java实现省市区转换成树形结构 java实现省市区转换成树形结构

本文实例为大家分享了java实现省市区转换成树形结构的具体代码，供大家参考，具体内容如下
前言：为什我想写这篇博客呢？第一方面是记录，另一方面是分享。
1.创建数据库表
1.建表语句

CREATE TABLE `area`(`AREA_CODE` varchar(16) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '区域ID',`AREA_NAME` varchar(512) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '区域名称',`SUPERIOR_CODE` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '父级代码',`AREA_LEVEL` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '级别',`AREA_SORT` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '排序',`REMARK` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '备注',`DELETE_FLAG` varchar(1) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '删除标识',`CREATED_BY` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '创建人',`CREATION_TIME` timestamp(0) NOT NULL DEFAULT CURRENT_TIMESTAMP(0) ON UPDATE CURRENT_TIMESTAMP(0) COMMENT '创建时间',`UPDATED_BY` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '更新人',`UPDATE_TIME` timestamp(0) NOT NULL DEFAULT '2020-01-01 00:00:00' COMMENT '更新时间',PRIMARY KEY (`AREA_CODE`) USING BTREE,UNIQUE INDEX `UK_T_PUB_AREA_AREA_CODE`(`AREA_CODE`) USING BTREE,INDEX `IDX_T_PUB_AREA_AREA_LEVEL`(`AREA_LEVEL`) USING BTREE,INDEX `IDX_T_PUB_AREA_SUPERIOR_CODE`(`SUPERIOR_CODE`) USING BTREE) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci COMMENT = '区域表' ROW_FORMAT = DYNAMIC; SET FOREIGN_KEY_CHECKS = 1;

建表完成的table样式：

文章图片

2.创建java实体

package org.labib.pojo; import java.util.Date; public class Area {//区域IDprivate String areaCode; //区域名称private String areaName; //父级代码private String superiorCode; //级别private String areaLevel; //排序private String areaSort; //备注private String remark; //删除标识private String deleteFlag; //创建人private String createdBy; //创建时间private Date creationTime; //更新人private String updatedBy; //更新时间private Date updateTime; public String getAreaCode() {return areaCode; }public void setAreaCode(String areaCode) {this.areaCode = areaCode == null ? null : areaCode.trim(); }public String getAreaName() {return areaName; }public void setAreaName(String areaName) {this.areaName = areaName == null ? null : areaName.trim(); }public String getSuperiorCode() {return superiorCode; }public void setSuperiorCode(String superiorCode) {this.superiorCode = superiorCode == null ? null : superiorCode.trim(); }public String getAreaLevel() {return areaLevel; }public void setAreaLevel(String areaLevel) {this.areaLevel = areaLevel == null ? null : areaLevel.trim(); }public String getAreaSort() {return areaSort; }public void setAreaSort(String areaSort) {this.areaSort = areaSort == null ? null : areaSort.trim(); }public String getRemark() {return remark; }public void setRemark(String remark) {this.remark = remark == null ? null : remark.trim(); }public String getDeleteFlag() {return deleteFlag; }public void setDeleteFlag(String deleteFlag) {this.deleteFlag = deleteFlag == null ? null : deleteFlag.trim(); }public String getCreatedBy() {return createdBy; }public void setCreatedBy(String createdBy) {this.createdBy = createdBy == null ? null : createdBy.trim(); }public Date getCreationTime() {return creationTime; }public void setCreationTime(Date creationTime) {this.creationTime = creationTime; }public String getUpdatedBy() {return updatedBy; }public void setUpdatedBy(String updatedBy) {this.updatedBy = updatedBy == null ? null : updatedBy.trim(); }public Date getUpdateTime() {return updateTime; }public void setUpdateTime(Date updateTime) {this.updateTime = updateTime; }}

3.创建mapper

package org.labib.mapper; import org.labib.pojo.Area; import java.util.List; import java.util.Map; public interface AreaMapper {int deleteByPrimaryKey(String areaCode); int insert(Area record); int insertSelective(Area record); Area selectByPrimaryKey(String areaCode); int updateByPrimaryKeySelective(Area record); int updateByPrimaryKey(Area record); List queryAreaAll(); List queryMap(); }

4.创建service

@Service("AreaService")public class AreaService {@Autowiredprivate AreaMapper areaMapper; //修建public String queryArea(){List mapList = areaMapper.queryAreaAll(); JSONArray result = ListToTree.buildTree(JSONArray.parseArray(JSON.toJSONString(mapList)),"areaCode","superiorCode","children"); return result.toJSONString(); }//修建public String queryAreaCode(){List mapList = areaMapper.queryMap(); JSONArray result = ListToTree.buildTree(JSONArray.parseArray(JSON.toJSONString(mapList)),"value","superiorCode","children"); return result.toJSONString(); }}

并附上转换成树形结构的工具类：

public class ListToTree {public static JSONArray buildTree(JSONArray arr, String id, String pid, String Chirden) {//新建一个JSONArray来接收组装成树形结构的返回值JSONArray jsonArray = new JSONArray(); //新建一个JSONObject对象JSONObject hash = new JSONObject(); //将数组转换为object格式for (int i = 0; i < arr.size(); i++) {//获取当前的JSON对象JSONObject json = (JSONObject) arr.get(i); //把当前id作为键，当前JSON对象作为值 put回hash这个Object对象中//这里的put方法类似于map的put方法hash.put(json.getString(id), json); }//遍历结果集for (int j = 0; j < arr.size(); j++) {//单条记录JSONObject aVal = (JSONObject) arr.get(j); //在hash中取出key为单条记录中pid的值String pidStr = ""; //如果父级id不等于nullif (aVal.get(pid) != null) {pidStr = aVal.get(pid).toString(); }//从hash这个对象中获取父级对象parentJSONObject hashParent = (JSONObject) hash.get(pidStr); //如果记录的pid存在，则说明它有父节点，将她添加到孩子节点的集合中if (hashParent != null) {//检查是否有child属性if (hashParent.get(Chirden) != null) {//有子节点则先将子节点取出JSONArray children = (JSONArray) hashParent.get(Chirden); //然后把当前这个对象放进子节点之中children.add(aVal); //最后把子节点在放回父节点之中hashParent.put(Chirden, children); } else {//无子节点则新建一个子节点JSONArray children = new JSONArray(); //然后再把当前对象放进去children.add(aVal); //最后在放回父节点之中hashParent.put(Chirden, children); }} else {jsonArray.add(aVal); }}return jsonArray; }}

5.创建controller

@RestControllerpublic class AreaController {@Resourceprivate AreaService areaService; @RequestMapping(value = "https://www.it610.com/area",method = RequestMethod.POST)public String queryArea() {return areaService.queryArea(); }@RequestMapping(value = "https://www.it610.com/area1",method = RequestMethod.POST)public String queryAreaDemo() {return areaService.queryAreaCode(); }}

6.接口测试
测试结果：