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
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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：
2.创建java实体
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package org.labib.pojo;import java.util.Date;public class Area { //区域ID private 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
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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<Area> queryAreaAll(); List<Map<String, String>> queryMap();} |
4.创建service
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@Service("AreaService")public class AreaService { @Autowired private AreaMapper areaMapper; //修建 public String queryArea(){ List<Area> mapList = areaMapper.queryAreaAll(); JSONArray result = ListToTree.buildTree(JSONArray.parseArray(JSON.toJSONString(mapList)),"areaCode","superiorCode","children"); return result.toJSONString(); } //修建 public String queryAreaCode(){ List<Map<String, String>> 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：
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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null if (aVal.get(pid) != null) { pidStr = aVal.get(pid).toString(); } //从hash这个对象中获取父级对象 parent JSONObject 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
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@RestControllerpublic class AreaController { @Resource private AreaService areaService; @RequestMapping(value = "/area",method = RequestMethod.POST) public String queryArea() { return areaService.queryArea(); } @RequestMapping(value = "/area1",method = RequestMethod.POST) public String queryAreaDemo() { return areaService.queryAreaCode(); }} |
6.接口测试
测试结果：
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/qq_45256805/article/details/119565617
