Java 多级表头导出 Excel - 使用 Apache POI 库

要将多级表头导出到Excel，可以使用Apache POI库来实现。以下是一个示例代码，演示了如何将多级表头导出到Excel。\n\njava\nimport org.apache.poi.ss.usermodel.*;\nimport org.apache.poi.xssf.usermodel.XSSFWorkbook;\n\nimport java.io.FileOutputStream;\nimport java.io.IOException;\nimport java.util.List;\n\npublic class ExcelExporter {\n\n public void export(List<ExportEventResultVO> data, String filePath) throws IOException {\n Workbook workbook = new XSSFWorkbook();\n Sheet sheet = workbook.createSheet("Sheet1");\n\n // 创建表头\n createHeader(sheet);\n\n // 填充数据\n fillData(sheet, data);\n\n // 保存文件\n FileOutputStream fileOut = new FileOutputStream(filePath);\n workbook.write(fileOut);\n fileOut.close();\n\n // 关闭工作簿\n workbook.close();\n }\n\n private void createHeader(Sheet sheet) {\n Row headerRow1 = sheet.createRow(0);\n Row headerRow2 = sheet.createRow(1);\n Row headerRow3 = sheet.createRow(2);\n\n // 设置表头单元格样式\n CellStyle headerCellStyle = sheet.getWorkbook().createCellStyle();\n headerCellStyle.setAlignment(HorizontalAlignment.CENTER);\n headerCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);\n\n // 创建表头单元格\n Cell cell1 = headerRow1.createCell(0);\n cell1.setCellValue("事件编号");\n cell1.setCellStyle(headerCellStyle);\n\n Cell cell2 = headerRow1.createCell(1);\n cell2.setCellValue("主题");\n cell2.setCellStyle(headerCellStyle);\n\n Cell cell3 = headerRow1.createCell(2);\n cell3.setCellValue("事件类型");\n cell3.setCellStyle(headerCellStyle);\n\n Cell cell4 = headerRow1.createCell(3);\n cell4.setCellValue("上报人");\n cell4.setCellStyle(headerCellStyle);\n\n Cell cell5 = headerRow1.createCell(4);\n cell5.setCellValue("联系电话");\n cell5.setCellStyle(headerCellStyle);\n\n Cell cell6 = headerRow1.createCell(5);\n cell6.setCellValue("事件状态");\n cell6.setCellStyle(headerCellStyle);\n\n Cell cell7 = headerRow1.createCell(6);\n cell7.setCellValue("上报时间");\n cell7.setCellStyle(headerCellStyle);\n\n Cell cell8 = headerRow2.createCell(6);\n cell8.setCellValue("流程详情");\n cell8.setCellStyle(headerCellStyle);\n\n Cell cell9 = headerRow3.createCell(0);\n cell9.setCellValue("人员");\n cell9.setCellStyle(headerCellStyle);\n\n Cell cell10 = headerRow3.createCell(1);\n cell10.setCellValue("部门");\n cell10.setCellStyle(headerCellStyle);\n\n Cell cell11 = headerRow3.createCell(2);\n cell11.setCellValue("时间");\n cell11.setCellStyle(headerCellStyle);\n\n // 合并表头单元格\n sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, 5));\n sheet.addMergedRegion(new CellRangeAddress(0, 0, 6, 8));\n sheet.addMergedRegion(new CellRangeAddress(1, 2, 6, 6));\n }\n\n private void fillData(Sheet sheet, List<ExportEventResultVO> data) {\n int rowIndex = 3;\n\n // 设置数据单元格样式\n CellStyle dataCellStyle = sheet.getWorkbook().createCellStyle();\n dataCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);\n\n for (ExportEventResultVO result : data) {\n Row row = sheet.createRow(rowIndex++);\n\n Cell cell1 = row.createCell(0);\n cell1.setCellValue(result.getIncidentNo());\n cell1.setCellStyle(dataCellStyle);\n\n Cell cell2 = row.createCell(1);\n cell2.setCellValue(result.getSubject());\n cell2.setCellStyle(dataCellStyle);\n\n Cell cell3 = row.createCell(2);\n cell3.setCellValue(result.getType());\n cell3.setCellStyle(dataCellStyle);\n\n Cell cell4 = row.createCell(3);\n cell4.setCellValue(result.getSbr());\n cell4.setCellStyle(dataCellStyle);\n\n Cell cell5 = row.createCell(4);\n cell5.setCellValue(result.getLxdh());\n cell5.setCellStyle(dataCellStyle);\n\n Cell cell6 = row.createCell(5);\n cell6.setCellValue(result.getStatus());\n cell6.setCellStyle(dataCellStyle);\n\n Cell cell7 = row.createCell(6);\n cell7.setCellValue(result.getCreateTime());\n cell7.setCellStyle(dataCellStyle);\n\n List<ExportEventStepDetailsVO> stepDetails = result.getExportEventStepDetails();\n if (stepDetails != null && !stepDetails.isEmpty()) {\n int mergeStartRow = rowIndex - 1;\n int mergeEndRow = rowIndex + stepDetails.size() - 2;\n\n for (ExportEventStepDetailsVO stepDetail : stepDetails) {\n Row detailRow = sheet.createRow(rowIndex++);\n\n Cell cell8 = detailRow.createCell(6);\n cell8.setCellValue(stepDetail.getPerson());\n cell8.setCellStyle(dataCellStyle);\n\n Cell cell9 = detailRow.createCell(7);\n cell9.setCellValue(stepDetail.getDepart());\n cell9.setCellStyle(dataCellStyle);\n\n Cell cell10 = detailRow.createCell(8);\n cell10.setCellValue(stepDetail.getTime());\n cell10.setCellStyle(dataCellStyle);\n }\n\n // 合并流程详情单元格\n sheet.addMergedRegion(new CellRangeAddress(mergeStartRow, mergeEndRow, 6, 6));\n }\n }\n }\n\n}\n\n\n在上述代码中，export方法接受一个ExportEventResultVO类型的列表和一个文件路径作为参数，将数据导出到指定路径的Excel文件中。\n\n首先，创建一个XSSFWorkbook实例，用于表示工作簿。然后，使用工作簿创建一个名为"Sheet1"的工作表。\n\n接下来，调用createHeader方法创建表头。该方法会创建三行表头，并设置单元格样式和值。表头的样式使用居中对齐，同时表头的合并使用CellRangeAddress类来实现。\n\n然后，调用fillData方法填充数据。该方法会遍历数据列表，为每个数据对象创建一行，并设置单元格样式和值。如果数据对象中包含流程详情，会在该行下方创建多行流程详情数据，并合并流程详情单元格。\n\n最后，调用FileOutputStream类将工作簿保存到指定文件路径，并关闭工作簿。\n\n要使用该导出器，可以按照以下示例代码调用：\n\njava\npublic class Main {\n\n public static void main(String[] args) {\n // 准备数据\n List<ExportEventResultVO> data = new ArrayList<>();\n ExportEventResultVO result1 = new ExportEventResultVO();\n result1.setIncidentNo("001");\n result1.setSubject("主题1");\n result1.setType("类型1");\n result1.setSbr("上报人1");\n result1.setLxdh("联系电话1");\n result1.setStatus("状态1");\n result1.setCreateTime("上报时间1");\n\n List<ExportEventStepDetailsVO> stepDetails1 = new ArrayList<>();\n ExportEventStepDetailsVO stepDetail1 = new ExportEventStepDetailsVO();\n stepDetail1.setPerson("人员1");\n stepDetail1.setDepart("部门1");\n stepDetail1.setTime("时间1");\n stepDetails1.add(stepDetail1);\n\n ExportEventStepDetailsVO stepDetail2 = new ExportEventStepDetailsVO();\n stepDetail2.setPerson("人员2");\n stepDetail2.setDepart("部门2");\n stepDetail2.setTime("时间2");\n stepDetails1.add(stepDetail2);\n\n result1.setExportEventStepDetails(stepDetails1);\n\n ExportEventResultVO result2 = new ExportEventResultVO();\n result2.setIncidentNo("002");\n result2.setSubject("主题2");\n result2.setType("类型2");\n result2.setSbr("上报人2");\n result2.setLxdh("联系电话2");\n result2.setStatus("状态2");\n result2.setCreateTime("上报时间2");\n\n List<ExportEventStepDetailsVO> stepDetails2 = new ArrayList<>();\n ExportEventStepDetailsVO stepDetail3 = new ExportEventStepDetailsVO();\n stepDetail3.setPerson("人员3");\n stepDetail3.setDepart("部门3");\n stepDetail3.setTime("时间3");\n stepDetails2.add(stepDetail3);\n\n result2.setExportEventStepDetails(stepDetails2);\n\n data.add(result1);\n data.add(result2);\n\n // 导出数据到Excel\n ExcelExporter exporter = new ExcelExporter();\n try {\n exporter.export(data, "output.xlsx");\n System.out.println("导出成功！");\n } catch (IOException e) {\n e.printStackTrace();\n }\n }\n\n}\n\n\n在上述示例代码中，我们首先准备了一些测试数据，包括两个ExportEventResultVO对象，每个对象都包含了一个流程详情列表。\n\n然后，创建了一个ExcelExporter实例，并调用export方法将数据导出到名为"output.xlsx"的Excel文件中。\n\n导出完成后，控制台会输出"导出成功！"。导出的Excel文件中会包含表头和数据，多级表头的部分会被合并。