treeiterator.java

用JAVA实现的对动态树状信息的管理。操作员可以通过IE浏览器查看整个树形结构信息

package com.socialite.bizlogic.tree;

import java.util.Iterator;

import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreeNode;

/**JDK没有提供JTree的迭代器，所以我实现了DefaultTreeModel的迭代器
 * @author 余志昌
 */
public class TreeIterator implements Iterator {
	DefaultTreeModel dtm;
	TreeNode curNode;
	boolean started;
	public TreeIterator(DefaultTreeModel dtm) {
		this.dtm= dtm;
	}
	/**
	 * 设置当前位置
	 * @param current 空表示从树根开始（含），否则从current开始（不含）
	 */
	public void setCurrentPos(TreeNode current){
		if(current==null)
			started=false;
		else{
			started=true;
			curNode=current;
		}
	}
	public void remove() {
		// TODO Auto-generated method stub
		dtm.removeNodeFromParent((MutableTreeNode)curNode);
	}
	public boolean hasNext() {
		// TODO Auto-generated method stub
		TreeNode current=curNode;
		if(!started){
			current= (TreeNode)dtm.getRoot();
			if(current==null)
				return false;
			else 
				return true;
		}
		current=curNode;
		if (current.getChildCount() > 0) {
			return true;
		} else {//寻找current的兄弟
			TreeNode parent= current.getParent();
			while (parent!=null) {
				int count= parent.getChildCount();
				int index= parent.getIndex(current);
				if (index < count - 1) 
					return true;
				current=parent;
				parent=parent.getParent();
			}
			return false;
		}
	}

	public Object nextNode() {
		// TODO Auto-generated method stub
		if(!started){
			started=true;
			curNode= (TreeNode)dtm.getRoot();
			return curNode;
		}
		if (curNode.getChildCount() > 0) {
			curNode= curNode.getChildAt(0);
			return curNode;
		} else {//寻找curNode的兄弟
			TreeNode parent= curNode.getParent();
			while (parent!=null) {
				int count= parent.getChildCount();
				int index= parent.getIndex(curNode);
				if (index < count - 1) {
					curNode= parent.getChildAt(index+1);
					return curNode;
				}
				curNode=parent;
				parent=parent.getParent();
			}
			return null;
		}
	}
	/**
	 * 单元测试。树结构：
	 * root\
	 * 		node1\
	 * 			node11
	 * 			node12
	 * 		node2
	 * 		node3\
	 * 			node31
	 * 			node32
	 * 			node33
	 * 期望输出：
	 * -root-node1-node11-node12-node2-node3-node31-node32-node33
	 * @param args 无意义
	 */
	public static void main(String[] args){
		DefaultMutableTreeNode root=new DefaultMutableTreeNode("root");
		DefaultMutableTreeNode node1=new DefaultMutableTreeNode("node1");
		DefaultMutableTreeNode node11=new DefaultMutableTreeNode("node11");
		DefaultMutableTreeNode node12=new DefaultMutableTreeNode("node12");
		DefaultMutableTreeNode node2=new DefaultMutableTreeNode("node2");
		DefaultMutableTreeNode node21=new DefaultMutableTreeNode("node21");
		DefaultMutableTreeNode node22=new DefaultMutableTreeNode("node22");
		DefaultMutableTreeNode node23=new DefaultMutableTreeNode("node23");
		root.add(node1);
		node1.add(node11);
		node1.add(node12);
		root.add(node2);
		node2.add(node21);
		node2.add(node22);
		node2.add(node23);
		JTree tree=new JTree(root);
		DefaultTreeModel dtm=(DefaultTreeModel)tree.getModel();
		Iterator it=new TreeIterator(dtm);
		while(it.hasNext()){
			System.out.print("-"+it.nextNode());
		}
	}

}