feat: 查询通用 tree util

cadecode · cadecode · commit 2f7585bbfaf2 · 2023-11-26T16:56:24.000+08:00
diff --git a/common/core/src/main/java/com/github/cadecode/uniboot/common/core/util/TreeUtil.java b/common/core/src/main/java/com/github/cadecode/uniboot/common/core/util/TreeUtil.java
@@ -0,0 +1,47 @@
+package com.github.cadecode.uniboot.common.core.util;
+
+import cn.hutool.core.util.ObjUtil;
+
+import java.util.List;
+import java.util.function.BiConsumer;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+/**
+ * Tree 工具
+ *
+ * @author Cade Li
+ * @since 2023/11/26
+ */
+public class TreeUtil {
+
+    /**
+     * List 树形化
+     *
+     * @param list 原数据列表
+     * @param rootId root id
+     * @param idGetter 获取 id 的方法
+     * @param parentIdGetter 获取 parentId 的方法
+     * @param childrenSetter 设置 children 的方法
+     * @return 树形化之后的列表
+     * @param <T> 原数据类型
+     * @param <L> 数据 ID 类型
+     */
+    public static <T, L> List<T> listToTree(List<T> list,
+                                            L rootId,
+                                            Function<T, L> idGetter,
+                                            Function<T, L> parentIdGetter,
+                                            BiConsumer<T, List<T>> childrenSetter) {
+        List<T> parentList = list.stream()
+                .filter(o -> ObjUtil.equals(rootId, parentIdGetter.apply(o)))
+                .collect(Collectors.toList());
+        parentList.forEach(p -> {
+            List<T> children = list.stream()
+                    .filter(c -> ObjUtil.equals(parentIdGetter.apply(c), idGetter.apply(p)))
+                    .peek(c -> childrenSetter.accept(c, listToTree(list, idGetter.apply(c), idGetter, parentIdGetter, childrenSetter)))
+                    .collect(Collectors.toList());
+            childrenSetter.accept(p, children);
+        });
+        return parentList;
+    }
+}
