Java的二叉树排序以及遍历文件展示文本格式的文件树

package test.sort; 
 
public class BinaryNode { 
 private int value;//current value 
 private BinaryNode lChild;//left child 
 private BinaryNode rChild;//right child 
  
 public BinaryNode(int value, BinaryNode l, BinaryNode r){ 
  this.value = value; 
  this.lChild = l; 
  this.rChild = r; 
 } 
  
 public BinaryNode getLChild() { 
  return lChild; 
 } 
 public void setLChild(BinaryNode child) { 
  lChild = child; 
 } 
 public BinaryNode getRChild() { 
  return rChild; 
 } 
 public void setRChild(BinaryNode child) { 
  rChild = child; 
 } 
 public int getValue() { 
  return value; 
 } 
 public void setValue(int value) { 
  this.value = value; 
 } 
  
 //iterate all node. 
 public static void iterate(BinaryNode root){ 
  if(root.lChild!=null){ 
   iterate(root.getLChild()); 
  } 
  System.out.print(root.getValue() + " "); 
  if(root.rChild!=null){ 
   iterate(root.getRChild()); 
  } 
 } 
  
 /** 
  * add child to the current node to construct a tree. 
  * Time: O( nlog(n) ) 
  * **/ 
 public void addChild(int n){ 
  if(n

package test.io;
//在网上找的，听说还是老字竹原创。代码简洁，但是我费了好大的功副消化
import java.util.ArrayList;
import java.util.List;
public class Folder {
 public Folder(String title) {
  this.title = title;
 }
 private String title;
 private List children = new ArrayList();
 public void addChild(Folder f) {
  children.add(f);
 }
 public List getChildren() {
  return children;
 }
 public void setChildren(List children) {
  this.children = children;
 }
 public String getTitle() {
  return title;
 }
 public void setTitle(String title) {
  this.title = title;
 }
 public String toString(String lftStr, String append) {
  StringBuilder b = new StringBuilder();
  b.append(append + title);
  b.append("/n");
  if (children.size() > 0) {
   for (int i = 0; i