Hutool工具-TreeUtil使用，教你如何快速构造返回树形结构

项目中经常会遇到各种需要以树形结构展示的功能，如菜单树、分类树、部门树，Hutool的TreeUtil主要是用来快速构造树形结构，以及获取所有叶子节点等操作。

步骤：

1️⃣ 引入hutool最新pom包。
2️⃣ 获取构造树的分类数据。
3️⃣ TreeNodeConfig信息配置，配置节点名称、孩子节点key信息、排序等等。
4️⃣ 调用TreeUtil.build()构造树。

pom依赖

<!-- https://mvnrepository.com/artifact/cn.hutool/hutool-all -->
<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.7.22</version>
</dependency>

资料分类Service接口层

/**
 * 构造班型资料分类树方法
 *
 * @author: jacklin
 * @date: 2022/4/20 16:44
 **/
List<Tree<String>> constructTree();

实现层

@Override
public List<Tree<String>> constructTree() {
    //1.获取所有资料分类
    List<SdSchoolClassTypeDataCategory> dataList = this.lambdaQuery().getBaseMapper().selectList(Wrappers.lambdaQuery(SdSchoolClassTypeDataCategory.class)
            .eq(SdSchoolClassTypeDataCategory::getStatus, SchoolConstant.ENABLE_STATUS)
            .eq(SdSchoolClassTypeDataCategory::getDeleted, SchoolConstant.DELETE_STATUS_NORMAL));

    //2.配置
    TreeNodeConfig config = new TreeNodeConfig();
    config.setIdKey("id");                              //默认id，可以不设置
    config.setParentIdKey("pid");                       //父id
    config.setNameKey("dataCategoryName");              //分类名称
    config.setDeep(3);                                  //最大递归深度
    config.setChildrenKey("childrenList");              //孩子节点
    config.setWeightKey("sort");                        //排序字段

    //3.转树
    List<Tree<String>> treeList = TreeUtil.build(dataList, "0", config, ((object, treeNode) -> {
        treeNode.putExtra("id", object.getId());
        treeNode.putExtra("pid", object.getPid());
        treeNode.putExtra("dataCategoryName", object.getDataCategoryName());
        treeNode.putExtra("level", object.getLevel());
        treeNode.putExtra("sort", object.getSort());
        //扩展属性...
    }));

    return treeList;
}

😀通过TreeNodeConfig我们可以自定义节点的名称、关系节点id名称，这样就可以和不同的数据库做对应。

controller

/**
 * 获取构造树
 *
 * @author: jacklin
 * @date: 2022/4/20 17:18
 **/
@ApiOperation(value = "获取构造树", notes = "获取构造树")
@GetMapping(value = "/getConstructTree")
public Result<?> getConstructTree() {
    List<Tree<String>> treeList = sdSchoolClassTypeDataCategoryService.constructTree();
    return Result.OK(treeList);
}

响应内容

{
    "success":true,
    "message":"操作成功！",
    "code":200,
    "result":[
         {
            "id":"1447031605584797698",
            "pid":"0",
            "dataCategoryName":"开发测试资料一级分类",
            "level":1,
            "sort":1,
            "childrenList":[
                {
                    "id":"1447031722601684993",
                    "pid":"1447031605584797698",
                    "dataCategoryName":"开发测试资料二级分类",
                    "level":2,
                    "sort":1,
                    "childrenList":[
                        {
                            "id":"1516684508672299010",
                            "pid":"1447031722601684993",
                            "dataCategoryName":"开发测试资料三级分类",
                            "level":3,
                            "sort":1
                        }
                    ]
                }
            ]
        },
        {
            "id":"1447849327826636801",
            "pid":"0",
            "dataCategoryName":"测试资料分类",
            "level":1,
            "sort":1,
            "childrenList":[
                {
                    "id":"1447849471787732993",
                    "pid":"1447849327826636801",
                    "dataCategoryName":"测试资料分类2-1",
                    "level":2,
                    "sort":1
                },
                {
                    "id":"1447849472085528577",
                    "pid":"1447849327826636801",
                    "dataCategoryName":"测试资料分类2-2",
                    "level":2,
                    "sort":1
                },
                {
                    "id":"1447849472219746305",
                    "pid":"1447849327826636801",
                    "dataCategoryName":"测试资料分类2-3",
                    "level":2,
                    "sort":1
                }
            ]
        }
    ]
}

更多了解可以参考Hutool官方说明：www.hutool.cn/docs/#/core…