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<value){    if(lChild!=null){     lChild.addChild(n);    }    else{     lChild = new BinaryNode(n, null, null);    }   }   else{    if(rChild!=null){     rChild.addChild(n);    }    else{     rChild = new BinaryNode(n, null, null);    }   }  }    //test case.  public static void main(String[] args){   System.out.println();   int[] arr = new int[]{23,54,1,65,9,3,100};   BinaryNode root = new BinaryNode(arr[0], null, null);   for(int i=1; i<arr.length; i++){    root.addChild(arr[i]);   }   BinaryNode.iterate(root);  } } 

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<Folder> children = new ArrayList<Folder>(); public void addChild(Folder f) {  children.add(f); } public List<Folder> getChildren() {  return children; } public void setChildren(List<Folder> 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 < children.size() - 1; i++) {    b.append(lftStr+ children.get(i).toString(lftStr + "│ ", "├-"));   }   b.append(lftStr+ children.get(children.size() - 1).toString(lftStr + " ","└-"));  }  return b.toString(); } public static void main(String[] args) {  Folder root = new Folder("菜单列表");  Folder f1 = new Folder("开始菜单");  root.addChild(f1);  Folder f1_1 = new Folder("程序");  f1.addChild(f1_1);  Folder f1_1_1 = new Folder("附件");  f1_1.addChild(f1_1_1);  Folder f1_1_1_1 = new Folder("娱乐");  f1_1_1.addChild(f1_1_1_1);  Folder f1_1_1_2 = new Folder("娱乐2");  f1_1_1.addChild(f1_1_1_2);  Folder f1_2 = new Folder("辅助工具");  f1.addChild(f1_2);  System.out.println(root.toString(" ", "$")); }}//**************************************//经过消化之后我修改的。可打印文件结构import java.io.*; public class DocTree {  File root = null;    public DocTree(File f){   this.root = f;  }   public static void main(String[] args){   File root = new File("c://test");   DocTree tree = new DocTree(root);   System.out.println(tree.toString(" ", ""));  }    public String toString(String leftStr, String append){   StringBuilder b = new StringBuilder();   b.append(append + root.getName());   b.append("/n");  if(!root.isFile()&&root.listFiles().length!=0){    File[] files = root.listFiles();    DocTree[] docTrees = new DocTree[files.length];    for(int i=0; i<docTrees.length; i++){     docTrees[i] = new DocTree(files[i]);    }    for (int i=0; i<files.length-1; i++){     b.append(leftStr + docTrees[i].toString(leftStr+"│", "├"));    }    b.append(leftStr + docTrees[docTrees.length-1].toString(leftStr + " ", "└"));   }   return b.toString();  }}//*****************************************//然后我还是觉得理解起来不方便， 过几天说不定就忘记了，//还是自己写一个， 虽然思想照抄， 但我觉得自己的理解起来很方便。//带注释，import java.io.*;public class Tree { File root = null; public Tree(File f){  this.root = f; } /** test ├1 │├目录1.txt │├目录11 ││├111.txt ││└112.txt │└12 └test.pdf  */ /**  * @param root 当前正在被扫描的根文件  * @param childLeftStr 如果该文件有孩子，childLeftStr  *  表示孩子节点的左面应该打印出来的结构性信息  *  拿上面的例子来说，根结点test的孩子的左面的  *  结构信息为"" 空，结点"目录11"的孩子的结构信息为"││",  * @param junction 结点图标，如果是该结点是它父亲的最后一个结点，  *  则为"└",否则为"├".  */  public void showTree(File root, String childLeftStr, String junction){  //打印结点的信息  System.out.println(junction + root.getName());  //如果有孩子， 而且孩子的数目不为0  if(!root.isFile()&&root.listFiles().length!=0){   File[] files = root.listFiles();   //构造孩子结点   Tree[] children = new Tree[files.length];   for(int i=0; i<files.length; i++){    children[i] = new Tree(files[i]);   }   //打印孩子结点   for(int i=0; i<children.length-1; i++){    //对所有的孩子结点，先打印出左边的结构信息，    System.out.print(childLeftStr);    //递归调用showTree， 注意参数有所变化，文件加的深度增加的时候，它的孩子的结构信息也会    //增加，如果不是最后一个孩子，则结构信息需加上"│"。    showTree(children[i].root,childLeftStr+"│", "├");   }   //最后一个孩子需要特殊处理   //打印结构信息   System.out.print(childLeftStr);   //如果是最后一个孩子，则结构信息需加上" "。   //结点形状也调整为"└"   showTree(children[files.length-1].root, childLeftStr+" ","└");  } } public static void main(String[] args) {  File f = new File("C://test");  Tree t = new Tree(f);  t.showTree(f,"", ""); }}