/**
 * 樹形數(shù)據(jù)實(shí)體接口 
 * @author YangWenHui
 * @date 2018年4月11
 * @param <T>
 */
public interface dataTree<T> {
	
    public String getId();
	
  public String getParentId();
  
  public void setChildList(List<T> childList);
  
  public List<T> getChildList();
}

/**
 * 獲取樹型工具類
 * @author YangWenHui
 *
 */
public class TreeUtil {
	
	//獲取頂層節(jié)點(diǎn)
	public static <T extends dataTree<T>> List<T> getTreeList(String topId,List<T> entityList){
		List<T> resultList = new ArrayList<>();//存儲頂層的數(shù)據(jù)
		
		Map<Object, T> treeMap = new HashMap<>();
		T itemTree;
		
		for(int i=0;i<entityList.size()&&!entityList.isEmpty();i++) {
			itemTree = entityList.get(i);
			treeMap.put(itemTree.getId(),itemTree);//把所有的數(shù)據(jù)放到map當(dāng)中，id為key
			if(topId.equals(itemTree.getParentId()) || itemTree.getParentId() == null) {//把頂層數(shù)據(jù)放到集合中
				resultList.add(itemTree);
			}
		}
		
		//循環(huán)數(shù)據(jù)，把數(shù)據(jù)放到上一級的childen屬性中
		for(int i = 0; i< entityList.size()&&!entityList.isEmpty();i++) {
			itemTree = entityList.get(i);
			T data = treeMap.get(itemTree.getParentId());//在map集合中尋找父親
			if(data != null) {//判斷父親有沒有
				if(data.getChildList() == null) {
					data.setChildList(new ArrayList<>());
				}
				data.getChildList().add(itemTree);//把子節(jié)點(diǎn) 放到父節(jié)點(diǎn)childList當(dāng)中
				treeMap.put(itemTree.getParentId(), data);//把放好的數(shù)據(jù)放回map當(dāng)中
			}
		}
		return resultList;
	}
}

/**
 * 生成樹數(shù)據(jù)的接收類
 * @author YangWenHui
 *
 */
@Data
public class OtlDeptMenu implements dataTree<OtlDeptMenu>{
	
	
	private String id;
	
	private String parentId;
	
	private String name;
	
	private List<OtlDeptMenu> childList;
}

	/**
	 * 根據(jù)數(shù)據(jù)返回樹型結(jié)構(gòu)
	 * @return
	 */
	public List<OtlDeptMenu> getparticipants(){
		List<OtlDeptMenu> data = otlMeetPeopleMapper.getDeptName();//接收在數(shù)據(jù)庫中查詢到的數(shù)據(jù)
		List<OtlDeptMenu> list = new ArrayList<>();//返回的最終集合，可根據(jù)自己返回類型更改。
		List<OtlDeptMenu> tree = TreeUtil.getTreeList("0", data);//調(diào)用工具類，第一個(gè)參數(shù)是默認(rèn)傳入的頂級id，和查詢出來的數(shù)據(jù)
		OtlDeptMenu result = new OtlDeptMenu();//我在已經(jīng)生成好的樹形結(jié)構(gòu)外面有包了一層。視情況而定，可以不用寫
		result.setId("0");
		result.setName("請選擇參與部門");
		result.setChildList(tree);
		list.add(result);//把對象放到list中，前臺element-ui中的樹形控件需要的是數(shù)組的集合
		return list;
	}