springboot创建多级实体

1.创建实体，这是排序的基本字段，其他字段自定义增加

import java.util.List;

import org.springframework.data.annotation.Transient;



public class HierachyDeviceModel {

    private Integer hierachy_id;
    private Integer parent_hid;
    private String parent_name;
    private Integer hierachy;
    
    /**
     * 指定同级别的顺序
     */
    private Integer sort;
    
    /**
     * org.springframework.data.annotation.Transient
     * NOT:javax.persistence.Transient
     */
    @Transient
    private List<HierachyDeviceModel> children;
    
    
    public Integer getHierachy_id() {
        return hierachy_id;
    }
    public void setHierachy_id(Integer hierachy_id) {
        this.hierachy_id = hierachy_id;
    }
    public Integer getParent_hid() {
        return parent_hid;
    }
    public void setParent_hid(Integer parent_hid) {
        this.parent_hid = parent_hid;
    }
    public String getParent_name() {
        return parent_name;
    }
    public void setParent_name(String parent_name) {
        this.parent_name = parent_name;
    }
    public Integer getHierachy() {
        return hierachy;
    }
    public void setHierachy(Integer hierachy) {
        this.hierachy = hierachy;
    }
    public Integer getSort() {
        return sort;
    }
    public void setSort(Integer sort) {
        this.sort = sort;
    }
    public List<HierachyDeviceModel> getChildren() {
        return children;
    }
    public void setChildren(List<HierachyDeviceModel> children) {
        this.children = children;
    }
    
    
}

2.获取树形结构

        //获取所有实体数据
        List<HierachyDeviceModel> hdmList = hdmMongo.findAll();
        
        //获取顶层模型
        List<HierachyDeviceModel> levelTopModel = new ArrayList<HierachyDeviceModel>();
        for(HierachyDeviceModel hdm : hdmList) {
            
            if(hdm.getParent_hid() == 0) {
                levelTopModel.add(hdm);
            }            
        }
        //设置树形结构
        for(HierachyDeviceModel topModel : levelTopModel) {
            
            topModel.setChildren(getChildrens(topModel, hdmList)); //hdmList      
        }
        //对顶层实体数据排序
        levelTopModel.sort(new Comparator<HierachyDeviceModel>() {

            @Override
            public int compare(HierachyDeviceModel o1, HierachyDeviceModel o2) {
            
                 return (o1.getSort() == null ? 0 : o1.getSort()) - (o2.getSort() == null ? 0 : o2.getSort());
            }});
        
        //
        return levelTopModel;

3.实现树形结构

    /**
     * 
     * @param levelTop
     * @param allModels
     * @return
     */
    private List<HierachyDeviceModel> getChildrens(HierachyDeviceModel levelTop, List<HierachyDeviceModel> allModels){
        //
        List<HierachyDeviceModel> children = new ArrayList<HierachyDeviceModel>();
        //递归实现树形结构
        for(HierachyDeviceModel  model : allModels) {
            
            if(model.getParent_hid().equals(levelTop.getHierachy_id())) {
                model.setChildren(getChildrens(model, allModels));
                
                children.add(model);
            }            
        }
        //对每层进行排序
        children.sort(new Comparator<HierachyDeviceModel>() {

            @Override
            public int compare(HierachyDeviceModel o1, HierachyDeviceModel o2) {
                
                 return (o1.getSort() == null ? 0 : o1.getSort()) - (o2.getSort() == null ? 0 : o2.getSort());
            }});
        
        return children;
    }

4.数据例子