Java data encapsulation tree structure code example

This article mainly introduces the Java data encapsulation tree structure code example. The example code is introduced in great detail, which has a certain reference value for everyone's study or work. Friends in need can refer to it

1. Entity class

@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. Data encapsulation

@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,map);
               childList.add(c);
             });

    parent.setChildren(childList);
  }

3. Results

{
 "code": 20000,"message": "成功","data": [
  {
   "code": null,"createtime": null,"defaultmanual": null,"description": null,"id": "dc1d70b9eb7b4df3bbe8dcc6a93cbd57","isdelete": -1,"lastmodifytime": null,"name": "基础服务","parentid": "","sort": 1,"children": [
    {
     "code": null,"id": "b1779671ef1b45e0a9a8a1edbff03f1e","name": "数据源服务","parentid": "dc1d70b9eb7b4df3bbe8dcc6a93cbd57","sort": 2,"children": [
      {
       "code": null,"id": "2a38a8254ec348e9b54c9bf4622f23db","isdelete": 1,"name": "测试添加数据库服务2","parentid": "b1779671ef1b45e0a9a8a1edbff03f1e","sort": null,"children": []
      }
     ]
    },{
     "code": null,"id": "d4f3b047dc2d467a9b404ded8acf4673","name": "text_lsa","children": []
    }
   ]
  },{
   "code": null,"id": "af1b4a4d2f074fa19e1dae0a5540a5bf","name": "测试添加1","children": []
  },"id": "62e15d859a224126884888a55df355a7","name": "测试添加2","children": []
  }
 ]
}

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