树形结构工具类

喜欢ヅ旅行 2023-01-17 04:59 108阅读 0赞

import com.zbwd.outline.entity.SysDepartment;
    import org.springframework.util.CollectionUtils;
    import org.springframework.util.ObjectUtils;
    
    import java.util.ArrayList;
    import java.util.List;
    import java.util.stream.Collectors;
    
    /**
     @Description: 树形工具类
     @author yzd
     @create 2021-04-27 9:04
     **/
    public class TreeUtil {
        
        /**
         * 单位树构建 减小复杂度
         *
         * @param childList 子集
         * @param orgRoot 根节点
         */
        public static void makeTree(List<SysDepartment> childList, SysDepartment orgRoot) {
        
            //子类
            List<SysDepartment> children = childList.stream()
                    .filter(x -> (!ObjectUtils.isEmpty(x.getParentId())
                            && x.getParentId().equals(orgRoot.getId()))
                    ).collect(Collectors.toList());
    
            if (!CollectionUtils.isEmpty(children)) {
        
                orgRoot.setChildren(children);
            }
    
            //后辈中的非子类
            List<SysDepartment> successor = childList
                    .stream().filter(x -> !ObjectUtils.isEmpty(x.getParentId())
                            && !x.getParentId().equals(orgRoot.getId()))
                    .collect(Collectors.toList());
    
            if (!CollectionUtils.isEmpty(successor)) {
        
                children.forEach(x ->
                        makeTree(childList, x)
                );
            }
        }
    
        /**
         * 单位树处理  循环处理 替换递归
         *
         * @param treeList
         * @param orgRoot
         * @return
         */
        private List<SysDepartment> childList(List<SysDepartment> treeList, SysDepartment orgRoot) {
        
    
            for (SysDepartment outer : treeList) {
        
                Long outerId = outer.getId();
                List<SysDepartment> childList = new ArrayList<>(treeList.size());
                for (SysDepartment inner : treeList) {
        
                    Long parentId = inner.getParentId();
                    if (!ObjectUtils.isEmpty(parentId) && parentId.equals(outerId)) {
        
                        childList.add(inner);
                    }
                }
                outer.setChildren(childList);
            }
            // 根节点
            return treeList.stream()
                    .filter(item -> item.getId().equals(orgRoot.getId()))
                    .collect(Collectors.toList());
        }
    
        /**
         * 求子集
         *
         * @param allOrgList   所有的组织信息
         * @param childList    孩子信息 即 返回体
         * @param rootId 父节点唯一标识
         */
        public static void makeChild(List<SysDepartment> allOrgList, List<SysDepartment> childList, Long rootId) {
        
            //子类
            List<SysDepartment> children = allOrgList.stream()
                    .filter(x -> (!ObjectUtils.isEmpty(x.getParentId())
                            && rootId.equals(x.getParentId()))
                    ).collect(Collectors.toList());
    
            if (!CollectionUtils.isEmpty(children)) {
        
                childList.addAll(children);
            }
            //后辈中的非子类
            List<SysDepartment> successor = allOrgList
                    .stream().filter(x -> !ObjectUtils.isEmpty(x.getParentId())
                            && !rootId.equals(x.getParentId()))
                    .collect(Collectors.toList());
    
            if (!CollectionUtils.isEmpty(successor) && !CollectionUtils.isEmpty(children)) {
        
    
                List<Long> childIdList = children.stream()
                        .map(SysDepartment::getId)
                        .distinct()
                        .collect(Collectors.toList());
    
                for (Long childId : childIdList) {
        
                    makeChild(successor, childList, childId);
                }
            }
        }
    }