springboot 递归算法 树状结构

调用

List<Operate> operateTree = new Tree(operateList).buildOperateTree();

实体类

public class Operate {
          
   
    private String id;

    private String name;

    private String parentid;

    private List<Operate> children;
    //省略set和get

Tree类

public class Tree {
          
   
    //操作树
    private List<Operate> operateList;
    public Tree(List<Operate> operateList,List<Resources> resourcesList) {
          
   
        this.operateList = operateList;
    }

    //建立树形结构
    public List<Operate> buildOperateTree(){
          
   
        List<Operate> operateTree =new  ArrayList<>();
        for(Operate operateNode : getOperateRootNode()) {
          
   
            operateNode=buildOperateChildTree(operateNode);
            operateTree.add(operateNode);
        }
        return operateTree;
    }

    //递归，建立子树形结构
    private Operate buildOperateChildTree(Operate pNode){
          
   
        List<Operate> childMenus =new ArrayList<>();
        for(Operate menuNode : operateList) {
          
   
            if(menuNode.getParentid().equals(pNode.getId())) {
          
   
                childMenus.add(buildOperateChildTree(menuNode));
            }
        }
        pNode.setChildren(childMenus);
        return pNode;
    }

    //获取根节点
    private List<Operate> getOperateRootNode() {
          
   
        List<Operate> rootMenuLists =new  ArrayList<>();
        for(Operate menuNode : operateList) {
          
   
            //根节点默认为空字符串
            if(menuNode.getParentid().equals("")) {
          
   
                rootMenuLists.add(menuNode);
            }
        }
        return rootMenuLists;
    }
}