java string转list对象(java set转list)

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package com.jianshu.utils;

import lombok.Data;
import lombok.extern.slf4j.Slf4j;

import java.util.List;
import java.util.stream.Collectors;


@Slf4j
public class TreeUtil {

    
    public static  List listToTree(List list, Long rootParentId) {
        return list.stream()
                .filter(treeNodeDTO -> treeNodeDTO.getParentId().equals(rootParentId))
                .peek(treeNodeDTO -> treeNodeDTO.setChildrenList(listToTree(list, treeNodeDTO.getId())))
                .collect(Collectors.toList());
    }

    
    @Data
    public static class TreeNodeDTO {

        
        private Long id;

        
        private Long parentId;

        
        private List childrenList;
    }
}

使用方式

定义一个结果Model类

package com.jianshu.vo;

import com.jianshu.TreeUtil;
import lombok.Data;
import lombok.EqualsAndHashCode;


@Data
@EqualsAndHashCode(callSuper = true)
public class DemoTreeNode extends TreeUtil.TreeNodeDTO {

    
    private String column1;

    
    private String column2;
    
    // ...
}

调用代码

// 准备list数据
List list; 
// 计算tree数据
TreeUtil.listToTree(list, 0L);