com.yunmel.syncretic.utils.biz.TreeUtils.java Source code

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Here is the source code for com.yunmel.syncretic.utils.biz.TreeUtils.java

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/*
 * Copyright (c) 2016 yunmle.com(?).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.yunmel.syncretic.utils.biz;

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

import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.Converter;

import com.google.common.collect.Maps;
import com.yunmel.syncretic.bean.BaseEntity;
import com.yunmel.syncretic.utils.commons.CollectionsUtils;

/**
 * 
 * @description 
 *
 * @author xuyq - chainisit@126.com
 * @since 1.0 - 2016715
 */
@SuppressWarnings({ "unchecked" })
public class TreeUtils {

    /**
     * ??List? (listcopy)
     * 
     * @param list
     * @return
     */
    public static <T extends BaseEntity> List<T> toTreeNodeList(List<T> source, Class<T> bean) {
        final Map<String, T> nodes = Maps.newHashMap();
        ConvertUtils.register(new Converter() {
            @SuppressWarnings("hiding")
            @Override
            public <T> T convert(Class<T> arg0, Object arg1) {
                // TODO Auto-generated method stub
                return null;
            }
        }, java.util.Date.class);
        // copy?list?
        List<T> list = CollectionsUtils.copyTo(source, bean);
        // ?
        for (T node : list) {
            node.put("level", -1);
            node.put("hasChild", false);
            node.put("children", new ArrayList<T>());
            nodes.put(node.getString("id"), node);
        }

        final BaseEntity root = new BaseEntity();
        root.put("level", 0);
        root.put("children", new ArrayList<T>());
        root.put("hasChild", false);
        nodes.put("0", (T) root);

        for (T node : list) {
            final T parent = nodes.get(node.getString("parentId"));
            if (parent == null) {
                ((ArrayList<T>) root.get("children")).add(node);
                continue;
                // throw new RuntimeException("?id?");
            } else {
                // ?
                ((List<T>) parent.get("children")).add(node);
            }
        }

        int max = 0;
        for (T node : list) {
            max = Math.max(resolveLevel(node, nodes), max);
        }

        return (List<T>) root.get("children");
    }

    // level
    private static <T extends BaseEntity> int resolveLevel(final T node, final Map<String, T> nodes) {
        // System.out.println(node.getIntValue("level"));
        int level = 1;
        if (node != null) {
            level = node.getIntValue("level");
            if (level == -2) {
                throw new RuntimeException("Node, id=" + node.get("id"));
            }
            if (level == -1) {
                node.put("level", -2);
                level = resolveLevel(nodes.get(node.getString("parentId")), nodes) + 1;
                node.put("level", level);
            } else {
                node.put("hasChild", true);
            }
        }
        return level;
    }

}