Java: 返回樹形結構數據

Java - 返回樹形結構數據

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1.TreeNodeDto

@Data
public class TreeNodeDto {

    private Long id;

    private Long organizationId;

    private Long parentOrgId;

    private Integer level;

    private Integer sort;

    private String path;

    private String code;

    private String name;

    private String note;

    private List children = new ArrayList();
}

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2.TreeUtil

/**
 * 返回樹形結構數據
 *
 * @author dijk
 */
public class TreeUtil {

    public static List<TreeNodeDto> formatter(List<TreeNodeDto> list) {
        //定義map集合封裝參數
        Map<Long, TreeNodeDto> map = new HashMap<>(50);
        for (TreeNodeDto treeNode : list) {
            //遍歷list將結點id封裝進map中
            map.put(treeNode.getOrganizationId(), treeNode);
        }

        //設置父子級關係
        return addChildren(list, map);
    }

    private static List<TreeNodeDto> addChildren(List<TreeNodeDto> list, Map<Long, TreeNodeDto> map) {
        List<TreeNodeDto> rootNodes = new ArrayList<>();
        for (TreeNodeDto treeNode : list) {
            TreeNodeDto parentNode = map.get(treeNode.getParentOrgId());
            if (parentNode != null) {
                //存在父級結點
                parentNode.getChildren().add(treeNode);
            } else {
                //沒有父級節點，即本身爲根結點
                rootNodes.add(treeNode);
            }
        }
        return rootNodes;
    }
}