用JAVA实现文本形式的树状结构显示

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(" ");




if (children.size() > 0) ...{




for (int i = 0; i < children.size() - 1; i++) ...{


b.append(lftStr + ((Folder) children.get(i)).toString(lftStr + "│", "├"));


}


b.append(lftStr + ((Folder) 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);


Folder f2 = new Folder("My Documents ");


root.addChild(f2);


Folder f3 = new Folder("My Documents2 ");


root.addChild(f3);


System.out.println(root.toString(" ", ""));


}


}