如何将任意List<T>转化成指定List<T>树形结构

如何将任意List转化成指定List树形结构

权限表PermissionDTO

/**
 * <pre>
 * 权限表 返回数据模型
 * </pre>
 *
 * @author xx
 * @date 2021-07-07
 */
@Data
@ApiModel(value = "PermissionDto", description = "权限表返回数据模型")
public class PermissionDto{
    @ApiModelProperty(value = "主键")
    @Excel(name="主键",cellType = Excel.ColumnType.STRING)
    private Long id;
    
    @ApiModelProperty(value = "描述")
    @Excel(name="描述",cellType = Excel.ColumnType.STRING)
    private String remark;
   
    @ApiModelProperty(value = "父ID")
    @Excel(name="父ID",cellType = Excel.ColumnType.STRING)
    private Long parentId;

    @ApiModelProperty(value = "下级权限")
    private List<PermissionDto> children;
}

树TreeDTO

/**
 * @author xx
 */
@ApiModel(value = "TreeDto", description = "树状数据返回数据模型")
public class TreeDto {
    @ApiModelProperty(value = "数据标题")
    private String title;
    @ApiModelProperty(value = "数据key")
    private String key;
    @ApiModelProperty(value = "下级数据")
    private List<TreeDto> children;

    public TreeDto() { }

    public TreeDto(PermissionDto permissionDto) {
        this.key = permissionDto.getId().toString();
        this.title = permissionDto.getName();
        this.children = permissionDto.getChildren().stream().map(TreeDto::new).collect(Collectors.toList());
    }

    public String getKey()
    {
        return key;
    }

    public void setKey(String key)
    {
        this.key = key;
    }

    public String getTitle()
    {
        return title;
    }

    public void setTitle(String title)
    {
        this.title = title;
    }

    public List<TreeDto> getChildren()
    {
        return children;
    }

    public void setChildren(List<TreeDto> children)
    {
        this.children = children;
    }

}

转化代码

    private List<TreeDto> getTreeDtos() {
        /**
         * service层生成的树形数据
         */
        List<PermissionDto> permissionDtoList = permissionService.getTree(null);
        return permissionDtoList.stream().map(TreeDto::new).collect(Collectors.toList());
    }