java web 后台树形菜单排序

1.需求场景

数据库后台返回树形结构菜单，实现菜单排序。

2.项目环境

spring spring mvc mybatis  mysql

3.实现方法

对应的实体类

private int id;// '主键ID',
private String cname;// '菜单名称',
private int pid;// '父级ID',默认0
private String redirect;// '菜单地址',
private String creator;// '创建者',
private String updatedate;// '修改日期',
private String updator;// '修改者',
private String createdate;// '创建日期',
private double sortid;//菜单排序字段 默认0
private List<AuthUser> children;//父菜单下的子菜单

封装树形数据

public class TreeUtil {
    private  int count = 0;
    private List<AuthUser> nodes;  
      
    public TreeUtil(List<AuthUser> nodes){  
        this.nodes = nodes;  
    }  
      
    public List<AuthUser> buildTree(){  
    	List<AuthUser> list = new ArrayList<AuthUser>();
    	for (AuthUser node : nodes) {   
            if (node.getPid() == 0) {  
              list.add(node);
            }  
        }  
        list = getSortChildren(list);
        for (AuthUser node : list) {
    	   build(node); 
	     }
        return list;
    }  
    
    /***
     * 构建权限树
    * @Title: build 
    * @Description: TODO
    * @param node
     */
    private void build(AuthUser node){  
        List<AuthUser> children = getChildren(node);  
        if (!children.isEmpty()) {  
        	  node.setChildren(children);
        	  if(count <3){
          		//children.get(0).setChecked("true");//设置默认选中
   			   count ++;
   			   }
            for (AuthUser child : children) {  
                build(child);  
            }  
        } 
    }  
    /**
     * 
    * @Title: getChildren 
    * @Description: TODO 获取子节点
    * @param node
    * @return
     */
    private List<AuthUser> getChildren(AuthUser node){  
        List<AuthUser> children = new ArrayList<AuthUser>();  
        Integer id = node.getId();  
        for (AuthUser child : nodes) {  
            if (id==child.getPid()) {  
                children.add(child);  
            }  
        }  
        return getSortChildren(children);
       // return children;  
    }  
    
    /**
     * 
    * @Title: getChildren 
    * @Description: TODO 获取排序子节点
    * @param node
    * @return
     */
    private List<AuthUser> getSortChildren(List<AuthUser> children){
    	MyCompare my = new MyCompare();
    	Collections.sort(children,my) ; 
        return children;  
    }  
}

自定义比较器

    public class MyCompare implements Comparator<AuthUser>{

	@Override
	public int compare(AuthUser o1, AuthUser o2) {
		 if(o1.getSortid()<o2.getSortid()){
			 return -1;
		 }else{
			 return 1;
		 }
	}
}

数据库返回

	public void getauthinfo(Map<String,object> param){
		    List<AuthUser> authList =userRoleService.getUserAuthTree(param); //执行查询
			  TreeUtil tree = new TreeUtil(authList);  
			  //返回按照sortid排好序的树形结构的菜单
		    List<AuthUser> datalist = tree.buildTree();  
			}
		} catch (Exception e) {
			e.printStackTrace();
		 
		}
	}