Java利用poi 3.9对excel进行读写操作的工具类支持多Sheet
一、什么是POI
POI全称PoorObfuscation Implementation ，是Apache组件的一个开源项目，可以对微软的Office一系列办公软件进行读写操作。
官方下载地址：https://poi.apache.org/download.html，目前最新版本为POI 5.2.1。
本文实例对应的POI版本为3.9
二、 项目pom文件
org.apache.poi
poi
3.9
org.apache.poi
poi-ooxml
3.9
org.apache.commons
commons-collections4
4.2
三、生成Excel 工具类
package org.zhao.component;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.collections4.MapUtils;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.*;
import java.util.*;
/**
* 生成Excel
*
* @author Administrator
* @date 2022年03月11日
*/
public class WriteExcelComponent {
private static String getFileExtname(String filename) {
return filename.substring(filename.lastIndexOf(".") + 1).toLowerCase();
}
@SuppressWarnings("unchecked")
public static void writeExcel(String filePath, List> dataList) throws Exception {
File file = new File(filePath);
if (file.exists()) {
return;
}
String fileName = file.getName();
String fileSuffix = getFileExtname(fileName);
Workbook workbook = null;
if ("xls".equals(fileSuffix)) {
workbook = new HSSFWorkbook();
}
if ("xlsx".equals(fileSuffix)) {
workbook = new XSSFWorkbook();
}
if (workbook == null) {
return;
}
for (int sheetIndex = 0; sheetIndex < dataList.size(); sheetIndex++) {
Sheet sheet = workbook.createSheet();
Map data = dataList.get(sheetIndex);
String sheetName = "Sheet" + (sheetIndex + 1);
String dataSheetName = MapUtils.getString(data, "sheetName", "");
if (dataSheetName != null && dataSheetName.length() != 0) {
sheetName = dataSheetName;
}
workbook.setSheetName(sheetIndex, sheetName);
List sheetHeader = (List) MapUtils.getObject(data, "sheetHeader", new ArrayList<>());
int startRowIndex = 0;
if (CollectionUtils.isNotEmpty(sheetHeader)) {
CellStyle cellStyle = workbook.createCellStyle();
Font font = workbook.createFont();
font.setBoldweight(Font.BOLDWEIGHT_BOLD);
cellStyle.setFont(font);
Row row = sheet.createRow(0);
for (int headerIndex = 0; headerIndex < sheetHeader.size(); headerIndex++) {
Cell cell = row.createCell(headerIndex, Cell.CELL_TYPE_STRING);
cell.setCellValue(String.valueOf(sheetHeader.get(headerIndex)));
cell.setCellStyle(cellStyle);
}
startRowIndex = 1;
}
List> rows = (List>) MapUtils.getObject(data, "sheetRows", new ArrayList<>());
for (int rowIndex = 0; rowIndex < rows.size(); rowIndex++) {
Row row = sheet.createRow(startRowIndex + rowIndex);
List cellItems = rows.get(rowIndex);
for (int cellIndex = 0; cellIndex < cellItems.size(); cellIndex++) {
Cell cell = row.createCell(cellIndex, Cell.CELL_TYPE_STRING);
cell.setCellValue(cellItems.get(cellIndex));
sheet.setColumnWidth(cellIndex, 80 * 50);
}
}
}
FileOutputStream fos = new FileOutputStream(filePath);
workbook.write(fos);
fos.close();
}
} 四、读取Excel 工具类
package org.zhao.component;
import org.apache.commons.collections4.MapUtils;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.*;
import java.util.*;
/**
* Excel 读取excel中的数据
*
* @author Administrator
* @date 2022年03月11日
*/
public class ReadExcelComponent {
private static String getFileExtname(String filename) {
return filename.substring(filename.lastIndexOf(".") + 1).toLowerCase();
}
/**
* 读取某个sheet中的数据
*
* @param path 文件路径
* @param sheetNum sheet号
*/
public static Map readExcelData(String path, int sheetNum) {
List> dataList = readExcelDatas(path);
if (dataList.size() == 0) {
return null;
}
return dataList.stream().filter(map -> MapUtils.getIntValue(map, "sheetIndex", 0) == sheetNum).findAny().orElse(null);
}
/**
* 读取Excel中所有数据 多个sheet
*
* @param path 文件路径
*/
public static List> readExcelDatas(String path) {
List> dataList = new ArrayList<>();
if (path == null || path.length() == 0) {
return dataList;
}
File file = new File(path);
String fileName = file.getName();
String fileSuffix = getFileExtname(fileName);
Workbook workbook = null;
try {
if ("xls".equals(fileSuffix)) {
workbook = new HSSFWorkbook(new FileInputStream(file));
}
if ("xlsx".equals(fileSuffix)) {
workbook = new XSSFWorkbook(new FileInputStream(file));
}
} catch (IOException e) {
e.printStackTrace();
}
if (workbook == null) {
return dataList;
}
List workbookSheets = getWorkbookSheetList(workbook);
for (int sheetIndex = 0; sheetIndex < workbookSheets.size(); sheetIndex++) {
Sheet sheet = workbookSheets.get(sheetIndex);
List sheetRowList = getSheetRowList(sheet);
String sheetName = sheet.getSheetName();
Map sheetDataList = new LinkedHashMap<>();
List> rows = new ArrayList<>();
sheetRowList.forEach(row -> {
short firstCellNum = row.getFirstCellNum();
short lastCellNum = row.getLastCellNum();
List cellDataList = new ArrayList<>();
for (int cellIndex = firstCellNum; cellIndex < lastCellNum; cellIndex++) {
Cell cell = row.getCell(cellIndex);
cellDataList.add(getCellValue(cell));
}
rows.add(cellDataList);
});
sheetDataList.put("sheetName", sheetName);
sheetDataList.put("sheetIndex", sheetIndex + 1);
sheetDataList.put("sheetRows", rows);
dataList.add(sheetDataList);
}
return dataList;
}
private static String getCellValue(Cell cell) {
String cellValue = "";
if (cell == null) {
return "";
}
try {
int cellType = cell.getCellType();
/*Numeric 数字类型*/
if (HSSFCell.CELL_TYPE_NUMERIC == cellType) {
cellValue = String.valueOf(cell.getNumericCellValue());
}
/*字符串*/
if (HSSFCell.CELL_TYPE_STRING == cellType) {
cellValue = cell.getStringCellValue();
}
/*公式 Formula*/
if (HSSFCell.CELL_TYPE_FORMULA == cellType) {
cellValue = cell.getCellFormula();
}
/*空行*/
if (HSSFCell.CELL_TYPE_BLANK == cellType) {
cellValue = "";
}
/*布尔类型*/
if (HSSFCell.CELL_TYPE_BOOLEAN == cellType) {
cellValue = String.valueOf(cell.getBooleanCellValue());
}
/*Error Cell type */
if (HSSFCell.CELL_TYPE_ERROR == cellType) {
cellValue = String.valueOf(cell.getErrorCellValue());
}
} catch (Exception e) {
e.printStackTrace();
}
return cellValue;
}
/*获取sheet 中行数据*/
private static List getSheetRowList(Sheet sheet) {
List items = new ArrayList<>();
if (sheet == null) {
return items;
}
int physicalNumberOfRows = sheet.getPhysicalNumberOfRows();
for (int rowIndex = 0; rowIndex < physicalNumberOfRows; rowIndex++) {
Row row = sheet.getRow(rowIndex);
items.add(row);
}
return items;
}
/*获取excel 中 sheet*/
private static List getWorkbookSheetList(Workbook workbook) {
List items = new ArrayList<>();
if (workbook == null) {
return items;
}
int numberOfSheets = workbook.getNumberOfSheets();
for (int sheetIndex = 0; sheetIndex < numberOfSheets; sheetIndex++) {
Sheet sheet = workbook.getSheetAt(sheetIndex);
items.add(sheet);
}
return items;
}
}
五、运行实例
package org.zhao;
import org.zhao.component.ReadExcelComponent;
import org.zhao.component.WriteExcelComponent;
import java.util.*;
/**
* @author Administrator
* @date 2022年03月11日
*/
public class Main {
public static void writeDataToExcel() {
List> dataList = new ArrayList<>();
Map sheet_1 = new HashMap<>();
sheet_1.put("sheetName", "语文成绩");
sheet_1.put("sheetHeader", Arrays.asList("学号", "姓名", "分数"));
List> rows = new ArrayList<>();
rows.add(Arrays.asList("0001", "小张", "60"));
rows.add(Arrays.asList("0002", "小明", "80"));
rows.add(Arrays.asList("0003", "小王", "90"));
sheet_1.put("sheetRows", rows);
dataList.add(sheet_1);
Map sheet_2 = new HashMap<>();
sheet_2.put("sheetName", "数学成绩");
sheet_2.put("sheetHeader", Arrays.asList("学号", "姓名", "分数"));
List> rows2 = new ArrayList<>();
rows2.add(Arrays.asList("0001", "小张", "90"));
rows2.add(Arrays.asList("0002", "小明", "86"));
rows2.add(Arrays.asList("0003", "小王", "95"));
sheet_2.put("sheetRows", rows2);
dataList.add(sheet_2);
try {
WriteExcelComponent.writeExcel("D:/成绩单.xls", dataList);
System.out.println("创建成功");
} catch (Exception e) {
e.printStackTrace();
}
}
public static void readExcelData() {
List> allItems = ReadExcelComponent.readExcelDatas("D:/成绩单.xls");
System.out.println("allItems = " + allItems);
Map sheet2Items = ReadExcelComponent.readExcelData("D:/成绩单.xls", 2);
System.out.println("sheet2Items = " + sheet2Items);
}
public static void main(String[] args) {
// writeDataToExcel();
readExcelData();
}
} 六、完整实例下载地址：
https://download.csdn.net/download/networkTalent/84981699