樹結構在開發中經常遇到。例如：部門、菜單、員工架構等等。下面用部門作為例子構造部門結構樹

1、部門表：dept

-- ----------------------------
-- Table structure for dept
-- ----------------------------
DROP TABLE IF EXISTS `dept`;
CREATE TABLE `dept` (
  `id` varchar(36) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  `parent_id` varchar(36) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2、實體類：Dept

public class Dept implements Serializable {
    private static final long serialVersionUID = -2809004220612317111L;
    //ID
    private String id;
    //部門名稱
    private String name;
    //父ID
    private String parentId;
    
     //get/set方法省略
}

JAVA代碼實現多級樹結構封裝對象