一次性搞定權(quán)限樹遍歷（通用解決方案）
data：數(shù)據(jù)庫表的任意一行權(quán)限 childrenNode：data節(jié)點下所有的權(quán)限集合
public class TreeNode<T> {//數(shù)據(jù)內(nèi)容private T data;//這個節(jié)點下的子節(jié)點private List<TreeNode<T>> childrenNode = new ArrayList<>();public T getData() {return data;}public void setData(T data) {this.data = data;}public List<TreeNode<T>> getChildrenNode() {return childrenNode;}public void setChildrenNode(List<TreeNode<T>> childrenNode) {this.childrenNode = childrenNode;}public TreeNode(T data, List<TreeNode<T>> childrenNode) {this.data = data;this.childrenNode = childrenNode;}public TreeNode() {}}
public List<TreeNode<T>> childrenNode(List<T> datas, String idName, String fidName) {ConvertTree<T> convertTree = new ConvertTree<>();String idValue = convertTree.getFieldValue(data, idName);List<T> collect = datas.stream().filter(date -> idValue.equals(convertTree.getFieldValue(date, fidName))).collect(Collectors.toList());datas.removeAll(collect);for (T node : collect) {TreeNode<T> treeNode = new TreeNode<>();treeNode.setData(node);childrenNode.add(treeNode);}return childrenNode;}
public String getFieldValue(T o, String fieldName) {//得到classClass cls = o.getClass();//得到所有屬性Field[] fields = cls.getDeclaredFields();for (Field field : fields) {try {//打開私有訪問field.setAccessible(true);//獲取屬性if (field.getName().equals(fieldName)) {Object result = field.get(o);if (result == null) {return null;}return result.toString();}} catch (IllegalAccessException e) {e.printStackTrace();}}throw new RuntimeException("獲取屬性值失敗");}
private TreeNode<T> getRootNode(List<T> datas, String idName, String fidName) {if (datas.isEmpty()) {return null;}T node = datas.get(0);T rootNode = getRootNode(datas, idName, fidName, node);TreeNode<T> rootTreeNode = new TreeNode<>();datas.remove(rootNode);rootTreeNode.setData(rootNode);rootTreeNode.childrenNode(datas, idName, fidName);return rootTreeNode;}
private T getRootNode(List<T> datas, String idName, String fidName, T node) {T fNode = null;String fieldValue = getFieldValue(node, fidName);for (T data : datas) {if (getFieldValue(data, idName).equals(fieldValue)) {fNode = data;break;}}if (fNode == null) {return node;} else {return getRootNode(datas, idName, fidName, fNode);}}
private TreeNode<T> getTree(List<T> datas, String idName, String fidName) {//獲取樹根TreeNode<T> rootNode = getRootNode(datas, idName, fidName);//遍歷樹根的子集List<TreeNode<T>> childrenNode = rootNode.getChildrenNode();forChildren(datas, idName, fidName, childrenNode);//此時樹已經(jīng)形成return rootNode;}
private void forChildren(List<T> datas, String idName, String fidName, List<TreeNode<T>> childrenNode) {//需要遍歷的集合List<TreeNode<T>> needForList = new ArrayList<>();for (TreeNode<T> tTreeNode : childrenNode) {List<TreeNode<T>> treeNodes = tTreeNode.childrenNode(datas, idName, fidName);needForList.addAll(treeNodes);}if (!needForList.isEmpty()) {forChildren(datas, idName, fidName, needForList);}}
public List<TreeNode<T>> getForest(List<T> datas, String idName, String fidName) {List<TreeNode<T>> forest = new ArrayList<>();while (!datas.isEmpty()) {TreeNode<T> tree = getTree(datas, idName, fidName);forest.add(tree);}return forest;}
public List<TreeNode<AuthResource>> toTree() {//獲取數(shù)據(jù)集合List<AuthResource> list = authResourceRepository.findAll();//創(chuàng)建工具類ConvertTree<AuthResource> convertTree = new ConvertTree<>();//生成森林List<TreeNode<AuthResource>> forest = convertTree.getForest(list, "id", "parentId");return convertTree.getForest(list);}
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