public class MyTree {
    private String id;
    private String parentId;
    private String name;
    private List<MyTree> child = Lists.newArrayList();
    //getter()、setter()方法。。。public void addChild(MyTree tree){
        child.add(tree);
    }

//获取数据
List<MyTree> treeList=initList();
MyTree resultTree=null;
//添加父节点和子节点依赖关系　　　　　
for(MyTree outTree:treeList){
   String id=outTree.getId();
　　//找到根节点
   if("0".equals(outTree.getParentId())){
      resultTree=outTree;
   }
   for(MyTree innerTree:treeList){
      String parentId=innerTree.getParentId();
      if(id.equals(parentId)){
         outTree.addChild(innerTree);
      }
   }
}