jdk8 三行代碼實現數據遞歸

菜單對象

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.zcckj.common.model.dto.BaseDTO;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.experimental.Accessors;

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotBlank;
import java.util.List;

/**
 * @author fsren
 * @date 2019-09-10
 */
@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@ApiModel
public class DistributorMenuDTO extends BaseDTO {

    /**
     * 菜單名稱
     */
    @NotBlank(groups = {Save.class}, message = "菜單名稱不可爲空")
    @ApiModelProperty(value = "菜單名稱")
    private String name;

    /**
     * 菜單URL
     */
    @ApiModelProperty(value = "菜單URL")
    private String url;

    /**
     * 授權(多個用逗號分隔，如：user:list,user:create)
     */
    @ApiModelProperty(value = "授權(多個用逗號分隔，如：user:list,user:create)")
    private String authorities;

    /**
     * 類型(0:目錄   1:菜單   2:按鈕)
     */
    @Min(groups = {Save.class}, value = 0, message = "0:目錄 1:菜單 2:按鈕")
    @Max(groups = {Save.class}, value = 2, message = "0:目錄 1:菜單 2:按鈕")
    @ApiModelProperty(value = "類型(0:目錄   1:菜單   2:按鈕)")
    private Integer type;

    /**
     * 描述
     */
    @ApiModelProperty(value = "描述")
    private String description;

    /**
     * 父級ID
     */
    @Min(groups = {Save.class}, value = 0, message = "父級ID應爲正整數")
    @ApiModelProperty(value = "父級ID")
    private Long parentId;

    /**
     * 排序
     */
    @ApiModelProperty(value = "排序")
    @Min(groups = {Save.class}, value = 0, message = "排序值應大於0")
    private Integer sort;

    /**
     * 賬號是否刪除
     */
    @JsonIgnore
    @ApiModelProperty(value = "是否刪除")
    private Boolean isDelete;

    /**
     * @author l'amour solitaire
     * @description 是否有權限(查詢)
     * @date 2019/10/16 下午5:04
     */
    @ApiModelProperty(value = "是否有權限")
    private Boolean haveJurisdiction;

    /**
     * 子項
     */
    @ApiModelProperty(value = "子項")
    private List<DistributorMenuDTO> children;

    public interface Search {
    }

}

遞歸

    /**
     * @author l'amour solitaire
     * @description 遞歸菜單
     * @date 2020/3/24 下午3:12
     */
    private static List<DistributorMenuDTO> makeTree(List<DistributorMenuDTO> distributorMenuList, Long pId) {
        List<DistributorMenuDTO> children = distributorMenuList.stream().filter(x -> x.getParentId().equals(pId)).collect(Collectors.toList());
        List<DistributorMenuDTO> successor = distributorMenuList.stream().filter(x -> !x.getParentId().equals(pId)).collect(Collectors.toList());
        children.forEach(x -> x.setChildren(makeTree(successor, x.getId())));
        return children;
    }