Java 、Kotlin、JavaScript 把全路径列表转换成树状层级嵌套结构

原创

禅与计算机程序设计艺术 2022-06-12 00:42:45 ©著作权

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问题描述

source:

 /a/b/c/d/e
 /a/b/e/f/g
 /a/b/h
 /a/i/j
 /a/i/k

what I need:

         a
       /   \
      b     i
     /|\   / \
    c e h j   k
    | |
    d f
    | |
    e g

程序源代码

JavaScript

let treeDTO = [];
let array = [
    'a/b/c/d/e',
    'a/b/e/f/g',
    'a/b/h',
    'a/i/j',
    'a/i/k'
];

array.map((item) => {
    let key = item;             // key is the full path
    let nodeArray = key.split('/');           // split the full path with '/'
    // 递归
    let children = treeDTO;

    // 构建根节点
    if (children.length == 0) {
        let root = {
            key: nodeArray[0]
        };
        if (nodeArray.length > 1) {
            root.children = [];
        }
        children.push(root);
    } else {
        // 循环构建子节点
        for (let i in nodeArray) {
            console.log("i:" + i);
            console.log("nodeArray:" + nodeArray);

            let node = {
                key: nodeArray[i]
            };

            if (i != nodeArray.length) {
                node.children = [];
            }

            if (children.length == 0) {
                children.push(node);
            }

            let isExist = false;

            for (let j in children) {
                console.log("j:" + j);

                if (children[j].key == node.key) {
                    if (i != nodeArray.length - 1 && !children[j].children) {
                        children[j].children = [];
                    }
                    children = (i == nodeArray.length - 1 ? children : children[j].children);

                    console.log("children:" + JSON.stringify(children));

                    isExist = true;
                    break;
                }
            }

            if (!isExist) {
                children.push(node);
                if (i != nodeArray.length - 1 && !children[children.length - 1].children) {
                    children[children.length - 1].children = [];
                }
                children = (i == nodeArray.length - 1 ? children : children[children.length - 1].children);
            }

        }
    }
});

console.log(treeDTO);

/* source:
 /a/b/c/d/e
 /a/b/e/f/g
 /a/b/h
 /a/i/j
 /a/i/k

   what I need:

         a
       /   \
      b     i
     /|\   / \
    c e h j   k
    | |
    d f
    | |
    e g
*/

Java

节点是通用泛型数据模型：

import com.alibaba.fastjson.JSON;

import java.util.Arrays;

/**
 * @author: Jack
 * 2020-01-11 00:17
 */
public class Main {
    public static void main(String[] args) {
        Tree<String> forest = new Tree<String>("root");
        Tree<String> current = forest;

        for (String tree :
            Arrays.asList(
                "a/b/c/d/e",
                "a/b/e/f/g",
                "a/b/h",
                "a/i/j",
                "a/i/k")) {


            Tree<String> root = current;

            for (String data : tree.split("/")) {
                current = current.child(data);
            }

            current = root;

        }

        forest.accept(new TreeVisitor());

        System.out.println(JSON.toJSONString(forest));
    }
}


 
import java.util.LinkedHashSet;
import java.util.Set;

/**
 * @author: Jack
 * 2020-01-11 00:13
 */
class Tree<T> implements Visitable<T> {
    // NB: LinkedHashSet preserves insertion order
    private Set<Tree> children = new LinkedHashSet<Tree>();
    private T data;

    Tree(T data) {
        this.data = data;
    }

    public void accept(Visitor<T> visitor) {
        visitor.visitData(this, data);

        for (Tree child : children) {
            Visitor<T> childVisitor = visitor.visitTree(child);
            child.accept(childVisitor);
        }
    }

    Tree child(T data) {
        for (Tree child : children) {
            if (child.data.equals(data)) {
                return child;
            }
        }
        return child(new Tree(data));
    }

    Tree child(Tree<T> child) {
        children.add(child);
        return child;
    }

    public Set<Tree> getChildren() {
        return children;
    }

    public void setChildren(Set<Tree> children) {
        this.children = children;
    }

    public T getData() {
        return data;
    }

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


 
/**
 * @author: Jack
 * 2020-01-11 00:13
 */
interface Visitor<T> {

    Visitor<T> visitTree(Tree<T> tree);

    void visitData(Tree<T> parent, T data);
}

 

/**
 * @author: Jack
 * 2020-01-11 00:13
 */
interface Visitable<T> {

    void accept(Visitor<T> visitor);
}


 

/**
 * @author: Jack
 * 2020-01-11 00:15
 */
class TreeVisitor implements Visitor<String> {
    TreeVisitor() {
    }

    public Visitor<String> visitTree(Tree<String> tree) {
        return new TreeVisitor();
    }

    public void visitData(Tree<String> parent, String data) {
    }
}

Kotlin

自定义具体化的节点模型：

import java.util.*

/**
 * @author: Jack
 * 2020-01-11 02:35
 */
class NavTree : NavVisitable {
    var deptNo = ""
    var deptName = ""
    var hasPermission = false
    var leaf = false
    var children: MutableSet<NavTree> = LinkedHashSet()

    constructor(deptNo: String, deptName: String, hasPermission: Boolean, leaf: Boolean) {
        this.deptNo = deptNo
        this.deptName = deptName
        this.hasPermission = hasPermission
        this.leaf = leaf
    }


    /**
     * 递归遍历
     */
    override fun visit(visitor: NavVisitor) {
        visitor.visitTree(this)
        for (child in children) {
            val childVisitor = visitor.visitTree(child)
            child.visit(childVisitor)
        }
    }


    fun children(data: NavTree): NavTree {
        for (child in children) {
            if (child.deptNo == data.deptNo) {
                return child
            }
        }
        children.add(data)
        return data
    }
}


/**
 * @author: Jack
 * 2020-01-11 00:15
 */
class NavTreeVisitor : NavVisitor {

    override fun visitTree(tree: NavTree): NavVisitor {

        return NavTreeVisitor()
    }

}


/**
 * @author: Jack
 * 2020-01-11 00:13
 */
interface NavVisitable {
    fun visit(visitor: NavVisitor)
}


/**
 * @author: Jack
 * 2020-01-11 00:13
 */
interface NavVisitor {

    fun visitTree(tree: NavTree): NavVisitor
}


   /**
     * 构建导航树
     *  source:
    /a/b/c/d/e
    /a/b/e/f/g
    /a/b/h
    /a/i/j
    /a/i/k

    transform to:

    a
    /   \
    b     i
    /|\   / \
    c e h j   k
    | |
    d f
    | |
    e g
     */
    private fun buildAlibrainNavTree(authorizedDepts: List<DataPermissionDeptDTO>, hasPermissionDeptMap: MutableMap<String, DataPermissionDeptDTO>, deptInfoMap: MutableMap<String, String>): NavTree {
        // 顶级根节点
        var rootNode = NavTree(
                deptNo = "00001",
                deptName = "XXX",
                leaf = false,
                hasPermission = false
        )

        var current = rootNode

        authorizedDepts.map {
            val root = current
            val length = it.deptNoArray.size

            it.deptNoArray.forEachIndexed { index, e ->
                val data = NavTree(
                        deptNo = e,
                        deptName = deptInfoMap[e] ?: "",
                        leaf = (index == length - 1),
                        hasPermission = (hasPermissionDeptMap[e] != null)
                )
                current = current.children(data)
            }

            current = root
        }

        rootNode.visit(NavTreeVisitor())
        return rootNode
    }