)  
                childList.add(map);  
            }  
        return childList;  
    }  
    


}