这篇文章主要介绍了Java数据封装树形结构代码实例,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

1、实体类

@data
public class PublishServiceType implements Comparable<PublishServiceType>{


  /**
   * 
   */
  private static final long serialVersionUID = -3572108154932898825L;


  /* 
   * @see [code]
   * @comment 类型标识
   */
  private String code;
  /* 
   * @see {createtime}
   * @comment 创建时间
   */
  private java.util.Date createtime;
  /* 
   * @see {defaultmanual}
   * @comment 服务类型默认使用手册
   */
  private String defaultmanual;
  /* 
   * @see {description}
   * @comment 服务类型描述
   */
  private String description;
  /* 
   * @see {id}
   * @comment 主键
   */
  private String id;
  /* 
   * @see {isdelete}
   * @comment 是否可以删除
   */
  private Integer isdelete;
  /* 
   * @see {lastmodifytime}
   * @comment 最近修改时间
   */
  private java.util.Date lastmodifytime;
  /* 
   * @see {name}
   * @comment 服务类型名称
   */
  private String name;
  /* 
   * @see {parentid}
   * @comment 服务类型父节点
   */
  private String parentid;

  /**
   * 排序
   */
  private Integer sort;

  private List<PublishServiceType>children;
}

2、数据封装

@Override
  public List<PublishServiceType> findList(String name) {
    List<PublishServiceType>list = publishServiceTypeMapper.findByName(name);
    if (JudgeUtil.isEmpty(list)){
      return null;
    }
    //父子级组装
    return parentAndChildren(list);
  }
 private List<PublishServiceType>parentAndChildren(List<PublishServiceType> list){

    //最顶层根节点
    List<PublishServiceType>rootList = new ArrayList<>();
    //非最顶层根节点
    List<PublishServiceType>bodyList = new ArrayList<>();
    for (PublishServiceType publishServiceType : list) {
      if (StringUtils.isBlank(publishServiceType.getParentid())){
        rootList.add(publishServiceType);
      }else{
        bodyList.add(publishServiceType);
      }
    }
    return getTree(rootList,bodyList);
  }

  public List<PublishServiceType> getTree(List<PublishServiceType>rootList, List<PublishServiceType>bodyList){
    if (!JudgeUtil.isEmpty(bodyList)){
      //声明一个map，用来过滤已操作过的数据
      Map<String,String> map = new HashMap<>(bodyList.size());
      rootList.forEach(parent->getChild(parent,bodyList,map));
      return rootList;
    }else{
      return rootList;
    }
  }

  private void getChild(PublishServiceType parent,List<PublishServiceType>bodyList, Map<String,String> map){
    List<PublishServiceType>childList = new ArrayList<>();
    bodyList.stream().filter(c->!map.containsKey(c.getId()))
             .filter(c->c.getParentid().equals(parent.getId()))
             .forEach(c->{
               map.put(c.getId(),c.getParentid());
               getChild(c,bodyList,map);
               childList.add(c);
             });
    
    parent.setChildren(childList);
  }