[置顶] 菜单树的java实现(菜单非递归实现)

菜单树

class ThreeBean{
    private String id; //节点id
    private String parentId; //父节点id
    private String name;  //节点名称
    private List<ThreeBean> children = new ArrayList<ThreeBean>();//子节点
    private Double count; //节点对应的数量
    private Boolean expanded=false;//是否有子节点
    public static void main(String[] args) {
        Map<String,ThreeBean> nodeListMap = new HashMap<String,ThreeBean>();
        ThreeBean root=new ThreeBean("0",null,"根节点",0D);
        nodeListMap.put(root.getId(), root);
        ThreeBean a1=new ThreeBean("1","0","节点1",0D);
        nodeListMap.put(a1.getId(), a1);
        ThreeBean a2=new ThreeBean("2","0","节点2",0D);
        nodeListMap.put(a2.getId(), a2);
        ThreeBean a3=new ThreeBean("3","1","节点3",0D);
        nodeListMap.put(a3.getId(), a3);
        ThreeBean a4=new ThreeBean("4","2","节点4",0D);
        nodeListMap.put(a4.getId(), a4);
        ThreeBean a5=new ThreeBean("5","2","节点5",0D);
        nodeListMap.put(a5.getId(), a5);
        ThreeBean a6=new ThreeBean("6","3","节点6",1D);
        nodeListMap.put(a6.getId(), a6);
        ThreeBean a7=new ThreeBean("7","3","节点7",2D);
        nodeListMap.put(a7.getId(), a7);
        ThreeBean a8=new ThreeBean("8","3","节点8",3D);
        nodeListMap.put(a8.getId(), a8);
        ThreeBean a9=new ThreeBean("9","4","节点9",4D);
        nodeListMap.put(a9.getId(), a9);
        ThreeBean a10=new ThreeBean("10","4","节点10",5D);
        nodeListMap.put(a10.getId(), a10);
        ThreeBean a11=new ThreeBean("11","4","节点11",6D);
        nodeListMap.put(a11.getId(), a11);
        ThreeBean a12=new ThreeBean("12","4","节点12",7D);
        nodeListMap.put(a12.getId(), a12);
        ThreeBean a13=new ThreeBean("13","5","节点13",8D);
        nodeListMap.put(a13.getId(), a13);
        ThreeBean a14=new ThreeBean("14","5","节点14",9D);
        nodeListMap.put(a14.getId(), a14);
        for (String key:nodeListMap.keySet())
        {
            ThreeBean nodeData = nodeListMap.get(key);
            //主键是空的则为根目录 根据自己情况定义根目录
            if (nodeData.getParentId() == null || nodeData.getParentId().equals("")) {
                root = nodeData;
                root.setExpanded(true);
            }
            else
            {
                //根据该目录的父节点组合其子节点集合
                ThreeBean zTreeDataInfo =nodeListMap.get(nodeData.getParentId());
                zTreeDataInfo.getChildren().add(nodeData);
                zTreeDataInfo.setExpanded(true);
            }
        }

//到这里的话 我们就构造了完了 二叉树

        ObjectMapper mapper = new ObjectMapper();
        String json = null;
  root=count(root);
        try {
            json = mapper.writeValueAsString(root);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        System.out.println(json);
    }
private static ThreeBean count(ThreeBean root){//递归给节点赋值
        Double total = root.getCount();
    if(root.getChildren().size() < 1){
        root.setCount(total);
        return root;
    }
    Double sum = total;
    for(ThreeBean child : root.getChildren()){
        ThreeBean tmp = count(child);
        sum += tmp.getCount();
    }
    root.setCount(sum);
    return root;

    }
}

 

总结：这种实现菜单树的方法应该要比递归简单容易理解。