ztree多级数据封装和遍历

 这里主要介绍controller封装ztree参数，具体业务以实际为准,这里controller里封装的数据最好写在service层。

1.前台返回数据的格式

var zNodes =[
               { name:"父节点1 - 展开", open:true,
                   children: [
                       { name:"父节点11 - 折叠",
                           children: [
                               { name:"叶子节点111"},
                               { name:"叶子节点112"},
                               { name:"叶子节点113"},
                               { name:"叶子节点114"}
                           ]},
                       { name:"父节点12 - 折叠",
                           children: [
                               { name:"叶子节点121"},
                               { name:"叶子节点122"},
                               { name:"叶子节点123"},
                               { name:"叶子节点124"}
                           ]},
                       { name:"父节点13 - 没有子节点", isParent:true}
                   ]},
               { name:"父节点2 - 折叠",
                   children: [
                       { name:"父节点21 - 展开", open:true,
                           children: [
                               { name:"叶子节点211"},
                               { name:"叶子节点212"},
                               { name:"叶子节点213"},
                               { name:"叶子节点214"}
                           ]},
                       { name:"父节点22 - 折叠",
                           children: [
                               { name:"叶子节点221"},
                               { name:"叶子节点222"},
                               { name:"叶子节点223"},
                               { name:"叶子节点224"}
                           ]},
                       { name:"父节点23 - 折叠",
                           children: [
                               { name:"叶子节点231"},
                               { name:"叶子节点232"},
                               { name:"叶子节点233"},
                               { name:"叶子节点234"}
                           ]}
                   ]},
               { name:"父节点3 - 没有子节点", isParent:true}

           ];

2.封装的类

package com.stuwork.crowdfunding.bean;

import java.util.ArrayList;
import java.util.List;

public class Permission {
    private Integer id;

    private Integer pid;

    private String name;

    private String icon;

    private String url;
    private boolean open;
    private boolean checked;
    
    private List<Permission> children = new ArrayList<Permission>();

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Integer getPid() {
        return pid;
    }

    public void setPid(Integer pid) {
        this.pid = pid;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }

    public String getIcon() {
        return icon;
    }

    public void setIcon(String icon) {
        this.icon = icon == null ? null : icon.trim();
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url == null ? null : url.trim();
    }

    public boolean isOpen() {
        return open;
    }

    public void setOpen(boolean open) {
        this.open = open;
    }

    public List<Permission> getChildren() {
        return children;
    }

    public void setChildren(List<Permission> children) {
        this.children = children;
    }

    public boolean isChecked() {
        return checked;
    }

    public void setChecked(boolean checked) {
        this.checked = checked;
    }
}

package com.stuwork.crowdfunding.util;
public class AjaxResult {
    private boolean success;
    private String message;
    private Page page;
    private Object data;
    
    public Page getPage() {
        return page;
    }

    public void setPage(Page page) {
        this.page = page;
    }

    public boolean getSuccess() {
        return success;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public void setSuccess(boolean success) {
        this.success = success;
    }

    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }
    
    
}

3.controller几种返回数据格式封装和优化

package com.stuwork.crowdfunding.manager.controller;

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

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.stuwork.crowdfunding.bean.Permission;
import com.stuwork.crowdfunding.manager.service.PermissionService;
import com.stuwork.crowdfunding.util.AjaxResult;

@Controller
@RequestMapping("/permission")
public class PermissionController {

    @Autowired
    private PermissionService permissionService;
    
    //最终版方式1
    //最终优化版，减少循环的次数
    @ResponseBody
    @RequestMapping("/loadData")
    public Object loadData(){
        AjaxResult result = new AjaxResult();

        try {
            List<Permission> root = new ArrayList<Permission>();
            List<Permission>  permissionList = permissionService.getAllPermission();//根菜单
            Map<Integer,Permission> map = new HashMap<Integer,Permission>();
            for(Permission bean :permissionList){
                map.put(bean.getId(), bean);
            }
            for(Permission bean :permissionList){
                Permission children = bean;
                if(bean.getPid() == 0){
                   root.add(bean);
                }else{
                    Permission parent = map.get(children.getPid());
                    parent.getChildren().add(children);     
                }
            }
            
            result.setData(root);
            result.setSuccess(true);
        } catch (Exception e) {
            result.setSuccess(false);
            result.setMessage("许可树加载失败");
            e.printStackTrace();
        }
        
        return result;
        
    }
　　 //方式2
    @ResponseBody //递归优化
    @RequestMapping("/loadData")
    public Object loadData(){
        AjaxResult result = new AjaxResult();

        try {
            List<Permission> root = new ArrayList<Permission>();
            List<Permission>  permissionList = permissionService.getAllPermission();//根菜单
            
            for(Permission bean :permissionList){
                Permission children = bean;//子菜单
                if(children.getPid() == 0){
                    root.add(bean);
                }else{
                    for(Permission innerPermission:permissionList){
                        if(children.getPid() == innerPermission.getId()){
                            innerPermission.getChildren().add(children);
                            break;
                        }
                    }
                    
                }
            }
            
            
            result.setData(root);
            result.setSuccess(true);
        } catch (Exception e) {
            result.setSuccess(false);
            result.setMessage("许可树加载失败");
            e.printStackTrace();
        }
        
        return result;
        
    }
    //方式3
    //递归，解决多个层次 //效率低，多次调用数据库
    @ResponseBody
    @RequestMapping("/loadData")
    public Object loadData(){
        AjaxResult result = new AjaxResult();

        try {
            List<Permission> root = new ArrayList<Permission>();
            Permission  permission = permissionService.getRootPermission();//根菜单
            root.add(permission);
            getPermissionChildern(permission);
            result.setData(root);
            result.setSuccess(true);
        } catch (Exception e) {
            result.setSuccess(false);
            result.setMessage("许可树加载失败");
            e.printStackTrace();
        }
        
        return result;
        
    }
    /**
     * 递归使用注意事项
     * 1.调用自身
     * 2.范围要不断缩小
     * 3.要有跳出条件
     * @param permission
     */
    private void getPermissionChildern(Permission  permission){
        List<Permission> childrenList = permissionService.getChildrenPermissionByPid(permission.getId());
        permission.setChildren(childrenList);
        for(Permission bean:childrenList){
            getPermissionChildern(bean);
        }
    
    }
    //方式4（这个是demo，没从数据库取数据）
    @ResponseBody
    @RequestMapping("/loadData")
    public Object loadData(){
        AjaxResult result = new AjaxResult();

        try {
            Permission  permission = new Permission();//父菜单
            Permission  permission1 = new Permission();//子菜单
            Permission  permission2 = new Permission();//子菜单
            List<Permission> list = new ArrayList<Permission>();//子菜单
            List<Permission> root = new ArrayList<Permission>();//根菜单
            
            permission.setName("系统权限菜单");
            permission.setOpen(true);
            permission1.setName("控制面板");
            permission2.setName("权限管理");
            list.add(permission1);
            list.add(permission2);
            permission.setChildren(list);
            root.add(permission);
            result.setData(root);
            result.setSuccess(true);
        } catch (Exception e) {
            result.setSuccess(false);
            result.setMessage("许可树加载失败");
            e.printStackTrace();
        }
        
        return result;
        
    }
    //方式5
    @ResponseBody
    @RequestMapping("/loadData")
    public Object loadData(){
        AjaxResult result = new AjaxResult();

        try {
            List<Permission> root = new ArrayList<Permission>();                            
            Permission  permission = permissionService.getRootPermission();//根菜单
            permission.setOpen(true);
            root.add(permission);
            List<Permission> childrenList = permissionService.getChildrenPermissionByPid(permission.getId());
            permission.setChildren(childrenList);
            for(Permission bean :childrenList){
                bean.setOpen(true);
                List<Permission> innerChildrenList = permissionService.getChildrenPermissionByPid(bean.getId());
                bean.setChildren(innerChildrenList);
            }
            result.setData(root);
            result.setSuccess(true);
        } catch (Exception e) {
            result.setSuccess(false);
            result.setMessage("许可树加载失败");
            e.printStackTrace();
        }
        
        return result;
        
    }
}

4.mapper文件方法

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.stuwork.crowdfunding.manager.dao.PermissionMapper">
  <resultMap id="BaseResultMap" type="Permission">
    <id column="id" jdbcType="INTEGER" property="id" />
    <result column="pid" jdbcType="INTEGER" property="pid" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="icon" jdbcType="VARCHAR" property="icon" />
    <result column="url" jdbcType="VARCHAR" property="url" />
  </resultMap>
    <select id="getPermissionByRoleId" resultType="int">
    SELECT permissionid
      FROM t_role_permission 
     WHERE roleid = #{roleid}
  </select>
  <select id="getRootPermission" resultMap="BaseResultMap">
    SELECT id,pid,icon,url,name
      FROM t_permission 
     WHERE pid = 0
  </select>
  <select id="getChildrenPermissionByPid" resultMap="BaseResultMap">
    SELECT id,pid,icon,url,name
      FROM t_permission
     WHERE pid = #{id}
  </select>
  <select id="getAlltPermission" resultMap="BaseResultMap">
    SELECT id,pid,icon,url,name
      FROM t_permission 
  </select>

</mapper>

5.数据库表数据