org.springframework.statemachine.support.tree.Tree.java Source code

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Here is the source code for org.springframework.statemachine.support.tree.Tree.java

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/*
 * Copyright 2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.statemachine.support.tree;

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

/**
 * Utility class which can be used to represent a tree based data structure.
 * This tree utility is not very generic and needs to be used as it's meant to
 * be.
 *
 * @author Janne Valkealahti
 *
 * @param <T> the type of node data
 */
public class Tree<T> {

    private final Node<T> root = new Node<T>(null);
    private final Map<Object, Node<T>> map = new HashMap<Object, Node<T>>();
    private final List<DataWrap<T>> notMapped = new ArrayList<DataWrap<T>>();

    public Node<T> getRoot() {
        return root;
    }

    public void add(T data, Object id, Object parent) {
        notMapped.add(new DataWrap<T>(data, id, parent));
        tryMapping();
    }

    private void tryMapping() {
        int size = notMapped.size();
        Iterator<DataWrap<T>> iter = notMapped.iterator();
        while (iter.hasNext()) {
            DataWrap<T> next = iter.next();
            if (next.parent == null) {
                Node<T> n = new Node<T>(next.data);
                map.put(next.id, n);
                root.getChildren().add(n);
                iter.remove();
            } else {
                if (map.containsKey(next.parent)) {
                    Node<T> n = new Node<T>(next.data);
                    Node<T> node = map.get(next.parent);
                    map.put(next.id, n);
                    node.getChildren().add(n);
                    iter.remove();
                }
            }
        }
        if (notMapped.size() < size) {
            tryMapping();
        }
    }

    public static class Node<T> {
        private final T data;
        private final List<Node<T>> children;

        public Node(T data) {
            this(data, null);
        }

        public Node(T data, List<Node<T>> children) {
            this.data = data;
            this.children = children != null ? children : new ArrayList<Node<T>>();
        }

        public T getData() {
            return data;
        }

        public List<Node<T>> getChildren() {
            return children;
        }

    }

    private static class DataWrap<T> {
        final T data;
        final Object id;
        final Object parent;

        public DataWrap(T data, Object id, Object parent) {
            this.data = data;
            this.id = id;
            this.parent = parent;
        }
    }

}