1. 引入依赖

<dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>${hutool.version}</version>
</dependency>

2. 测试

@SpringBootTest
public class HutoolTest {private List<Menu> menuList = new ArrayList<>();@BeforeEachpublic void init() {menuList.add(new Menu(1L, 0L, "一级菜单", 1, "first", LocalDateTime.now()));menuList.add(new Menu(2L, 1L, "二级菜单", 1, "second", LocalDateTime.now()));menuList.add(new Menu(3L, 2L, "三级菜单", 1, "first", LocalDateTime.now()));menuList.add(new Menu(4L, 0L, "一级菜单-1", 2, "first-1", LocalDateTime.now()));}/*** weight越小越靠上*/@Testpublic void testBuildTree() {TreeNodeConfig config = new TreeNodeConfig();config.setIdKey("id");config.setParentIdKey("pid");config.setChildrenKey("children");config.setNameKey("name");config.setWeightKey("weight");List<Tree<Long>> treeList = TreeUtil.build(menuList, 0L, config, new NodeParser<Menu, Long>() {@Overridepublic void parse(Menu menu, Tree<Long> tree) {tree.setId(menu.id);tree.setParentId(menu.pid);tree.setName(menu.name);tree.setWeight(menu.weight);Map<String, Object> map = new HashMap();map.put("code", menu.code);map.put("createTime", menu.createTime);tree.putAll(map);}});System.out.println(JSONUtil.toJsonStr(treeList));}class Menu {private Long id;private Long pid;private String name;private Integer weight;private String code;private LocalDateTime createTime;public Menu(Long id, Long pid, String name, Integer weight, String code, LocalDateTime createTime) {this.id = id;this.pid = pid;this.name = name;this.weight = weight;this.code = code;this.createTime = createTime;}}
}

3. 结果

[{"id": 1,"pid": 0,"name": "一级菜单","code": "first","createTime": "first","children": [{"id": 2,"pid": 1,"name": "二级菜单","code": "second","createTime": "second","children": [{"id": 3,"pid": 2,"name": "三级菜单","code": "first","createTime": "first"}]}]},{"id": 4,"pid": 0,"name": "一级菜单-1","code": "first-1","createTime": "first-1"}
]