Java 分组数据结构组装

{
  "code": 0,
  "error": "",
  "trace": "",
  "result": [
    {
      "groupId": 4,
      "groutName": "新增分组测试",
      "children": [
        {
          "id": 7,
          "name": "新增静态Api(更新)"
        }
      ]
    },
    {
      "groupId": 5,
      "groutName": "新增分组测试1",
      "children": [
        {
          "id": 8,
          "name": "新增静态Api-1"
        }
      ]
    }
  ],
  "successful": true
}

public class ApiDTO {

    /**
     * Api树形结构对象
     */
    @Getter
    @Setter
    public static class ApiTree implements Serializable {

        @ApiModelProperty(value = "分组Id", example = "")
        private Integer groupId;

        @ApiModelProperty(value = "分组名称", example = "")
        private String groutName;

        @ApiModelProperty(value = "所有Api")
        private List<ApiBase> children;
    }

    /**
     * 分类树形结构对象
     */
    @Getter
    @Setter
    public static class ApiBase implements Serializable {

        @ApiModelProperty(value = "apiId", example = "")
        private Integer id;

        @ApiModelProperty(value = "api 名称", example = "")
        private String name;
    }

}

//获取所有的数据
List<ApiBaseGroupDTO> groupDTOList = apiBaseMapper.getAllApiGroupByName(param.getApiName());
//按GroupId分组
Map<Integer, List<ApiBaseGroupDTO>> groupMap = groupDTOList.stream().collect(Collectors.groupingBy(it -> it.getGroupId()));

//转前端需要的树结构对象
List<ApiDTO.ApiTree> treeList = groupDTOList.stream().map(it -> {
    ApiDTO.ApiTree apiTree = new ApiDTO.ApiTree();
    apiTree.setGroupId(it.getGroupId());
    apiTree.setGroutName(it.getGroutName());
    return apiTree;
}).collect(Collectors.toList());

//每个节点添加上子节点
treeList.forEach(it -> {
    List<ApiDTO.ApiBase> apiList = groupMap.get(it.getGroupId()).stream().map(api -> {
        ApiDTO.ApiBase apiBase = new ApiDTO.ApiBase();
        apiBase.setId(api.getId());
        apiBase.setName(api.getName());
        return apiBase;
    }).collect(Collectors.toList());
    it.setChildren(apiList);
});