java处理数据，输出树形结构

╰半夏微凉° 2021-09-02 09:03 424阅读 0赞

## java处理数据，输出树形结构 ##

**mongo数据库表数据结构，如下**

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**java类处理方法**

package com.necibook.resource.model.vo;
    
    import io.swagger.annotations.ApiModelProperty;
    import lombok.Data;
    import org.apache.commons.lang.StringUtils;
    
    import java.util.*;
    
    /**
     * @author lbx
     * @date 2020-08-24
     */
    
    @Data
    public class ResourceExamTypeVo {
    
        /**
         * 唯一标识，每三位表示一级
         */
        private String id;
    
        /**
         * 类型名称
         */
        private String typeName;
    
        /**
         * 上级类型标识
         */
        private String seniorId;
    
        /**
         * 学段标识
         */
        private String stageId;
    
        /**
         * 层级
         */
        private String level;
        /**
         * 排序
         */
        private String displayOrder;
    
    
        @ApiModelProperty(value = "子级集合")
        protected List<ResourceExamTypeVo> subList;
    
        public void add(ResourceExamTypeVo node) {
            if (this.subList == null) {
                this.subList = new ArrayList<>();
            }
            subList.add(node);
        }
    
        public static List<ResourceExamTypeVo> bulid(List<ResourceExamTypeVo> treeNodes, String root) {
            Map<String, ResourceExamTypeVo> allNodes = new HashMap();
            Iterator var3 = treeNodes.iterator();
            while (var3.hasNext()) {
                ResourceExamTypeVo treeNode = (ResourceExamTypeVo) var3.next();
                allNodes.put(treeNode.getId(), treeNode);
            }
    
            Map<String, ResourceExamTypeVo> allRoots = new LinkedHashMap();
            Iterator var8 = treeNodes.iterator();
    
            while (true) {
                ResourceExamTypeVo parentNode;
                while (var8.hasNext()) {
                    ResourceExamTypeVo treeNode = (ResourceExamTypeVo) var8.next();
                    if (StringUtils.isNotBlank(root) && treeNode.getId().equals(root)) {
                        allRoots.put(treeNode.getId(), treeNode);
                    } else if (StringUtils.isBlank(treeNode.getSeniorId())) {
                        allRoots.put(treeNode.getId(), treeNode);
                    } else if (StringUtils.isNotBlank(root) && root.equals(treeNode.getSeniorId()) && !allNodes.containsKey(root)) {
                        allRoots.put(treeNode.getId(), treeNode);
                    } else if (StringUtils.isNotBlank(treeNode.getSeniorId())) {
                        parentNode = (ResourceExamTypeVo) allNodes.get(treeNode.getSeniorId());
                        if (parentNode != null) {
                            if (parentNode.getSubList() == null) {
                                parentNode.setSubList(new ArrayList());
                            }
                            parentNode.add(treeNode);
                        }
                    }
                }
                List<ResourceExamTypeVo> ret = new ArrayList();
                Iterator var10 = allRoots.values().iterator();
                while (var10.hasNext()) {
                    parentNode = (ResourceExamTypeVo) var10.next();
                    ret.add(parentNode);
                }
                return ret;
            }
        }
    
        public static List<ResourceExamTypeVo> bulid(List<ResourceExamTypeVo> treeNodes) {
            return ResourceExamTypeVo.bulid(treeNodes, "0");
        }
    
        public ResourceExamTypeVo() {
    
        }
    }

**serviceImpl,读取数据传入bulid方法**

package com.necibook.resource.service.impl;
    
    
    import com.necibook.resource.model.entity.ResourceExamTypeEntity;
    import com.necibook.resource.model.vo.ResourceExamTypeVo;
    import com.necibook.resource.service.ResourceExamTypeService;
    import ma.glasnost.orika.MapperFacade;
    import org.apache.commons.lang3.StringUtils;
    import org.springframework.data.mongodb.core.MongoTemplate;
    import org.springframework.stereotype.Service;
    
    import javax.annotation.Resource;
    import java.util.List;
    
    @Service
    public class ResourceExamTypeServiceImpl implements ResourceExamTypeService {
        @Resource
        private MongoTemplate mongoTemplate;
        @Resource
        private MapperFacade mapperFacade;
    
        @Override
        public List<ResourceExamTypeVo> baseShoolMajor(String id) {
            List<ResourceExamTypeEntity> resourceExamTypeEntityList = mongoTemplate.findAll(ResourceExamTypeEntity.class);
            List<ResourceExamTypeVo> resourceExamTypeVoList = mapperFacade.mapAsList(resourceExamTypeEntityList, ResourceExamTypeVo.class);
            String root = StringUtils.isNotBlank(id) ? id : "0";
            resourceExamTypeVoList = ResourceExamTypeVo.bulid(resourceExamTypeVoList, root);
            return resourceExamTypeVoList;
        }
    }

返回值数据结构，如下

{
        "code": 0,
        "message": "success",
        "tipMsg": null,
        "result": [
            {
                "id": "01",
                "typeName": "哲学",
                "seniorId": "0",
                "stageId": "3",
                "level": "1",
                "displayOrder": "1",
                "subList": [
                    {
                        "id": "0101",
                        "typeName": "哲学类",
                        "seniorId": "01",
                        "stageId": "3",
                        "level": "2",
                        "displayOrder": "2",
                        "subList": [
                            {
                                "id": "010101",
                                "typeName": "哲学",
                                "seniorId": "0101",
                                "stageId": "3",
                                "level": "3",
                                "displayOrder": "3",
                                "subList": []
                            },
                            {
                                "id": "010102",
                                "typeName": "逻辑学",
                                "seniorId": "0101",
                                "stageId": "3",
                                "level": "3",
                                "displayOrder": "3",
                                "subList": []
                            },
                            {
                                "id": "010103K",
                                "typeName": "宗教学",
                                "seniorId": "0101",
                                "stageId": "3",
                                "level": "3",
                                "displayOrder": "3",
                                "subList": []
                            },
                            {
                                "id": "010104T",
                                "typeName": "伦理学",
                                "seniorId": "0101",
                                "stageId": "3",
                                "level": "3",
                                "displayOrder": "3",
                                "subList": []
                            }
                        ]
                    }
                ]
            }
        ]
    }

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