1. Java POI 读取、写入Excel(包括样式)的工具类Utils
2021/10/23 17:09:25
本文主要是介绍1. Java POI 读取、写入Excel(包括样式)的工具类Utils,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
在工作中经常会遇到操作excel的需求,对于格式简单、统一的excel可以选择EasyExcel来实现功能,很简单方便;而对于复杂的excel文件,如有各式各样的合并单元格、表头不固定、行列跟随业务数据动态变化……格式变幻多端的文件,easyExcel就显得无能为力了,选择poi就可以解决此问题了。
这里贴上在工作中解决问题时,自己封装的工具类,方便大家查阅:
目录
一、读取Excel、写入Excel文件工具类
二、导出Excel文件的样式设置工具类
三、写入Excel简单示例
一、读取、写入Excel工具类
注:poi版本为org.apache.poi:4.1.0
/** * 工具类-使用poi读取Excel */ @Slf4j public class ExcelUtilByPOI { private static final String EXCEL_XLS = "xls"; private static final String EXCEL_XLSX = "xlsx"; /** * 读取excel文件中的全部表格 * 描述:适用于没有单元格合并的excel,并且 (titleOfRow,titleOfColumn)位置为读取内容的起始位置的情况 * 每一行构成一个map,key值是列标题,value是列值。没有值的单元格其value值为null * 返回结果最外层list对应excel文件,第二层Iterable对应sheet页,第三层map对应sheet页中一行 * * @param filePath 文件路径 * @param sheetCnt 读取的文件中前sheetCnt个sheet数据。如果值为-1,则读取所有的sheet,否则,读取前sheetCnt个sheet的数据。 * @return * @throws Exception */ public static List<List<Map<String, Object>>> readExcelWithFiexPos(String filePath, int titleInRow, int titleInColumn, int sheetCnt) throws IOException { Workbook wb = null; try { List<List<Map<String, Object>>> excelData = new ArrayList<>(); if (filePath.endsWith(EXCEL_XLS) || filePath.endsWith(EXCEL_XLSX)) { File file = new File(filePath); wb = getWorkbook(file); int sheetSize = sheetCnt == -1 ? wb.getNumberOfSheets() : sheetCnt; //遍历sheet for (int i = 0; i < sheetSize; i++) { Sheet sheet = wb.getSheetAt(i); List<Map<String, Object>> theSheetData = readSheet(sheet, titleInRow, titleInColumn); excelData.add(theSheetData); } } else { log.error("读取的不是Excel文件"); } return excelData; } catch (FileNotFoundException e) { throw e; } finally { if (wb != null) { wb.close(); } } } /** * 读取excel文件中的全部表格 * 描述:适用于没有单元格合并的excel,并且 以fiexedValue在sheet中的位置为读取内容起始位置的情况 * 每一行构成一个map,key值是列标题,value是列值。没有值的单元格其value值为null * 返回结果最外层list对应excel文件,第二层Iterable对应sheet页,第三层map对应sheet页中一行 * * @param fixedValue 固定值(第一个列标题) * @param filePath 文件路径 * @param sheetCnt 读取的文件中前sheetCnt个sheet数据。如果值为-1,则读取所有的sheet,否则,读取前sheetCnt个sheet的数据。 * @return * @throws Exception */ public static List<List<Map<String, Object>>> readExcelWithFiexedTitle(String filePath, String fixedValue, int sheetCnt) throws IOException { Workbook wb = null; try { List<List<Map<String, Object>>> excelData = new ArrayList<>(); if (filePath.endsWith(EXCEL_XLS) || filePath.endsWith(EXCEL_XLSX)) { File file = new File(filePath); wb = getWorkbook(file); int sheetSize = sheetCnt == -1 ? wb.getNumberOfSheets() : sheetCnt; //遍历sheet for (int i = 0; i < sheetSize; i++) { Sheet sheet = wb.getSheetAt(i); List<Integer> posForSheet = readPosForValue(sheet, fixedValue); List<Map<String, Object>> theSheetData = readSheet(sheet, posForSheet.get(0), posForSheet.get(1)); excelData.add(theSheetData); } } else { log.error("读取的不是Excel文件"); } return excelData; } catch (FileNotFoundException e) { throw e; } finally { if (wb != null) { wb.close(); } } } /** * 读取excel文件个sheet第rowNum行的内容,从firstColNum列开始往后读取到第lastColNum列 * * @param filePath * @param rowNum * @param firstColNum * @param lastColNum * @return */ public static List<List<Object>> readRowData(String filePath, int rowNum, int firstColNum, int lastColNum) throws IOException { List<List<Object>> dataList = new ArrayList<>(); File file = new File(filePath); Workbook wb = getWorkbook(file); int sheetCnt = wb.getNumberOfSheets(); for (int cnt = 0; cnt < sheetCnt; cnt++) { //遍历每一个sheet Sheet sheet = wb.getSheetAt(cnt); Row row = sheet.getRow(rowNum); lastColNum = lastColNum == -1 ? row.getLastCellNum() : lastColNum; //如果没有lastColNum则为其值为最后一列 List<Object> sheetContentList = new ArrayList<>(); Cell cell = null; String value = null; for (int i = firstColNum; i < lastColNum; i++) { //读取指定行的内容 cell = row.getCell(i); value = readCellByType(cell); sheetContentList.add(value); } dataList.add(sheetContentList); } return dataList; } /** * 读取给定sheet的内容 * 描述: * 读取excel文件中的指定名称的表格 用于没有单元格合并的表格,且 (titleOfRow,titleOfColumn)位置为读取内容的起始位置的情况 * 每一行构成一个map(key值是列标题,value是列值)。没有值的单元格其value值为null。 * 返回结果最外层的list对应一个sheet页,第二层的map对应sheet页中的一行。 * * @param sheet * @return */ private static List<Map<String, Object>> readSheet(Sheet sheet, int titleInRow, int titleInColumn) { List<Map<String, Object>> sheetList = null; sheetList = new ArrayList<Map<String, Object>>(); List<String> titles = new ArrayList<>(); int rowSize = sheet.getLastRowNum() + 1; for (int i = titleInRow; i < rowSize; i++) { Row row = sheet.getRow(i); if (row == null) continue; ;//略过空行 int cellSize = row.getLastCellNum(); if (i == titleInRow) //标题行 { for (int j = titleInColumn; j < cellSize; j++) { Cell cell = row.getCell(j); if (cell != null) { titles.add(cell.toString()); } } } else { //对应每一行的数据 Map<String, Object> rowDataMap = new LinkedHashMap<>(); for (int j = titleInColumn; j < titleInColumn + titles.size(); j++) { Cell cell = row.getCell(j); String value = null; CellType cellType = null; if (cell == null) { continue; } cellType = cell.getCellTypeEnum(); switch (cellType) { case STRING: // value = cell.getRichStringCellValue().getString(); value = cell.getStringCellValue(); break; case NUMERIC: //包含日期和普通数字 if (DateUtil.isCellDateFormatted(cell)) { Date date = cell.getDateCellValue(); DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); value = df.format(date); } else { double cellValue = cell.getNumericCellValue(); value = String.valueOf(cellValue); // 下面的代码,会自动舍弃读取单元格中显示的值(可能是做了round()之后的结果),不是单元格中最原本的值 /*NumberFormat nf = NumberFormat.getInstance(); String tmpValue = nf.format(cell.getNumericCellValue()); if (tmpValue.indexOf(",") >= 0) { tmpValue = tmpValue.replaceAll(",", ""); } value = tmpValue;*/ } break; case FORMULA: // cell.getCellFormula(); cell.setCellType(CellType.STRING); value = cell.getStringCellValue(); break; case BOOLEAN: value = String.valueOf(cell.getBooleanCellValue()); break; default: if (cell != null) { value = cell.toString(); } } String key = titles.get(j - titleInColumn); rowDataMap.put(key, value); } sheetList.add(rowDataMap); } } return sheetList; } /** * 读取sheet中指定值的位置 * * @param sheet * @return */ private static List<Integer> readPosForValue(Sheet sheet, String fixedValue) { List<Integer> posList = new ArrayList(); Object value = null; for (int j = 0; j < sheet.getPhysicalNumberOfRows(); j++) { // 获取每行 XSSFRow row = (XSSFRow) sheet.getRow(j); if (row != null) { for (int k = 0; k < sheet.getRow(0).getPhysicalNumberOfCells(); k++) { // 获取每个单元格 Cell cell = row.getCell(k); if (cell == null) { continue; } CellType cellTypeEnum = cell.getCellTypeEnum(); switch (cellTypeEnum) { case STRING: value = cell.getRichStringCellValue().getString(); break; // case Cell.CELL_TYPE_NUMERIC: case NUMERIC: if (DateUtil.isCellDateFormatted(cell)) { value = cell.getDateCellValue(); } else { double cellValue = cell.getNumericCellValue(); value = String.valueOf(cellValue); /* // 下面的代码,会自动舍弃读取单元格中显示的值(可能是做了round()之后的结果),不是单元格中最原本的值 NumberFormat nf = NumberFormat.getInstance(); String tmpValue = nf.format(cell.getNumericCellValue()); if (tmpValue.indexOf(",") >= 0) { tmpValue = tmpValue.replaceAll(",", ""); } value = tmpValue;*/ } break; case BOOLEAN: value = cell.getBooleanCellValue(); break; case FORMULA: value = cell.getCellFormula(); break; default: value = ""; break; } if (fixedValue.equals(value.toString())) { posList.add(cell.getRowIndex()); posList.add(cell.getColumnIndex()); break; } } } if (!BeanUtil.isEmpty(posList)) { break; } } return posList; } /** * 根据excel的版本,获取相应的Workbook * * @param file * @return */ public static Workbook getWorkbook(File file) throws IOException { Workbook wb = null; InputStream fis = new FileInputStream(file); if (file.getName().endsWith(EXCEL_XLS)) //2003 { wb = new HSSFWorkbook(fis); } else if (file.getName().endsWith(EXCEL_XLSX)) { wb = new XSSFWorkbook(fis);//2007 2010 } if (fis != null) { fis.close(); } return wb; } /** * 判断指定的单元格是否是合并单元格 * * @param sheet * @param row 行下标 * @param column 列下标 * @return */ public static boolean isMergedRegion(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) { if (column >= firstColumn && column <= lastColumn) { return true; } } } return false; } /** * 获取合并单元格的值 * * @param sheet * @param row * @param column * @return */ public static String getMergedCellValue(Sheet sheet, int row, int column) { String value = null; int mergedCellCnt = sheet.getNumMergedRegions(); for (int i = 0; i < mergedCellCnt; i++) { CellRangeAddress mergedCell = sheet.getMergedRegion(i); int firstColumn_pos = mergedCell.getFirstColumn(); int lastColumn_pos = mergedCell.getLastColumn(); int firstRow_pos = mergedCell.getFirstRow(); int lastRow_pos = mergedCell.getLastRow(); if (row >= firstRow_pos && row <= lastRow_pos) { if (column >= firstColumn_pos && column <= lastColumn_pos) { Row firstRow = sheet.getRow(firstRow_pos); Cell cell = firstRow.getCell(firstColumn_pos); if (cell == null) { continue; } CellType cellType = cell.getCellTypeEnum(); switch (cellType) { case STRING: // value = cell.getRichStringCellValue().getString(); value = cell.getStringCellValue(); break; case NUMERIC: //包含日期和普通数字 if (DateUtil.isCellDateFormatted(cell)) { Date date = cell.getDateCellValue(); DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); value = df.format(date); } else { double cellValue = cell.getNumericCellValue(); value = String.valueOf(cellValue); /* 下面的代码,会自动舍弃读取单元格中显示的值(可能是做了round()之后的结果),不是单元格中最原本的值 NumberFormat nf = NumberFormat.getInstance(); String tmpValue = nf.format(cell.getNumericCellValue()); if (tmpValue.indexOf(",") >= 0) { tmpValue = tmpValue.replaceAll(",", ""); } value = tmpValue;*/ } break; case FORMULA: // cell.getCellFormula(); cell.setCellType(CellType.STRING); value = cell.getStringCellValue(); break; case BOOLEAN: value = String.valueOf(cell.getBooleanCellValue()); break; default: if (cell != null) { value = cell.toString(); } } return cell == null || value == null ? "" : value; } } } return null; } /** * 读取单元格的类型 * * @param cell * @return */ public static String readCellByType(Cell cell) { if (cell == null) { return null; } CellType cellType = cell.getCellTypeEnum(); String value = null; switch (cellType) { case STRING: // value = cell.getRichStringCellValue().getString(); value = cell.getStringCellValue(); break; case NUMERIC: //包含日期和普通数字 if (DateUtil.isCellDateFormatted(cell)) { Date date = cell.getDateCellValue(); DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); value = df.format(date); } else { double cellValue = cell.getNumericCellValue(); value = String.valueOf(cellValue); /* 下面的代码,会自动舍弃读取单元格中显示的值(可能是做了round()之后的结果),不是单元格中最原本的值 NumberFormat nf = NumberFormat.getInstance(); String tmpValue = nf.format(cell.getNumericCellValue()); if (tmpValue.indexOf(",") >= 0) { tmpValue = tmpValue.replaceAll(",", ""); } value = tmpValue;*/ } break; case FORMULA: // cell.getCellFormula(); cell.setCellType(CellType.STRING); value = cell.getStringCellValue(); break; case BOOLEAN: value = String.valueOf(cell.getBooleanCellValue()); break; default: if (cell != null) { value = cell.toString(); } } return cell == null || value == null ? "" : value; } /** * 读取一个excel文件中所有的sheet名字列表 * * @param filePath 文件路径 * @return * @throws Exception */ public static List<String> readSheetNames(String filePath) throws Exception { Workbook wb = null; List<String> sheetNames = new ArrayList<String>(); try { if (filePath.endsWith(EXCEL_XLS) || filePath.endsWith(EXCEL_XLSX)) { // 读取Excel文档 File file = new File(filePath); wb = getWorkbook(file); int sheetSize = wb.getNumberOfSheets(); // 遍历sheet页 for (int i = 0; i < sheetSize; i++) { Sheet sheet = wb.getSheetAt(i); sheetNames.add(sheet.getSheetName()); } } else { throw new BaseException(EPowerResultCode.JUDGE_EXCEL_FILE); } return sheetNames; } catch (FileNotFoundException e) { log.error(e.getMessage()); throw e; } finally { if (wb != null) { wb.close(); } } } /** * 读取excel中所有sheet的标题 * * @return */ public static List<String> readSheetTitles(String filePath) throws Exception { Workbook wb = null; List<String> titleList = new ArrayList<String>(); try { if (filePath.endsWith(EXCEL_XLS) || filePath.endsWith(EXCEL_XLSX)) { // 读取Excel文档 File file = new File(filePath); wb = getWorkbook(file); int sheetSize = wb.getNumberOfSheets(); for (int i = 0; i < sheetSize; i++) { Sheet sheet = wb.getSheetAt(i); Row row = sheet.getRow(0);//默认第一行为表头 short lastCellNum = row.getLastCellNum();//共有多少列 for (int j = 0; j < lastCellNum; j++) { Cell cell = row.getCell(j); titleList.add(cell.getStringCellValue().trim()); } } } return titleList; } catch (Exception e) { log.error(e.getMessage()); throw e; } finally { if (wb != null) { wb.close(); } } } /** * 导出文件 * @param request * @param response * @param wb * @param fileName */ public static void exportFile(HttpServletRequest request, HttpServletResponse response, Workbook wb, String fileName) throws Exception{ String userAgent = request.getHeader("USER-AGENT"); if (userAgent.contains("MSIE")) {// IE浏览器 fileName = URLEncoder.encode(fileName, "UTF8"); } else if (userAgent.contains("Mozilla")) {// google,火狐浏览器 fileName = new String(fileName.getBytes(), "ISO8859-1"); } else { fileName = URLEncoder.encode(fileName, "UTF8");// 其他浏览器 } response.setContentType("application/octet-stream;charset=UTF-8"); response.addHeader("Content-Disposition", "attachment;filename=" + fileName); OutputStream outputStream = response.getOutputStream(); wb.write(outputStream); } }
二、Excel样式设置工具类
/** * 导出的Excel单元格样式设置 */ public class ExcelStyleUtil { /** * 表头字体 * * @return */ public static Font headerFoot(Workbook wb) { Font headerFont = wb.createFont(); headerFont.setFontName("微软雅黑"); headerFont.setFontHeightInPoints((short) 13); headerFont.setBold(true); // headerFont.setColor(HSSFColor.HSSFColorPredefined.BLACK.getIndex()); headerFont.setColor(IndexedColors.BLACK.getIndex()); return headerFont; } /** * 正文字体 * * @param wb * @return */ public static Font contextFont(Workbook wb) { Font contextFont = wb.createFont(); contextFont.setFontName("微软雅黑"); contextFont.setFontHeightInPoints((short) 13); contextFont.setBold(false); contextFont.setColor(IndexedColors.BLACK.getIndex()); // contextFont.setColor(HSSFColor.HSSFColorPredefined.BLACK.getIndex()); return contextFont; } /** * 表头样式-左右上下居中 * * @param wb * @return */ public static CellStyle headerStyle(Workbook wb) { CellStyle headerStyle = wb.createCellStyle(); Font font = headerFoot(wb); headerStyle.setFont(font); headerStyle.setAlignment(HorizontalAlignment.CENTER);//水平居中 headerStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中 headerStyle.setLocked(true);//锁定 headerStyle.setWrapText(false);// 自动换行 headerStyle.setBorderBottom(BorderStyle.THIN);//下边框 headerStyle.setBorderTop(BorderStyle.THIN);//上边框 headerStyle.setBorderLeft(BorderStyle.THIN);//左 headerStyle.setBorderRight(BorderStyle.THIN);//右 return headerStyle; } /** * 单元格样式 - 水平、垂直居中 * * @param wb * @return */ public static CellStyle contextAlignCenterStyle(Workbook wb) { CellStyle style = wb.createCellStyle(); Font font = contextFont(wb); style.setFont(font); style.setAlignment(HorizontalAlignment.CENTER);//水平居中 style.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中 style.setLocked(true); style.setWrapText(true);// 自动换行 style.setBorderBottom(BorderStyle.THIN);//下边框 style.setBorderTop(BorderStyle.THIN);//上边框 style.setBorderLeft(BorderStyle.THIN);//左 style.setBorderRight(BorderStyle.THIN);//右 return style; } /** * 单元格样式-无左边框 * @param wb * @return */ public static CellStyle contextNoLeftBorder(Workbook wb){ CellStyle style = wb.createCellStyle(); Font font = contextFont(wb); style.setFont(font); style.setAlignment(HorizontalAlignment.CENTER);//水平居中 style.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中 style.setLocked(true); style.setWrapText(true);// 自动换行 style.setBorderBottom(BorderStyle.THIN);//下边框 style.setBorderTop(BorderStyle.THIN);//上边框 style.setBorderRight(BorderStyle.THIN);//右 return style; } /** * 单元格样式-无左右边框 * @param wb * @return */ public static CellStyle contextNoLeftRightBorder(Workbook wb){ CellStyle style = wb.createCellStyle(); Font font = contextFont(wb); style.setFont(font); style.setAlignment(HorizontalAlignment.CENTER);//水平居中 style.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中 style.setLocked(true); style.setWrapText(true);// 自动换行 style.setBorderBottom(BorderStyle.THIN);//下边框 style.setBorderTop(BorderStyle.THIN);//上边框 return style; } }
三、写入Excel简单示例
public void testWriteExcel(HttpServletRequest request, HttpServletResponse response){ //1.创建book Workbook wb = new XSSFWorkbook(); Sheet sheet = wb.createSheet("sheet名称,可为空"); //2.创建sheet sheet.createFreezePane(1, 2, 0, 0);//冻结首列和前两行 CellStyle headerStyle = ExcelStyleUtil.headerStyle(wb); //3.创建行 Row row0 = sheet.createRow(0); //4.创建单元格 Cell cell00 = row0.createCell(0); cell00.setCellStyle(headerStyle);//设置单元格样式 cell00.setCellValue("单元格值"); CellRangeAddress mergeReion = new CellRangeAddress(0, 0, 0, 2); sheet.addMergedRegion(mergeReion);//合并首行的前两个单元格 //(1)第二行设置表头 Row row1 = sheet.createRow(1); for (int i = 0; i < titles.size(); i++) { Object title = titles.get(i); Cell cell1i = row1.createCell(i); cell1i.setCellValue(String.valueOf(title)); cell1i.setCellStyle(headerStyle); } //(2)下面设置表体数据:创建10行3列的表体 CellStyle contextStyle = ExcelStyleUtil.contextAlignCenterStyle(wb);//内容样式 for (int i = 0; i < 10; i++) { Row rowi = sheet.createRow(i + 2); for(int j=0;j<3;j++){ Cell cellij = rowi.createCell(j); sheet.setColumnWidth(j,5000);//设置列宽 cellij.setCellStyle(contextStyle); } } //(3)导出到浏览器 try{ ExcelUtilByPOI.exportFile(request,response,wb,"文件名");//调用工具方法 }catch (Exception e){ throw new BaseException(EPowerResultCode.DOWNLOAD_FILE_FAIL); } }
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