package testSimple;

 import java.util.ArrayList;

 import java.util.List;

 public class BuildTree {

     public static void main(String[] args) {

         List<Tree> list = new ArrayList<Tree>();

         list.add(new Tree(1, "一级菜单", 0));

         list.add(new Tree(2, "二级菜单1", 1));

         list.add(new Tree(3, "二级菜单2", 1));

         list.add(new Tree(4, "二级菜单3", 1));

         list.add(new Tree(5, "三级菜单11", 2));

         list.add(new Tree(6, "三级菜单12", 2));

         list.add(new Tree(7, "三级菜单21", 3));

         list.add(new Tree(8, "三级菜单22", 3));

         list.add(new Tree(9, "三级菜单31", 4));

         list.add(new Tree(10, "三级菜单32", 4));

         List<Tree> result = buildTree(list, 0);

         System.out.println(result);

     }

     public static List<Tree> buildTree(List<Tree> list, int fid) {

         List<Tree> resultList = new ArrayList<Tree>();

         if (list == null || list.size() == 0 || fid < 0) {

             return null;

         }

         for (Tree tree : list) {

             if (tree.getFid() == fid) {

                 resultList.add(tree);

                 tree.setChildren(buildTree(list, tree.getId()));

             }

         }

         return resultList;

     }

 }

 class Tree {

     private int id;

     private String name;

     private int fid;

     private List<Tree> children;

     public Tree(int id, String name, int fid) {

         super();

         this.id = id;

         this.name = name;

         this.fid = fid;

     }

     public int getId() {

         return id;

     }

     public void setId(int id) {

         this.id = id;

     }

     public String getName() {

         return name;

     }

     public void setName(String name) {

         this.name = name;

     }

     public int getFid() {

         return fid;

     }

     public void setFid(int fid) {

         this.fid = fid;

     }

     public List<Tree> getChildren() {

         return children;

     }

     public void setChildren(List<Tree> children) {

         this.children = children;

     }

 }