通过postgresql的Ltree字段类型实现目录结构的基本操作

将这种具有目录结构的excel表存储到数据库中，可以采用树型结构存储

DROP TABLE IF EXISTS "public"."directory_tree";
CREATE TABLE "public"."directory_tree" ("id" varchar(100) COLLATE "pg_catalog"."default","path" "public"."ltree","name" varchar(100) COLLATE "pg_catalog"."default" NOT NULL,"description" text COLLATE "pg_catalog"."default","updated_at" timestamp(6) DEFAULT now(),"created_at" timestamp(6) DEFAULT now()
)
;-- ----------------------------
-- Records of directory_tree
-- ----------------------------
INSERT INTO "public"."directory_tree" VALUES ('04e19944aa1d3d8bc13971b4488a4e0d', '04e19944aa1d3d8bc13971b4488a4e0d', 'root', 'root', '2023-08-09 02:11:35.145821', '2023-08-09 02:11:35.145821');

上面是建一张表，并且插入一条根节点。这里我们的id是mybatisPuls提供的UUID，并且我们的path字段采用祖id+爷id+父id+子id的结构。这是处理excel表格的工具类

package com.cdcas.utils;import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;import java.io.File;
import java.io.IOException;
import java.util.*;/*** @author jiao xn* @date 2023/4/20 22:44* @description*/
@Component
public class ExcelUtil {/*** 根据文件地址，读取指定 Excel 文件的内容，并以对象数组的方式返回** @param excelFilePath Excel 文件地址* @param sheetIndex 指定 Sheet 的索引值，从 0 开始* @param startLine 开始读取的行:从0开始* @param tailLine 去除最后读取的行* @return Excel 文件内容，对象数组*/public List<Map<String, String>> readExcelFile(String excelFilePath, Integer sheetIndex, Integer startLine, Integer tailLine) {Workbook workbook = this.generateWorkbook(excelFilePath);return this.readExcelSheetToObject(workbook, sheetIndex, startLine, tailLine);}/*** 从 MultipartFile 中读取 Excel 文件的内容，并以对象数组的方式返回** @param multipartFile MultipartFile 对象，一般是从前端接收* @param sheetIndex 指定 Sheet 的索引值，从 0 开始* @param startLine 开始读取的行:从0开始* @param tailLine 去除最后读取的行* @return Excel 文件内容，对象数组*/public List<Map<String, String>> readExcelFile(MultipartFile multipartFile, Integer sheetIndex, Integer startLine, Integer tailLine) {Workbook workbook = this.generateWorkbook(multipartFile);return this.readExcelSheetToObject(workbook, sheetIndex, startLine, tailLine);}/*** 生成 Workbook 对象** @param excelFilePath Excel 文件路径* @return Workbook 对象，允许为空*/private Workbook generateWorkbook(String excelFilePath) {Workbook workbook;try {File excelFile = new File(excelFilePath);workbook = WorkbookFactory.create(excelFile);} catch (IOException | InvalidFormatException e) {e.printStackTrace();throw new RuntimeException(e);}return workbook;}/*** 生成 Workbook 对象** @param multipartFile MultipartFile 对象* @return Workbook 对象*/private Workbook generateWorkbook(MultipartFile multipartFile) {Workbook workbook;try {workbook = WorkbookFactory.create(multipartFile.getInputStream());} catch (IOException | InvalidFormatException e) {e.printStackTrace();throw new RuntimeException(e);}return workbook;}/*** 读取指定 Sheet 中的数据** @param workbook Workbook 对象* @param sheetIndex 指定 Sheet 的索引值，从 0 开始* @param startLine 开始读取的行:从0开始* @param tailLine 去除最后读取的行* @return 指定 Sheet 的内容*/private List<Map<String, String>> readExcelSheetToObject(Workbook workbook,Integer sheetIndex, Integer startLine, Integer tailLine) {List<Map<String, String>> result = new ArrayList<>();Sheet sheet = workbook.getSheetAt(sheetIndex);// 获取第一行内容，作为标题内容Row titileRow = sheet.getRow(0);Map<String, String> titleContent = new LinkedHashMap<>();for (int i = 0; i < titileRow.getLastCellNum(); i++) {Cell cell = titileRow.getCell(i);titleContent.put(cell.getStringCellValue(), cell.getStringCellValue());}result.add(titleContent);// 获取正文内容Row row;for (Integer i = startLine; i < sheet.getLastRowNum() - tailLine + 1; i++) {row = sheet.getRow(i);Map<String, String> rowContent = new HashMap<>();for (Cell cell : row) {String returnStr;boolean isMergedCell  = this.isMergedCell(sheet, i, cell.getColumnIndex());if (isMergedCell) {returnStr = this.getMergedRegionValue(sheet, row.getRowNum(), cell.getColumnIndex());} else {returnStr = cell.getRichStringCellValue().getString();}rowContent.put(titileRow.getCell(cell.getColumnIndex()).getStringCellValue(), returnStr);}result.add(rowContent);}return result;}/*** 判断指定的单元格是否是合并单元格** @param sheet Excel 指定的 Sheet 表* @param row 行下标* @param column 列下标* @return 是否为合并的单元格*/private boolean isMergedCell(Sheet sheet, int row, int column) {int sheetMergeCount = sheet.getNumMergedRegions();for (int i = 0; i < sheetMergeCount; i++) {CellRangeAddress range = sheet.getMergedRegion(i);int firstColumn = range.getFirstColumn();int lastColumn = range.getLastColumn();int firstRow = range.getFirstRow();int lastRow = range.getLastRow();if(row >= firstRow && row <= lastRow && (column >= firstColumn && column <= lastColumn)){return true;}}return false;}/*** 获取合并单元格的值** @param sheet 指定的值* @param row 行号* @param column 列好* @return 合并单元格的值*/private String getMergedRegionValue(Sheet sheet, int row, int column){int sheetMergeCount = sheet.getNumMergedRegions();for(int i = 0 ; i < sheetMergeCount ; i++){CellRangeAddress ca = sheet.getMergedRegion(i);int firstColumn = ca.getFirstColumn();int lastColumn = ca.getLastColumn();int firstRow = ca.getFirstRow();int lastRow = ca.getLastRow();if(row >= firstRow && row <= lastRow && (column >= firstColumn && column <= lastColumn)) {Row fRow = sheet.getRow(firstRow);Cell fCell = fRow.getCell(firstColumn);return this.getCellValue(fCell) ;}}return null ;}/*** 获取单元格的值** @param cell Cell 对象* @return 单元格的值*/private String getCellValue(Cell cell){if(cell == null) {return "";}if(cell.getCellTypeEnum() == CellType.STRING){return cell.getStringCellValue();} else if(cell.getCellTypeEnum() == CellType.BOOLEAN){return String.valueOf(cell.getBooleanCellValue());} else if(cell.getCellTypeEnum() == CellType.FORMULA){return cell.getCellFormula() ;} else if(cell.getCellTypeEnum() == CellType.NUMERIC){return String.valueOf(cell.getNumericCellValue());}return "";}
}

下面是将生成的List<Map<String, String>> excel数据插入到excel表中的工具类

package com.cdcas;import com.cdcas.mapper.DirectoryTreeMapper;
import com.cdcas.pojo.DirectoryTree;
import com.cdcas.utils.ExcelDataUtil;
import com.cdcas.utils.ExcelUtil;
import org.junit.jupiter.api.Test;
import org.junit.platform.commons.util.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.util.CollectionUtils;import java.io.FileInputStream;
import java.util.HashSet;
import java.util.List;
import java.util.Map;/*** @version 1.0* @Author zhaozhixin* @Date 2023/8/7 15:01* @注释*/   //983
@SpringBootTest
public class Test2 {/*** 替换和插入** @param parentPath* @param directoryTree*/private String Insert(String parentPath, DirectoryTree directoryTree, String name) {directoryTree.setName(name);directoryTree.setDescription(parentPath);directoryTreeMapper.insert(directoryTree);directoryTree.setPath(parentPath + "." + directoryTree.getId());directoryTreeMapper.updateDirectoryTree(directoryTree);return directoryTree.getId();}/*** 通过名称查询父路径** @param name* @return*/private String getParentPathByName(String name) {DirectoryTree parent = directoryTreeMapper.getOneByName(name);return parent.getPath();}@Testpublic void get() {String path = directoryTreeMapper.getPath(1);System.out.println(path);}@Autowiredprivate ExcelUtil excelUtil;@Autowiredprivate ExcelDataUtil excelDataUtil;@Autowiredprivate DirectoryTreeMapper directoryTreeMapper;@Testpublic void insert() throws Exception {//读取一个excelList<Map<String, String>> maps = excelUtil.readExcelFile("C:\\Users\\20745\\Desktop\\git库\\gitee\\pg-demo-itree\\src\\main\\resources\\国土规划目录树.xlsx", 0, 1, 0);maps.remove(0);System.out.println(maps);for (Map<String, String> map : maps) {String A1 = map.get("A1");String A2 = map.get("A2");String A3 = map.get("A3");String A4 = map.get("A4");String A5 = map.get("A5");String A6 = map.get("A6");String A7 = map.get("A7");String A8 = map.get("A8");String A9 = map.get("A9");StringBuilder parentPath = new StringBuilder();//用来拼接父节点idparentPath.append("04e19944aa1d3d8bc13971b4488a4e0d");//这是根节点idif (A1 != null && !"".equals(A1)) {//二级节点  根节点为rootDirectoryTree directoryTree = new DirectoryTree();String name = A1;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A2 != null && !"".equals(A2)) {//拿到所有同名的行DirectoryTree directoryTree = new DirectoryTree();String name = A2;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A3 != null && !"".equals(A3)) {DirectoryTree directoryTree = new DirectoryTree();String name = A3;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A4 != null && !"".equals(A4)) {DirectoryTree directoryTree = new DirectoryTree();String name = A4;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A5 != null && !"".equals(A5)) {DirectoryTree directoryTree = new DirectoryTree();String name = A5;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A6 != null && !"".equals(A6)) {DirectoryTree directoryTree = new DirectoryTree();String name = A6;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A7 != null && !"".equals(A7)) {DirectoryTree directoryTree = new DirectoryTree();String name = A7;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A8 != null && !"".equals(A8)) {DirectoryTree directoryTree = new DirectoryTree();String name = A8;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}if (A9 != null && !"".equals(A9)) {DirectoryTree directoryTree = new DirectoryTree();String name = A9;String id = isExtis(name, directoryTree, parentPath.toString());if (id==null){}else {parentPath.append(".").append(id);}}}}/*** 判断一个同名的是否存在在其它数 返回当前节点id* @param name* @param directoryTree* @param parentPath*/private String isExtis(String name,DirectoryTree directoryTree,String parentPath){//最终标识  开始表明不存在boolean isExtis = false;//获取到所有的和name同名的行List<DirectoryTree> oneByNames = directoryTreeMapper.getListByName(name);//如果没有同名的直接插入if (CollectionUtils.isEmpty(oneByNames)){directoryTree.setName(name);directoryTree.setDescription(parentPath);directoryTreeMapper.insert(directoryTree);directoryTree.setPath(parentPath+"."+directoryTree.getId());directoryTreeMapper.updateDirectoryTree(directoryTree);return directoryTree.getId();}//如果有同名的，需要判断父路径是否相同String path = "";int lastIndexOf = 0;for (DirectoryTree oneByName : oneByNames) {if (oneByName!=null) {path = oneByName.getPath();lastIndexOf = path.lastIndexOf(".");}//重复的数据应该也要被插入进去  查出的父路径传入的父路径进行对比if (path.substring(0,lastIndexOf).equals(parentPath)){isExtis = true;}}//最后如果同名的数据但是父路径不相同，就需要插入进去if (!isExtis){directoryTree.setName(name);directoryTree.setDescription(parentPath);directoryTreeMapper.insert(directoryTree);directoryTree.setPath(parentPath+"."+directoryTree.getId());directoryTreeMapper.updateDirectoryTree(directoryTree);return directoryTree.getId();}return oneByNames.get(oneByNames.size()-1).getId();}//查看重复条数和 总条数@Testpublic void look() throws Exception {FileInputStream fileInputStream = new FileInputStream("C:\\Users\\20745\\Desktop\\git库\\gitee\\pg-demo-itree\\src\\main\\resources\\国土规划目录树.xlsx");List<Map<String, String>> maps = excelDataUtil.readExcel(fileInputStream);int count = 0;HashSet<String> set = new HashSet();for (Map<String, String> map : maps) {if (StringUtils.isNotBlank(map.get("A1"))) {set.add(map.get("A1"));count++;}if (StringUtils.isNotBlank(map.get("A2"))) {set.add(map.get("A2"));count++;}if (StringUtils.isNotBlank(map.get("A3"))) {set.add(map.get("A3"));count++;}if (StringUtils.isNotBlank(map.get("A4"))) {set.add(map.get("A4"));count++;}if (StringUtils.isNotBlank(map.get("A5"))) {set.add(map.get("A5"));count++;}if (StringUtils.isNotBlank(map.get("A6"))) {set.add(map.get("A6"));count++;}if (StringUtils.isNotBlank(map.get("A7"))) {set.add(map.get("A7"));count++;}if (StringUtils.isNotBlank(map.get("A8"))) {set.add(map.get("A8"));count++;}if (StringUtils.isNotBlank(map.get("A9"))) {set.add(map.get("A9"));count++;}}System.out.println(count);System.out.println(set.size());}
}

最后插入的数据大概是这样

注意这里的path！！！！！是id拼起来的具有目录层次的！！

这些关于目录树的基本操作，楼主写了一个小demo放在gitee上面了。本人不会算法，里面写的很菜见谅哈哈。喜欢的点个赞谢谢<_.>! gitee地址：pg-demo-itree: 基于postgresql的Itree功能实现目录树的操作 (gitee.com)